View Full Version : [Space] NASA - STS Program - Space Shuttle RTF
Discussione ufficiale
NASA
National Space Transportation System
Space Shuttle Program
http://www.cs.toronto.edu/XPL/77_1014l.jpg
Nome ufficiale: National Space Transportation System (Space Shuttle Program)
Tipo: Human Spaceflight - Esplorazione e utilizzazione orbita bassa terrestre, lancio e recupero satelliti, costruzione e rifornimento Space Station Freedom (poi International Space Station).
Stato: Terminato (21/07/2011).
Sito ufficiale: http://www.nasa.gov/mission_pages/shuttle/main/index.html
________________________
Space Shuttle Return To Flight Program progress news:
Final engine test-fired for shuttle return to flight
NASA NEWS RELEASE
Posted: August 20, 2004
Engineers at NASA's Stennis Space Center (SSC) in Mississippi have successfully tested what's expected to be the last of three Space Shuttle Main Engines (SSMEs) that will carry the next shuttle into orbit.
The engine tested Thursday will be shipped to NASA's Kennedy Space Center, Fla., for installation on Space Shuttle Discovery for its Return to Flight mission, designated STS- 114. NASA plans to launch Discovery to the International Space Station no earlier than March 2005.
The test began at about 9:10 p.m. EDT August 19. It ran for 520 seconds, the length of time it takes a Space Shuttle to reach orbit. Initial indications are all test objectives were successfully met.
"Piece by piece, milestone by milestone, we're getting closer to flying the Shuttle again," said Michael Kostelnik, deputy associate administrator for International Space Station and Space Shuttle Programs. "Today's engine test is another important step to make sure we give the STS-114 crew a safe ride to and from the Space Station."
"Our NASA and contractor team has continued to work hard over the past year and a half to make sure the Shuttle's main engine -- this incredible piece of machinery -- maintains its safety record," said Miguel Rodriguez, director of the Propulsion Test Directorate at SSC. "All the effort will pay off when we see Discovery lift off next year."
Engineers conduct rigorous testing to verify that an engine is ready to fly. Developed in the 1970s, the Space Shuttle Main Engine is the most advanced liquid-fueled rocket engine ever built and the first reusable one.
Temperatures inside the engines reach 6,000 degrees Fahrenheit -- hot enough to melt iron -- and the pressure mounts to as high as 6,000 pounds per square inch. During the eight-and-a-half minutes the Shuttle's three Main Engines burn, they produce energy equivalent to 23 Hoover Dams -- about 37 million horsepower. Each engine is 14 feet long, weighs about 7,000 pounds and is seven-and-a-half feet in diameter at the end of its nozzle. It generates almost 400,000 pounds of thrust.
"The successful completion of this test is another milestone in our efforts to return the Space Shuttle safely to flight," said Gene Goldman, manager of the Space Shuttle Main Engine Project Office at NASA's Marshall Space Flight Center in Huntsville, Ala. "There has been a tremendous effort by the team at Stennis, both civil servant and contractor, to ready the engines for flight. Their diligent attention to detail is critical to the safe and reliable performance of the engines."
The Rocketdyne Propulsion and Power division of The Boeing Co. of Canoga Park, Calif., manufactures the Shuttle's Main Engines. Pratt and Whitney, a United Technologies Company of West Palm Beach, Fla., builds the high-pressure turbopumps. NASA's Space Shuttle Main Engine Project Office administers the main engine program. SSC conducts engine tests.
We are processing 7 days a week 24 hours a day on Discovery (Ov-103) and Atlantis (OV-104). 6 days a week 16 hours a day on OV-105.
Our work rules, that were developed after the Challenger accident, Do not allow a person to work more that 60 hours a week or more than 7 days in a row.
With the schedule as it is we are scheduled to work through the Thanksgiving and Christmas/New Years holidays.
shuttle_guy
NASA sets May date for first post-Columbia shuttle launch
NASA NEWS RELEASE
Posted: October 29, 2004
After an extensive review, NASA is planning its Return to Flight space shuttle mission, designated STS-114, for a launch window that opens in May 2005.
NASA's Space Flight Leadership Council met today to consider a recommendation from the Space Shuttle Program to revise the Return to Flight target launch window to May 2005. The council endorsed the recommendation the May window, which opens from May 12 to June 3, 2005, is achievable.
The agency was working toward a launch planning window that opens in March 2005, before a series of hurricanes impacted operations at multiple NASA facilities. NASA's Kennedy Space Center, Fla., Marshall Space Flight Center, Ala., Stennis Space Center, Miss., and Michoud Assembly Facility, La., all experienced shutdowns in preparation for one or more of the four hurricanes in August and September, resulting in delays on Return to Flight work.
"After four hurricanes in a row impacted our centers and our workers, it became clear, we needed to step back and evaluate the work in respect to the launch planning date," said William Readdy, Space Flight Leadership Council co-chair and associate administrator for Space Operations. "We asked the program to go back and evaluate May, and they reported the milestones are lining up. The May launch planning window is based on solid analysis and input from across all elements of the program," he said.
NASA's Space Flight Leadership Council is co-chaired by Readdy and Walt Cantrell, deputy chief engineer for the agency's Independent Technical Authority. The council includes the directors for NASA's four Space Operations centers, Chief Officer for Safety and Mission Assurance Bryan O'Connor, and Deputy Associate Administrator for International Space Station and Space Shuttle Programs Michael Kostelnik.
ah, li avevano interrotti i voli shuttle? non lo sapevo :eek:
Originariamente inviato da thotgor
ah, li avevano interrotti i voli shuttle? non lo sapevo :eek:
come non lo sapevi, mai sentito della tragedia del Columbia?
Originariamente inviato da GioFX
come non lo sapevi, mai sentito della tragedia del Columbia?
si, ma pensavo avessero già ripreso. O almeno, non avessero smesso per cosi tanto. :eek:
Originariamente inviato da thotgor
si, ma pensavo avessero già ripreso. O almeno, non avessero smesso per cosi tanto. :eek:
C'è stata una commissione di inchiesta che ha indicato, oltre alle cause del disastro, anche tutte le nuove misure da adottare e le modifiche al programma STS, soprattutto per la fase di lancio, e tutte queste features da implementare hanno richiesto, oltre a 10 mesi di indagini, un altro bel anno e mezzo per avere la prima launch window, a marzo 2005 (ora spostata a maggio a causa dei 4 uragani che si sono abbattuti sulla Florida nel mese di settembre). Tieni conto che si sta lavorando 24 ore al giorno sull'orbiter 104 (Discorvery, quello che partirà per primo) e 18-20 sugli altri 2, non per ultimo ora le finestre di lancio sono inferiori di numero dato che hanno eliminato i lanci notturni.
Costo dell'aggiornamento?
Shuttle tank arrives at Kennedy Space Center
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: January 5, 2005
The upgraded external fuel tank that will launch as part of the first post-Columbia shuttle mission in May arrived at the Kennedy Space Center today, setting the stage for attachment to a set of solid-fuel boosters.
http://www.spaceflightnow.com/shuttle/sts114/050105tankksc/tankksc1.jpg
The covered barge ferrying the re-designed space shuttle external fuel tank arrives at Kennedy Space Center as seen from atop the press site mound. Photo: William Harwood
A barge carrying external tank 120 was tied to a dock near the Vehicle Assembly Building around 2 p.m. after a five-day voyage from NASA's Michoud Assembly Plant near New Orleans.
"This is a very important day for the nation and for its space program," said external tank project manager Sandy Coleman. "This is a big boost (to morale). We're all excited we have all of the vehicle here at the Kennedy Space Center."
The shuttle Columbia was destroyed during re-entry Feb. 1, 2003, because of a crack or hole in its left wing that was caused by the impact of a piece of insulating foam that broke free from the orbiter's external tank during launch.
http://www.spaceflightnow.com/shuttle/sts114/050105tankksc/tankksc2.jpg
This view of the tank arrival shows the famous countdown clock and flag at the Kennedy Space Center press site with launch pad 39A in the background. Photo: William Harwood
The foam in question has been eliminated from the new tanks and other improvements have been implemented that, taken together, should make ET-120 "the safest and most reliable tank that's ever been produced," Coleman said.
The tank arrived at KSC a day early. It will be off loaded and towed to the Vehicle Assembly Building early Thursday. NASA plans a media photo opportunity and news conference later in the morning.
Shuttle commander Eileen Collins and the crew of the STS-114 mission are scheduled to visit the Kennedy Space Center Friday to view the tank and meet with spaceport workers. They also plan to hold their first question-and-answer session with reporters before heading back to Houston.
http://www.spaceflightnow.com/shuttle/sts114/050105tankksc/tankksc3.jpg
The barge is maneuvered into the tank unloading area. Photo: William Harwood
All elements in place for shuttle's return to flight
NASA NEWS RELEASE
Posted: January 6, 2005
NASA marked a major milestone for the Space Shuttle's Return to Flight, as the redesigned External Tank rolled out today from the barge that carried it to the agency's Kennedy Space Center.
http://www.spaceflightnow.com/shuttle/sts114/050106tankoffload/tankoffload.jpg
The external tank is offloaded from the covered barge with shuttle officials and members of the news media looking on. Photo: NASA-KSC
The tank was taken to the Vehicle Assembly Building (VAB) for a final checkout. It will eventually be attached to the twin Solid Rocket Boosters and the Space Shuttle Discovery for its Return to Flight mission, STS-114.
"With the arrival of the External Tank, all of the elements of the Space Shuttle system are in place for Return to Flight," said Michael Kostelnik, deputy associate administrator for International Space Station and Space Shuttle programs. "This improved tank will be the safest we've ever flown. The modifications we have made will ensure the Shuttle completes its long- term mission of assembling the International Space Station," he said.
NASA and Lockheed Martin Corp. spent nearly two years modifying the 15-story, rust-colored tank to make it safer. Among dozens of changes is a redesigned forward bipod fitting to reduce the risk to the Shuttle from falling debris during ascent. Reducing the debris risk was a key recommendation of the Columbia Accident Investigation Board.
"Although we can never completely eliminate insulating foam coming off the External Tank, we have absolute confidence we have eliminated the type of debris that caused the loss of Columbia," said Bill Parsons, Space Shuttle program manager. "This tank is safe to fly the Return to Flight mission."
The External Tank arrived at KSC after a 900-mile journey at sea. It departed NASA's Michoud Assembly Facility in New Orleans on Dec. 31. It was transported via Pegasus, NASA's specially designed barge. The Solid Rocket Booster retrieval ship Liberty Star brought the barge to Port Canaveral yesterday. The barge was moved by tugs to the KSC Turn Basin, the tank off-loaded and transported to the Vehicle Assembly Building.
"The team here at KSC is tremendously excited to receive the final Shuttle element for the Return to Flight mission," said Mike Wetmore, director of Shuttle processing at KSC. "We have an experienced team in place that will complete the final checkout and processing of the tank and prepare it for its final journey out to the launch pad before flight."
http://www.spaceflightnow.com/shuttle/sts114/050106tankoffload/tankvab.jpg
The tank was moved to the VAB. Photo: NASA-KSC
In the VAB, the tank will be raised to a vertical position. It will be lifted high up in the transfer aisle into the "checkout cell," where the tank's mechanical, electrical and thermal protection systems are inspected. The tank will also undergo new processes resulting from its re-design, including inspection of the bipod heater and External Tank separation camera.
The tank will be prepared for "mating" to the Shuttle's Solid Rocket Boosters. When preparations are complete, the tank will be lifted from the checkout cell, moved across the transfer aisle and into High Bay 1. It will be lowered and attached to the boosters, which are sitting on the Mobile Launch Platform.
The arrival of the External Tank, the largest element of the Space Shuttle system, follows other recent Return to Flight milestones, including the "stacking" of the Solid Rocket Boosters in the Vehicle Assembly Building and installation of the Space Shuttle Main Engines into Discovery. The External Tank is the only Shuttle component not recovered after launch and reused.
The Return to Flight mission is targeted for a launch window beginning in May. The seven-member Discovery crew will fly to the International Space Station primarily to test and evaluate new procedures for flight safety, Shuttle inspections and repair techniques.
The Space Shuttle Propulsion Office at NASA's Marshall Space Flight Center, Huntsville, Ala., manages the tank project. Lockheed Martin Space Systems Co., New Orleans, is the primary contractor.
Originariamente inviato da Duncan
Costo dell'aggiornamento?
E fonte dei proventi? Sarei felice di sapere che i fondi ci sono ancora.....anche se non capisco da dove vengano!
spinbird
07-01-2005, 22:57
rapido riepilogo, quali sono quelli attualmente esistenti e ancora operativi?
challenger e columbia se ne sono andati:(
ci sono il discovery, atlantis e poi se non erro anche l'endeavour, anche se non l'ho letto nelle tue citazioni
Originariamente inviato da lowenz
E fonte dei proventi? Sarei felice di sapere che i fondi ci sono ancora.....anche se non capisco da dove vengano!
I fondi dei progetti NASA, essendo questa un'ente governativo, sono totalmente a carico dello stato, e quindi del contribuente americano. I costi del progetto STS non li conosco nel dettaglio, tuttavia fa conto che è pari a circa un sesto del budget annuale, che ammonta a 16 miliardi di dollari per il F.Y. 2005 (quello dell'ESA, ad esempio, il secondo come entità dopo quello NASA, è pari ad appena 2,5 miliardi).
Originariamente inviato da spinbird
rapido riepilogo, quali sono quelli attualmente esistenti e ancora operativi?
challenger e columbia se ne sono andati:(
ci sono il discovery, atlantis e poi se non erro anche l'endeavour, anche se non l'ho letto nelle tue citazioni
Dei 4 che erano previsti per la flotta del programma STS (Space Transportation System), ne rimangono 3:
- Discovery (OV-103), dove OV sta per Orbiter Vehicle
- Atlantis (OV-104)
- Endeavour (OV-105)
L'Enterprise è stato il primo (OV-101), doveva chiamarsi Constitution in onore del bicentenario della costituzione americana (correva l'anno 1976), ma era un prototipo non abilitato per il volo, poi fu costruito il Columbia (OV-102), il primo a volare (1981), poi fu la volta del Discovery (OV-103), e infine l'Atlantis (OV-104). L'Endeavour fu invece costruito per sostituire il Challenger (OV-99).
Oggi non sarebbe conveniente in termini di costi e ma anche come utiltà, anche perchè il programma dovrà essere chiuso e il resto degli orbiter mandati in pensione entro il 2011, causa scadenza della certificazione per il volo.
se non sbaglio l'Enterprise era stato utilizzato per simulazioni di volo planato in atmosfera, non è abilitato per il volo orbitale
Space shuttle program poised for return in May
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: February 18, 2004
NASA managers today set May 15 as the target launch date for the first post-Columbia shuttle mission, saying they are confident remaining technical issues, an independent review and a mountain of paperwork can be closed out in time for flight.
Launch director Michael Leinbach said the processing schedule includes about 12 days of contingency time to handle unexpected problems between now and then and "we feel good about that date."
The current schedule calls for engineers to attach Discovery's redesigned external fuel tank to a pair of already assembled solid-fuel boosters around Feb. 25 and for Discovery to be bolted to the side of the tank March 18.
The assembled spacecraft then will be hauled to launch pad 39B on March 25 and the tank will be loaded with supercold liquid oxygen and liquid hydrogen rocket fuel April 7 in a test that will serve as a dress rehearsal for launch.
Commander Eileen Collins and her six crewmates plan to strap in aboard Discovery on April 29 for a practice countdown and if all goes well, the actual countdown will begin May 12 for a launch around 3:50 p.m. on May 15.
Columbia's launch window extends to June 3, based on the orbit of the shuttle's destination - the international space station - and because of a self-imposed requirement to not only launch the first two post-Columbia flights in daylight but also to ensure external tank separation in sunlight for photo documentation.
If NASA can't get Discovery off the ground by June 3 or thereabouts, the flight will slip to mid July. But Leinbach is optimistic it won't come to that.
"After the tanking test is done, the remainder of the pad flow is very standard to us," he said. "And so I'll just tell you, this date feels real good to me."
Fifteen of the 29 recommendations made by the Columbia Accident Investigation Board must be completed before Discovery's return to flight. As of today, only seven of those 15 have been fully addressed to the satisfaction of an independent panel charged with monitoring NASA's implementation of those recommendations.
But on Thursday, panel co-chairman Richard Covey, a Boeing executive and former shuttle commander, said he saw no major roadblocks to closing out the remaining items before the board ends its work March 31. William Readdy, NASA's associate administrator for space operations agreed and told reporters today "we have every expectation we are going to close all of them."
"We have a continuing dialogue with the three panels that they have," he said. "At this point, we really don't see any show stoppers, that's been their commentary all along, so we expect to close all of them."
Major technical questions remain, however, including work to determine how much damage the shuttle's wing leading edges and heat-shield tiles can withstand before repairs are needed.
The Spaceflight Leadership Council, co-chaired by Readdy, met today at the Kennedy Space Center and approved plans to test three rudimentary tile and leading edge repair techniques during Discovery's mission. But those techniques will not be certified before launch and as such would only be used in a true emergency.
Readdy said any repair techniques would have to be tested in space before certification and in any case, the kind of external tank foam debris blamed in the Columbia disaster has been eliminated. Other potential weak spots have been addressed as well.
"Given the depth of inspection that we've gone into in each and every last subsystem and element of the program, I'd be very, very surprised if we had any kind of damage as a result of debris shedding," he said. "We just heard ... a very thorough debrief on the analysis they have conducted. That analysis continues, but I think it should give everyone tremendous confidence that we have done what we needed to to eliminate critical debris from the external tank and other sources on the solid rocket motors."
Combined with efforts to fully characterize the strength of the thermal protection system and improvements in other systems, "we'll be flying much more safely than we ever have before."
Walter Cantrell, deputy chief engineer for NASA's new Independent Technical Authority and co-chairman of the agency's Spaceflight Leadership Council, said the Return to Flight Task Group chaired by Covey and Thomas Stafford has participated in the engineering discussions and understands the processing schedule.
Regarding the open items in the RTF recommendations, Cantrell said "we have received from the Stafford-Covey group their expectations that, if satisfied by us, they could be comfortable in saying that their assessment would be that we have complied with the intent of the CAIB recommendations. Some of them are obviously harder than others because of timing, given that the Stafford-Covey group wants to be able to give its recommendations to the administrator at least one month before return to flight.
"We're in careful contact with them and know what we think we need to do and we know what they think we need to do," Cantrell said. "A significant number of their members participated today, not only listened but actually provided comments during the Spaceflight Leadership Council (meeting), so we're all tracking the same things.
"Our sense of it, and the last sense that we have from them, is there are no show stoppers, we're in very tight agreement on the schedule for closure. Anything can happen, but we do not anticipate that being a problem."
He said NASA had set higher standards "in almost every case" than the CAIB recommendations required and "we're holding ourselves to that raised bar."
"Obviously, we're going to comply with what Stafford-Covey is looking for and what the CAIB is looking for," he said. "But we are the ones who accept the risk and we've set that standard where we think it should be."
Altre info da shuttle_guy (insider United Space Alliance al Kennedy):
28 more launches
2005 3
2006, 7, 8, 9, 10 have 5 each.
The mandidate end of Shuttle is the END of 2010.
However there is an effort to reduce the number of launches by moving some logistical cargo to unmanned vehicles.
AlexGatti
20-02-2005, 21:17
Originariamente inviato da GioFX
Altre info da shuttle_guy (insider United Space Alliance al Kennedy):
28 more launches
2005 3
2006, 7, 8, 9, 10 have 5 each.
The mandidate end of Shuttle is the END of 2010.
However there is an effort to reduce the number of launches by moving some logistical cargo to unmanned vehicles.
Ok, e di 'sti 13 lanci che ci sono di qui alla fine del 2007 non ne possono impiegare neanche uno per rimettere a posto Hubble? Non ci credo.
jumpermax
20-02-2005, 21:28
Originariamente inviato da AlexGatti
Ok, e di 'sti 13 lanci che ci sono di qui alla fine del 2007 non ne possono impiegare neanche uno per rimettere a posto Hubble? Non ci credo.
c'è un bel problema: come procedura di sicurezza prevedono il trasbordo degli astronauti sulla stazione spaziale... e dall'orbita dell'Hubble lo shuttle non è in grado di attraccare alla stazione.
AlexGatti
20-02-2005, 22:08
Originariamente inviato da jumpermax
c'è un bel problema: come procedura di sicurezza prevedono il trasbordo degli astronauti sulla stazione spaziale... e dall'orbita dell'Hubble lo shuttle non è in grado di attraccare alla stazione.
Hmm, un po' come dire, "lo shuttle siamo sicuri che arriva in orbita, ma forse ci arriva fallato".
Insomma, o queste procedure di sicurezza sono oltremodo sovradimensionate in modo da rassicurare l'opinione pubblica (anche se in realtà non sono necessarie) oppure lo shuttle e veramente un tarambiccolo che sta su a fortuna e una volta che lo mandi su non c'è alcuna garanzia che torni giù intatto ne che tu lo riesca a riparare in volo.
Originariamente inviato da AlexGatti
Ok, e di 'sti 13 lanci che ci sono di qui alla fine del 2007 non ne possono impiegare neanche uno per rimettere a posto Hubble? Non ci credo.
Per motivi di sicurezza non sono più previste missioni al di fuori da quelle dirette alla ISS (orbita inclinazione 51,6°). Le rimanenti saranno dedicate al completamento della stazione, in modo da rispettare la data del 2010 per il grounding definitivo della flotta.
jumpermax
20-02-2005, 22:22
Originariamente inviato da AlexGatti
Hmm, un po' come dire, "lo shuttle siamo sicuri che arriva in orbita, ma forse ci arriva fallato".
Insomma, o queste procedure di sicurezza sono oltremodo sovradimensionate in modo da rassicurare l'opinione pubblica (anche se in realtà non sono necessarie) oppure lo shuttle e veramente un tarambiccolo che sta su a fortuna e una volta che lo mandi su non c'è alcuna garanzia che torni giù intatto ne che tu lo riesca a riparare in volo.
Sicuro quanto lo può essere sedersi sopra qualche migliaio di tonnellate di combustibile appiccare il fuoco ed arrivare in orbita... la questione non risolta in questo caso è quella delle piastrelle isolanti che se danneggiate non possono essere riparate in orbita. Per cui insomma lo shuttle non potrebbe più rientrare e sarebbe necessaria una missione di soccorso...
Originariamente inviato da AlexGatti
Hmm, un po' come dire, "lo shuttle siamo sicuri che arriva in orbita, ma forse ci arriva fallato".
Insomma, o queste procedure di sicurezza sono oltremodo sovradimensionate in modo da rassicurare l'opinione pubblica (anche se in realtà non sono necessarie) oppure lo shuttle e veramente un tarambiccolo che sta su a fortuna e una volta che lo mandi su non c'è alcuna garanzia che torni giù intatto ne che tu lo riesca a riparare in volo.
No, semplicemente per un'ispezione accurata delle termal tiles è necessario utilizzare l'ISS e il secondo Canadarm modificato, non basta quello dell'orbiter, inoltre occorre garantire all'equipaggio la possibilità di eseguire EVA (attività extra-veicolare) in tutta sicurezza.
Non è impossibile una missione shuttle per la terza e ultima Servicing Mission (SM-3, inizialmente prevista per il 2006), ma semplicemente il Congresso non la autorizzerà mai, sulla base delle considerazioni della CAIB e delle indicazioni dei responsabili STS della NASA.
Hubble sarà probabilmente parzialmente upgradato da una missione robotica. Una seconda lo spingerà in atmosfera.
Originariamente inviato da jumpermax
Sicuro quanto lo può essere sedersi sopra qualche migliaio di tonnellate di combustibile appiccare il fuoco ed arrivare in orbita... la questione non risolta in questo caso è quella delle piastrelle isolanti che se danneggiate non possono essere riparate in orbita. Per cui insomma lo shuttle non potrebbe più rientrare e sarebbe necessaria una missione di soccorso...
Esatto.
Infatti, nel rispettare le 15 (su 29) specifiche del CAIB, la NASA dovrà tenere pronta una seconda navetta (nel caso della prima missione del RTF, la STS-114 con il Discovery), probabilmente l'Atlantis, per essere lanciata entro 10 giorni dal lancio della prima.
NASA comunque prevedibilmente chiederà al Congresso di non dover eseguire questa operazione dopo i primi due lanci.
Il terzo lancio, l'ultimo di quest'anno (previsto per settembre), sarà il primo che riprenderà la costruzione dell'ISS, mentre le prime due saranno dedicate al testing delle tecniche di riparazione in orbita e alla riparazione dell'hardware sulla ISS, nonchè al rifornimento della stessa.
jumpermax
20-02-2005, 22:39
gio ma si sa qualcosa sulla navetta che prenderà il posto dello shuttle? E' vero che vogliono tornare al vettore tipo saturno V ?
AlexGatti
20-02-2005, 22:41
Originariamente inviato da GioFX
No, semplicemente per un'ispezione accurata del termal tiles è necessario utilizzare l'ISS e il secono Canadarm modificato, non basta quello dell'orbiter, e si deve garantire all'equipaggio la possibilità di eseguire EVA (attività extra-veicolare) in tutta sicurezza.
Non è impossibile una missione shuttle per la terza e ultima Servicing Mission (SM-3, inizialmente prevista per il 2006), ma semplicemente il Congresso non la autorizzerà mai, sulla base delle considerazioni della CAIB e le indicazioni dei responsabili STS della NASA.
Hubble sarà probabilmente parzialmente upgradato da una missione robotica. Una seconda lo spingerà in atmosfera.
Mah insomma secondo me equivale a dire che fin'ora siamo andati su "a culo" e ci è sempre andata bene.
Comunque per quel poco che ne so hubble non sarà upgradato ne riparato ma sarà spinto in atmosfera da una missione robotica, ovvero lo lasciano andare in malora.
La missione robotica di salvataggio era stata esclusa per motivi di costi/ difficoltà tecniche / tempistica.
Felice di essere smentito ovviamente.
Originariamente inviato da jumpermax
gio ma si sa qualcosa sulla navetta che prenderà il posto dello shuttle? E' vero che vogliono tornare al vettore tipo saturno V ?
Il CEV (crew exploration veichle) sarà un sistema modulare con un modulo simile all'Apollo Command Module, ma la composizione della navetta con diversi moduli sarà possibile in LEO (Low Earth Orbit). Tuttavia non vedrà mai alla luce un sistema che non preveda il rientro diretto in atmosfera, dato che un "docking" è una operazione mucho rischiosa.
Originariamente inviato da AlexGatti
Mah insomma secondo me equivale a dire che fin'ora siamo andati su "a culo" e ci è sempre andata bene.
Beh, questo ha sicuramente una base di verità. Ti ricordo che anche la routine nel settore aerospaziale è ancora molto sperimentale.
Comunque per quel poco che ne so hubble non sarà upgradato ne riparato ma sarà spinto in atmosfera da una missione robotica, ovvero lo lasciano andare in malora.
La missione robotica di salvataggio era stata esclusa per motivi di costi/ difficoltà tecniche / tempistica.
Felice di essere smentito ovviamente.
Si sta studiando una missione di supporto, ma ad oggi è ancora escluso l'uso dello shuttle.
Un'alternativa è quella, ma anch'essa costosissima e non priva di molti rischi... di "spingere" con un vettore l'HUBBLE all'orbita dell'ISS, ripararlo con una missione STS e lasciarlo ricadere nella sua orbita prevista.
LittleLux
21-02-2005, 00:21
Peccato che la Russia non ha fondi per ripescare il suo progetto di Shuttle (Buran, ormai abbandonato dalla fine degli anni ottanta)), che tra le altre cose pare fosse, per molti aspetti, più avanzato e versatile di quello USA....
http://spaceinfo.jaxa.jp/note/yujin/g/yuj1601.jpg
http://www.bornintheussr.com/wall-09.jpg
http://www.bornintheussr.com/wall-10.jpg
Qualche link:
http://en.wikipedia.org/wiki/Buran
http://liftoff.msfc.nasa.gov/rsa/buran.html
http://liftoff.msfc.nasa.gov/rsa/pics.html
...tuttavia, forse, non è detta l'ultima parola, sperem.
http://www.spacedaily.com/news/russia-space-general-01m.html
Originariamente inviato da LittleLux
Peccato che la Russia non ha fondi per ripescare il suo progetto di Shuttle (Buran, ormai abbandonato dalla fine degli anni ottanta)), che tra le altre cose pare fosse, per molti aspetti, più avanzato e versatile di quello USA....
...tuttavia, forse, non è detta l'ultima parola, sperem.
http://www.spacedaily.com/news/russia-space-general-01m.html
Il Buran era uno spettacolare sistema, come hai detto su molti fronti superioren allo Shuttle... tuttavia ripescarlo è impossibile, il solo esemplare operativo per il volo è stato riconvertito a museo e si trova al Gorky Park di Mosca, gli altri prototipi sono stati smantellati o distrutti.
Oltretutto sarebbe troppo costoso, e ormai per molti aspetti obsoleto. Tieni oltretutto conto che manca pure la materia prima, ovvero il vettore Energia, che esisteva un solo esemplare, prima di andare perso nel collasso dell'hangar con il secondo orbiter a Tyuratam.
LittleLux
21-02-2005, 13:05
Originariamente inviato da GioFX
Il Buran era uno spettacolare sistema, come hai detto su molti fronti superioren allo Shuttle... tuttavia ripescarlo è impossibile, il solo esemplare operativo per il volo è stato riconvertito a museo e si trova al Gorky Park di Mosca, gli altri prototipi sono stati smantellati o distrutti.
Oltretutto sarebbe troppo costoso, e ormai per molti aspetti obsoleto. Tieni oltretutto conto che manca pure la materia prima, ovvero il vettore Energia, che esisteva un solo esemplare, prima di andare perso nel collasso dell'hangar con il secondo orbiter a Tyuratam.
Quindi niente speranze per il futuro. E' un vero peccato.
Per quanto riguarda il prossimo orbiter nasa, invece, mi pare di capire che sarà alquanto diverso dall'attuale shuttle, è corretto?
Comunque, riguardo Buran ed altri progetti, ecco il LINK (http://www.buran.ru/htm/molniya.htm) , interessantissimo, sul produttore di quello shuttle.
Ciao
Originariamente inviato da LittleLux
Quindi niente speranze per il futuro. E' un vero peccato.
Per quanto riguarda il prossimo orbiter nasa, invece, mi pare di capire che sarà alquanto diverso dall'attuale shuttle, è corretto?
[/QUOTE]
esatto, vedi uno dei post più sopra.
Originariamente inviato da GioFX
esatto, vedi uno dei post più sopra.
hai qualche info specifiche (magari un confronto) sullo shuttle e sul suo futuro sostituto?
Tra l'altro mi pare che gli shuttle sono leggermente diversi tra loro.
Originariamente inviato da evelon
hai qualche info specifiche (magari un confronto) sullo shuttle e sul suo futuro sostituto?
Ancora no, il CEV non è stato ancora scelto tra i diversi progetti, che sono ancora in fase di sviluppo.
Shuttle external fuel tank mated to boosters
NASA-KSC NEWS RELEASE
Posted: March 1, 2005
NASA is marking a major step in assembling the space shuttle for its Return to Flight mission. Monday, workers successfully "mated," or attached, the redesigned external tank and twin solid rocket boosters (SRBs). The fuel tank and booster rockets will help launch space shuttle Discovery on its mission to the International Space Station, currently targeted for May 15-June 3.
http://spaceflightnow.com/shuttle/sts114/050301etmate/externaltank.jpg
An overhead crane moves the external tank inside the Vehicle Assembly Building for mating to the solid rocket boosters. Photo: NASA
The space shuttle's external tank was lifted by a giant crane and joined to the already assembled, or "stacked," boosters in the 52-story Vehicle Assembly Building (VAB) at NASA's Kennedy Space Center, Fla. Mating the tank with the boosters is another major step in readying the space shuttle system for flight.
Following integration and final checkout of the external tank with the SRBs, orbiter Discovery will join its propulsion components in the VAB. Discovery will roll over from its hangar, the Orbiter Processing Facility, later this month to mark the completion of Return to Flight processing. The orbiter then will be attached to the stack in the VAB.
The external tank will fly with several modifications, including two new forward bipod heaters at the forward attach fittings that connect the tank to the orbiter. NASA and Lockheed Martin Space Systems Co. spent nearly two years modifying the tank to make it safer.
http://spaceflightnow.com/shuttle/sts114/050301etmate/etmate.jpg
The external tank is moved into position for mating with the solid rocket boosters. Photo: NASA
During ET-SRB mating, the left and right boosters are bolted to the tank at both the forward, or top, and the aft, or tail, ends. At the forward end, a vertical bolt mechanism attaches each booster to the tank. On launch day, approximately two minutes after liftoff, the SRBs will separate from the ET when pyrotechnic devices fire to break the 25-inch, 62-pound steel bolts. One half of the bolt is caught in canister-like "bolt catchers" located on the tank; the other half remains with the boosters.
Discovery will also be the first flight with a modified bolt catcher, which was upgraded from a two-piece welded design to a one-piece, machine-made design. By eliminating the weld, the modified bolt catcher is structurally stronger than the original design.
Prior to orbiter Discovery joining the stack, final closeouts on the external tank will include attaching the new bolt catcher and electrical cable connections, as well as installing an aerodynamic fairing and the bi-pod struts, which are the attach points for the nose of the orbiter to the tank.
The external tank is the largest element of the space shuttle system, which also includes the orbiter, main engines and SRBs. It measures 27.6 feet wide and 154 feet tall. Despite the tank's size, the aluminum skin covering it is only an eighth of an inch thick in most areas. Yet it still withstands more than 6.5 million pounds of thrust during liftoff and ascent. The tank is the only Shuttle component that cannot be reused.
Shuttle mission simulation tests post-Columbia team
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: March 4, 2005
The shuttle Discovery docked with the international space station today in a dramatic mission simulation that included presumed foam debris impacts to the orbiter's right wing leading edge and an aft rocket pod during the make-believe climb to space.
http://spaceflightnow.com/shuttle/sts114/050304sim/050304firingroom.jpg
Senior managers, launch team members and reporters gather in the Firing Room to simulate liftoff of Discovery earlier this week. Photo: NASA
The simulation, which began Wednesday with a mock launch from the Kennedy Space Center, is designed to put NASA's post-Columbia management system to the test while giving the shuttle crew and mission control team a chance to sharpen their skills.
Flight directors and members of NASA's mission management team even staged faux news briefings complete with questions from public affairs officers playing the roles of reporters.
"It's been great. Everybody's played really hard," MMT Chairman Wayne Hale said late Friday. "This is like a real flight, they are playing hard and we've had a lot of emotion, which is good, that means people are taking it seriously, but it hasn't gotten out of hand. People are being reasonable in their conclusions and I think that's very good."
Said John Shannon, a senior member of NASA's mission management team: "This is like a play. This is our dress rehearsal. I'm just blown away by the fidelity of this thing, how many people are participating."
For launch, the MMT gathered at the Kennedy Space Center earlier this week for a full-fledged dress rehearsal countdown led by launch director Mike Leinbach and NASA test director Jeff Spaulding.
Five reporters, including this writer, were allowed to sit in on an early morning MMT meeting Wednesday to clear the launch team for a simulated fueling and later, observed the terminal countdown from the firing room in Kennedy's Launch Control Center.
The countdown was relatively straight forward and while a few problems cropped up that required extensive troubleshooting, the simulated liftoff occurred on time at 5:55 p.m. But seconds after launch, the simulation team began throwing problems at Discovery's crew and flight controllers in Houston, including simulated impacts by foam debris from Discovery's external fuel tank.
Columbia was brought down Feb. 1, 2003, by wing leading edge damage caused by a chunk of external fuel tank foam insulation that broke away during ascent.
Discovery's tank has been modified to prevent large pieces of foam from breaking off in flight. While it's not possible to completely eliminate foam shedding, Hale said Wednesday he's optimistic the tank will be deemed safe enough to launch after two years of work to minimize debris.
"In a perfect world, you would say the biggest thing that can come off the tank can't possibly hurt the (wing leading edge)," he said. "In a worst-on-worst kind of case, you can't say that, even after what we've done. But what we can say is in a realistic sense ... from what is reasonable to happen, we have sufficient safety margin."
To make absolutely sure the tank performs as expected, at least the first two shuttle missions will be treated as test flights. New high definition television tracking cameras will photograph Discovery's real launch in May with unprecedented resolution and other cameras on the shuttle, the tank itself and the orbiter's twin solid-fuel boosters will provide extensive photographic coverage during the climb to space.
In addition, cameras aboard two modified jets will "shoot" the shuttle through booster separation, the astronauts will photograph the tank in space and military spy satellites will snap classified photographs of the shuttle to look for signs of damage.
Sensors mounted just behind the wing leading edge panels will record the force and location of any impacts, the shuttle's crew will use laser sensors mounted on the end of a long boom to scrutinize the wing leading edges from the outside and the crew of the international space station will photograph the heat-shield tiles on the belly of the orbiter during Discovery's final approach.
The severity of any actual damage in a real flight will dictate NASA's response. Minor damage might be deemed acceptable for re-entry as is. More serious damage could raise the prospect of a spacewalk repair job and in cases where the issue was not clear cut - or the damage is obviously too severe for a repair - the astronauts could move into the space station and await rescue by another shuttle.
While no one expects any significant foam shedding during Discovery's May 15 launching, this week's simulation has forced mission managers to exercise all of the post-Columbia inspection techniques in a real-world scenario.
During Wednesday's mock launch, commander Eileen Collins had to deal with a fuel cell glitch seconds after liftoff and was told the center main engine's nozzle was leaking hydrogen. The shuttle's main engines shut down slightly early, resulting in a 35 foot per second shortfall in velocity. To save fuel, the crew was told not to perform a maneuver that would have let them photograph the external tank from an overhead window.
More worrisome to mission managers, two debris shedding events were noticed in ascent photography and radar tracking. By Thursday, the second day of the simulated mission, photography and radar analysis had identified at least nine "debris events," including damage to tiles on the shuttle's right rear rocket pod and a possible impact around leading edge panel No. 6 on Discovery's right wing.
The Discovery astronauts, working in a flight simulator at the Johnson Space Center, spent flight day two inspecting the 44 reinforced carbon carbon - RCC - leading edge panels on both wings, along with the ship's RCC nose cap, using a new boom-mounted laser system attached to the end of the shuttle's robot arm.
Aside from the use of computer graphics and animation in place of actual video from space, this writer, observing from the mission control room at the Johnson Space Center, could not tell the difference between the simulation and an actual mission as lead flight director Paul Hill led his team through the complex inspection work.
But in what might be a surprise to at least some observers, mission managers overseeing Discovery's simulated docking with the international space station Friday afternoon - two full days after launch - still did not yet know for sure whether the RCC impact had caused any damage.
Data from the laser scanner used to inspect the leading edge Thursday was inconclusive, officials said today, and close-up, targeted inspections were to be simulated Saturday. In addition, photos of the shuttle's belly taken by the crew of the space station during Discovery's final approach earlier today, showed unusual white speckles across the black heat-shield tiles that now must be investigated.
Senior managers said the pace of the simulation gave a sense of how long it will take NASA and contractor engineers to collect the data they would need in an actual flight to determine whether or not the shuttle had been damaged during launch or if repairs might be needed.
"We know we have some warning signs, we know we had some different debris events, we know we had one of those events gave us an indication on a wing leading edge sensor," Shannon said late Thursday. "That doesn't tell you if you have damage or not, it tells you potentially you had a hit in that area.
"The thing is, we go from a lot of data that's pretty low fidelity - from the imagery, from all the ground stuff, the external tank camera and the radar stuff - it's not very good fidelity but it tells you hey, something was going on and it clues you in to the next stage, which is what we're doing now and you go look carefully.
"It's going to be a little frustrating because you say OK, maybe they've got something here, here and here but it's going to take a few days to collect the data to see what is there. ... This is extremely complex."
In a real flight, the mission management team would not expect to have an impact site fully characterized and understood until flight day six. That is when the MMT would have to decide whether a shuttle could return to Earth as is, whether repairs were needed or whether a crew might have to abandon ship and use the space station as a "safe haven."
"It's really going to take us until flight day six to get all the reports, all the data, do all the analysis and come to a conclusion," Hale said. "Other than being anxious to get the answer, that's OK."
This week's simulation is working through that analysis and decision-making timeline in exhaustive detail.
"I would characterize the process as extremely realistic," Shannon said. "The systems engineering and integration guys are tracking nine different debris cases, the data collection's going on, two of them could be fairly significant. ... It's such a great, real-time prep for us to get real problems coming down, crunching them through all the people, all new processes, all the debris assessment stuff, this is all new. ... Just going through this whole cycle is so valuable."
The simulation was scheduled to end Friday evening, but the mission management team planned to work through the weekend assessing the impact data and debating all of the options they could face in a real flight.
Asked about the deliberate pace of the post-launch analysis during a real flight, John Muratore, a senior shuttle manager at the Johnson Space Center, said "my impression is this is going to be high drama for 14 days."
NASA hopes to move Discovery to launch pad 39B at the Kennedy Space Center around March 25. The launch window opens May 15 and closes June 3. The next launch window opens July 12.
"I think we're in pretty good shape," Hale said Wednesday. "We're working a number of problems on the orbiter, but that is fairly typical. ... The real issues we've got, I don't think it's orbiter processing. I think we're within the box on orbiter processing on Discovery. The real issue we've got is getting closure to the engineering analysis.
"We have to have the engineering analysis complete that proves it's safe to fly before we can go fly. If that means go park Discovery at the beach for an extra month, then so be it. Now, I don't think it's going to come to that. But we have got to prove it's safe to fly before we light the fuse."
Second redesigned shuttle external tank to ship
NASA NEWS RELEASE
Posted: March 4, 2005
NASA will ship its second redesigned Space Shuttle External Tank Saturday, March 5, from Michoud Assembly Facility, near New Orleans, marking the first step toward final launch preparations for the launch of STS-121, possibly this summer. The mission, on the Space Shuttle Atlantis, is the second test flight of the Space Shuttle following the Columbia accident.
http://spaceflightnow.com/news/n0503/04sts121et/sts121tank.jpg
The external tank for STS-121 is moved to its shipment barge. Credit: Lockheed Martin
The tank, designated ET-121, rolled out on its transporter March 4 at NASA's Michoud Assembly Facility in New Orleans and loaded onto a covered barge for shipment to Kennedy Space Center. The trip from the Mississippi River Gulf of Mexico Outlet to Florida's Banana River, which pours into the Atlantic Ocean, usually takes four to five days.
The first redesigned tank, ET-120, was shipped from New Orleans to Kennedy Space Center in December 2004. It will launch NASA's STS-114 Return to Flight mission planned for May. It incorporated several safety improvements, including an improved bipod fitting that connects the tank to the Orbit; a video camera mounted on the liquid oxygen feed line to photograph liftoff; reversed bolts on the flange of the tank's mid-section and a new process for spraying the thermal protection required there; redesign of the bellow, or "joints" for movement, along the liquid oxygen feed line, the 70-foot pipe that feeds liquid oxygen to the Main Engines; and a more defined spray procedure on the longeron, a structural support for the tank's aft, orbiter attachment struts.
In addition to the ET-120 modifications, NASA's second redesigned tank has been outfitted with temperature sensors and accelerometers, used to measure vibration, which will gather information about how it performs during flight.
Temperature sensors will be mounted on the tank's two forward "bipods." Each tank has two bipod fittings that connect the tank to the Orbiter at the Shuttle's two forward attachment struts. These sensors will monitor the temperature of the bipod web, the flat section of the bipod located between the fitting and the attachment plate.
There also will be seven accelerometers on the tank. Three will be located in the intertank, the Tank's midsection, near the bipods, to measure any vibration caused by changes in the aerodynamic load, or stress. The other four accelerometers will be located in the cable tray of liquid oxygen protuberance air load ramps and will be used to determine whether there is need for the ramps in future tank modifications.
"The instrumentation on ET-121 will confirm what our computer models tell us happens during launch and ascent," said Sandy Coleman, manager of the External Tank Project, an element of the Space Shuttle Propulsion Office at NASA's Marshall Space Flight Center in Huntsville, Ala. "Though computer models are invaluable, the information gained from an actual launch will give us an even better picture."
http://spaceflightnow.com/news/n0503/04sts121et/sts121tankload.jpg
The STS-121 external tank is loaded into its shipment barge. Credit: Lockheed Martin
During a launch, the External Tank delivers 535,000 gallons of liquid hydrogen and oxygen propellants to the three Main Engines, which power the Shuttle to orbit. The Tank is covered by a polyurethane-like foam that insulates the propellants, keeps ice from forming on the Tank's exterior and protects its aluminum skin from aerodynamic heat during ascent. The Tank -- the largest element of the Shuttle system -- measures 27.6 feet wide and 154 feet tall and is the only Shuttle component that cannot be reused. The other elements include the Orbiter, the twin Solid Rocket Boosters, each consisting of four solid rocket motor segments, and the three Main Engines.
The seven-member crew of the STS-114 Return to Flight mission to the International Space Station in May is the first step in realizing the Vision for Space Exploration, which calls for a stepping stone strategy of human and robotic missions to achieve new exploration goals. The Shuttle will be used to complete assembly of the International Space Station, a vital research platform for human endurance in space and a test bed for technologies and techniques that will enable longer journeys to the Moon, Mars and beyond.
The Space Shuttle Propulsion Office at the Marshall Center manages the Tank project. Lockheed Martin Space Systems Co., in New Orleans, is the primary contractor.
Tuesday, March 29
Shuttle Discovery leaves hangar on road to launch
Space shuttle Discovery emerged from its space-age garage at the Kennedy Space Center at 2 a.m. EST (0700 GMT) this morning for the quarter-mile move to the 52-story Vehicle Assembly Building where the ship will be mated with an external fuel tank and twin solid rocket boosters over the next few days. Discovery will return the shuttle program to flight with its launch now targeted for mid-May.
Misson Status:
http://spaceflightnow.com/shuttle/sts114/status.html
NASA Return To Flight homepage:
http://www1.nasa.gov/returntoflight/main/index.html
NASA Press Release:
Discovery Takes First Step Toward Launch Pad
http://www1.nasa.gov/images/content/111852main_rollover_full.jpg
In the early morning hours of Tuesday, March 29, Discovery rolled over from the Orbiter Processing Facility to the Vehicle Assembly Building (VAB) at NASA's Kennedy Space Center. There it will be attached to its redesigned External Tank and twin Solid Rocket Boosters.
On Monday, April 4, Discovery begins its eight hour journey to launch pad 39B. Discovery's mission, STS-114, is targeted for launch in May.
"This is a tremendous accomplishment for the Space Shuttle Program," said Bill Parsons, Space Shuttle Program Manager. "This effort has taken a talented team dedicated to meticulously preparing the vehicle and implementing all the modifications for a safe Return to Flight," he added.
Discovery seen from spac
SPACEFLIGHT NOW
Posted: April 6, 2005
http://spaceflightnow.com/shuttle/sts114/050406rolloutiss/issrollout.jpg
International Space Station commander Leroy Chiao spotted Discovery from 225 miles above Earth today and snapped this photograph of the shuttle as it was being rolled from the Vehicle Assembly Building to launch pad 39B. Credit: NASA, enhanced by William Harwood.
Space shuttle Discovery arrives at launch pad
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
April 7, 2005
The shuttle Discovery has been hauled to launch pad 39B at the Kennedy Space Center, the first shuttle "rollout" since Columbia's ill-fated mission and a major milestone on the road to resuming shuttle flights in May.
The glacial, 1-mph trip to the launch pad began at 2:04:36 p.m. EDT (1804:36 GMT) Wednesday after a brief delay to discuss a hairline crack seen in the insulation covering Discovery's external fuel tank.
Engineers decided the two-inch-long crack did not require repair and a powerful Apollo-era crawler-transporter slowly hauled the shuttle and its mobile launch platform out of the cavernous Vehicle Assembly Building and into a brilliant spring sky.
Looking on were scores of space center employees, reporters, tourists aboard visitor's center buses and even the crew of the international space station, which passed almost directly overhead around 4:30 p.m. EDT. If all goes well, Discovery will dock with the station two days after launch on the 114th shuttle mission.
The move was interrupted just after nightfall when the shuttle reached the launch pad ramp. A problem with the system that keeps Discovery and mobile launch platform level during ascent up the incline experienced a faulty electronics card that had to be replaced. Rollout resumed a few hours later and Discovery's launch platform finally came to rest atop the pad pedestals at 1:16 a.m. EDT this morning.
Rollout originally was planned for late March, but the 4.2-mile trip was held up because of minor processing snags and technical issues that used up most of the contingency time built into the schedule to handle unexpected problems at the pad.
By rolling to the pad Wednesday, NASA can still, in theory, launch Discovery as early as May 15. But any additional problems almost certainly will delay launch. NASA has until June 3 to get Discovery off the ground on the first post-Columbia mission or the flight will be delayed to at least July 13, the next available daylight launch opportunity to the international space station.
As engineers in Florida were preparing Discovery for its long-awaited trip to the pad, the shuttle's crew and flight controllers at the Johnson Space Center in Houston were practicing re-entry procedures in a series of morning simulations riddled with mock failures and problems.
Speaking to reporters in mission control, ascent-entry flight director LeRoy Cain said Discovery's rollout was "an important milestone because it's such a collaborative effort to get to this point."
"What I see here is the people and the machinery coming together," he said. "This is a point in time where we begin to converge all of the people with all of the machinery and we move toward a common goal of launching."
Mission commander Eileen Collins said "it's a great sight to see Discovery rolling out to the launch pad. We know we're getting close."
While some outside observers have questioned whether NASA has done enough to fully implement safety recommendations made in the wake of the Columbia disaster, Cain said he has no doubts Discovery's crew and his flight control team are ready to go.
"I'm happy to be here, I'm excited to be here," he said. "We've worked very hard to get to this point. As I said earlier, this team is as ready as any team that I have seen when we're this many days from launch. I feel very confident in our abilities. I don't look at this as closure. I look at this as a new beginning. I consider ourselves ready to go to the next milestone for return to flight."
http://www1.nasa.gov/images/content/112528main_10b.jpg
NASA managers elated with shuttle fueling test
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: April 14, 2005
http://spaceflightnow.com/shuttle/sts114/050414tanking/discoverymidday.jpg
Space shuttle Discovery undergoes the special tanking test at pad 39B today. Credit: NASA TV/Spaceflight Now
The space shuttle's redesigned fuel tank sailed through a critical tanking test today, giving NASA managers increased confidence about launching Discovery on the first post-Columbia shuttle mission next month.
"We had an outstanding day today," said Wayne Hale, deputy manager of the shuttle program and chairman of NASA's mission management team. "After a long period of preparation, we're beginning to see our operations come to fruition.
"Today, we saw the newly modified external tank perform in an outstanding manner, we saw Discovery, which has gone through about three years of modifications, perform in an outstanding manner. And I have to also say the launch pad, the facility, which has gone through a major modification and extensive re-work, performed almost without flaw of any consequence."
Engineers pumped more than 500,000 gallons of supercold rocket fuel into Discovery's external tank today and then monitored the tank and the shuttle's systems down to the T-minus 31-second mark in a mock countdown. It was the first such tanking operation since Columbia's launch Jan. 16, 2003.
"Today's test was a major milestone," said launch director Mike Leinbach. "The next one is launch, and I'm really looking forward to that one."
The goals of the exercise were to give the launch team a chance to rehearse launch-day procedures, to verify the operation of critical launch pad systems and to demonstrate the tank's foam insulation could stand up to the stress of ultra-low temperatures without any major ice buildups.
During a debris verification review late last week, engineers discussed all possible sources of launch debris and retired all but three. The remaining open items involve the possibility of ice buildups around liquid oxygen feed line fittings near the so-called intertank region and pressurization line support fittings at the tip of the tank.
Post-Columbia impact testing shows even small pieces of ice, shaking off during launch, could cause serious damage to the shuttle's wing leading edge panels or its nose cap. Columbia was destroyed during re-entry Feb. 1, 2003, because of damage done by the impact of foam insulation during launch 16 days earlier. The insulation has now been been modified to minimize such debris shedding.
During today's test, ice buildups in the areas of concern were minimal and Hale said engineers are hopeful additional testing will close the remaining open items on the debris impact list.
"Ice is a biggie," Hale said. "One of the things we were very interested to look at today was the performance of the tank and ice growth on the tank," Hale said. "It performed very well, that is heartening news. But that is not all the story.
"We're doing some testing at Redstone Arsenal and other places regarding the potential for ice to shed off the tank during the ascent and we think there are a number of ways we're going to come to a good conclusion on that. But there is work remaining before us on that."
Discovery's launch window opens May 15 and closes June 3. The next window opens July 13. Leinbach said now that the tanking test is over, the pad processing flow is fairly standard with no other unusual tests. Between now and May 15, he said, the pad processing flow includes three days with no work planned.
"That's good news for us," he said. "Even better news for us is the test we performed today was the last non-standard activity we have at the launch pad. From here on out, it's standard pad processing. ... From here on out the rest of the pad flow is well understood. The fact that we have 'just' three days, if you want to say it that way, is not that bad."
But the time needed to resolve the remaining debris concerns forced NASA, in part, to delay a planned design certification review from Friday to next Tuesday. Another debris review is planned late next week and that information must then flow into NASA's flight readiness review process and to an independent panel charged with monitoring NASA's implementation of post-Columbia safety upgrades.
The review panel, headed by former Apollo astronaut Thomas Stafford and former shuttle commander Richard Covey, had hoped to present its final report to NASA's administrator a full month before launch to give the agency time to respond. That no longer appears plausible, but no firm dates have been set.
Hale would not speculate on when the work might get finished, saying only that NASA will not launch Discovery until it is safe to do so. But he was clearly encouraged by the results of today's tanking test.
"Both the debris verification review, the upcoming design certification review and the tanking test that we did today are key items on the way to being ready to go fly," he said. "We're not done yet, but these are key things that we needed to get accomplished. We're whittling down the to-do list of things we must do before we can we can certify the vehicle for flight readiness."
WEDNESDAY, APRIL 20, 2005
1956 GMT (3:56 p.m. EDT)
NEW DATE. NASA has set Sunday, May 22 as the new target launch date for space shuttle Discovery. Liftoff on that day will be approximately 1:03:49 p.m. EDT.
The one-week delay gives the space agency more time to complete final reviews and analysis in the run-up to the returning the shuttle fleet to flight.
We'll be updating all of our pages noted in the left-hand column of the Mission Status Center -- the flight plan, mission timelines, etc. -- to reflect the new launch date.
Da http://www.space.com/missionlaunches/050420_sts114_delay.html:
NASA Delays First Post-Columbia Launch
By Tariq Malik
Staff Writer
posted: 20 April 2005
05:47 pm ET
NASA has pushed back the date for its first space shuttle launch since the Columbia tragedy, delaying the flight one week to allow more time to complete much-needed paperwork and analyses, the space agency said Wednesday.
The Discovery orbiter and its STS-114 crew will launch no-earlier than May 22, shuttle program manager Bill Parsons said during a teleconference with reporters.
Previously, NASA officials had set the opening of Discovery’s launch window at May 15.
“The May 15 launch date was just a target and we always knew that we would have to revisit it,” Parsons said, adding that the shuttle will be launched when it is ready and not on a deadline.
The decision to reschedule Discovery’s launch window was already under discussion going into the mission’s design certification review meeting Tuesday, shuttle officials said
“It was obvious that … there was still a certain amount of analysis that needed to be done, of paperwork that needed to be done,” Parsons said.
The launch delay will allow time for NASA to complete a final debris verification review for Discovery’s flight next week and perform additional launch load analyses for the shuttle’s new orbital boom - a sensor-laden system that the STS-114 crew will use to scan their protective thermal protection tiles for damage.
Parsons said the additional time will also allow shuttle officials to deliver paperwork to the Stafford-Covey Return to Flight Task Force, an independent panel evaluating the space agency’s launch preparations. The task force postponed a late-March meeting due to the need for paperwork.
“We’re hoping to present to them on the 4th, 5th and 6th of May,” he said, adding that a flight readiness review meeting is scheduled for May 10.
A long effort
NASA has spent more than two years redesigning orbiter components and developing new tools and procedures to enhance space shuttle safety. Discovery’s STS-114 mission, a test flight, is NASA’s first opportunity to shakedown those modifications.
Among those changes – and one reason for Discovery’s initial May 15 to June 3 launch window - is a flight rule calling for a daylight launch and well-lit conditions external fuel tank separation.
Discovery only has one, five-minute period in which to lift off during each launch window day, though shuttle officials are confident that they step up to the task.
Wayne Hale, NASA’s deputy shuttle program manger, said that all of Discovery’s lighting restrictions will be aided by a new plan to reboost the space station in its orbit.
“It’s very fortunate that the orbital mechanics worked out that way,” Hale said of the station’s reboost, during which it will burn propellant. “It not only sets us up for the launch window, but also prepares the station for a Progress cargo rendezvous in June.”
More time for training
Discovery’s launch delay will give mission managers time to conduct one last simulation of the spaceflight and help lighten some of the training requirements for the STS-114 crew.
“Their [training] schedule was trending toward the higher side of what we allow,” Hale said. “Over the next few days the crew is going to take advantage of that extra time and get rest for launch.”
A dress rehearsal of Discovery’s launch countdown is slated for May 4.
Discovery will switch to new fuel tank before July blastoff
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
NASA managers today decided to stage a second tanking test next weekend or shortly after to troubleshoot problems with the shuttle Discovery's external fuel tank. The shuttle then will be hauled back to the Vehicle Assembly Building where engineers will attach the ship to a different set of boosters and a fresh external tank, officials said late today.
The shuttle will be returned to the launch pad in mid June for launch on the first post-Columbia mission around July 13, the opening of the next available space station launch window. But that date could slip if program managers order yet another tanking test after rollout to verify the performance of the new fuel tank.
NASA had hoped to launch Discovery on the first post-Columbia mission this month, but managers decided last week to delay the flight to the July window because of lingering concerns about the potential threat of ice on the external fuel tank and because of two problems that cropped up during a tanking test April 14.
The ice issue will be addressed by a heater around a liquid oxygen feedline bellows assembly similar to the one used to prevent ice buildups on the struts holding the nose of the shuttle to the external tank. The other two issues with the current tank are more subtle.
During the tanking test last month, two of four hydrogen sensors inside the tank, which are used to control the main engine shutdown sequence when the shuttle reaches space, failed to operate properly. Engineers have not yet pinned down what caused the problem, but all four must be operational for a launch to proceed.
In addition, a valve used to bleed off pressure in the hydrogen tank cycled more often than usual.
NASA managers spent the week debating a variety of processing options, including whether to stick with the current tank, whether to carry out one or two additional tanking tests and whether to swap out Discovery's tank and boosters for a set being assembled for the second post-Columbia flight (STS-121).
During a meeting late today, shuttle managers decided to implement a version of the latter scenario. Here is a timeline of major processing milestones (dates are approximate "no earlier than" targets and as such should be taken with a grin of salt):
05/15: Discovery's current tank is reloaded with a half-million gallons of rocket fuel to collect additional troubleshooting data on engine cutoff sensors, pressure relief system
05/28: Discovery is moved back to the Vehicle Assembly Building*
06/09: The orbiter is attached to the new booster/tank stack*
06/16: Discovery is moved back to pad 39B
07/13: Launch (assumes no additional tanking test)
* Discovery's rollback depends on when the new tank/booster stack is completed. Engineers hope to finish the work ahead of schedule, allowing them to move rollback up by several days or more.
Before Discovery is returned to the pad, engineers must decide whether an additional tanking test is needed to verify the performance of the new tank. Such a test would add several days to the processing schedule, pushing launch to around July 18. But if the test is not required, July 13 remains a viable launch target.
Discovery's launch window opens July 13 and closes July 31. The next launch window opens Sept. 9 and closes Sept. 24. A three-day window is available Nov. 8-10, a four-day window opens Jan. 4 and a lengthy window opens March 3 and closes March 19.
The launch window is based on an internal NASA requirement to launch at least the first two post-Columbia missions in daylight. But the issue is complicated by a requirement to also ensure the external tank separates half a world away in enough light to allow documentary photography.
To reach the space station, the shuttle must launch within five minutes of the moment Earth's rotation carries the launch pad into the plane of the station's orbit. When all of those requirements are met, along with others involving temperature constraints on the station, only a limited number of launch windows is available.
Engineers assess space shuttle launch schedule
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: May 4, 2005
The shuttle Discovery's crew strapped in today for a dress rehearsal countdown while program managers continued assessing what work needs to be done - and whether it can be completed in time - for a July 13 launch attempt.
http://spaceflightnow.com/shuttle/sts114/050504tcdt/tcdt.jpg
Space shuttle Discovery and her crew undergo a countdown rehearsal at pad 39B today. Credit: NASA TV/Spaceflight Now
In a traditional pre-flight milestone, commander Eileen Collins, pilot James Kelly, Stephen Robinson, Soichi Noguchi, Andrew Thomas, Wendy Lawrence and Charles Camarda donned their bright orange pressure suits and began climbing aboard Discovery shortly after 8 a.m. EDT (1200 GMT).
The countdown proceeded to the T-minus four-second mark when it ended with a simulated abort and main engine shut down at 11 a.m. EDT (1500 GMT). The test went smoothly and other than a minor communications glitch caused by a switch in the wrong position, no major problems were encountered.
"We had a very successful test. It felt to me like it was a real launch day," Collins told reporters this afternoon.The terminal countdown demonstration test, or TCDT, was already scheduled when NASA managers last week decided to delay the first post-Columbia mission from May 22 to no earlier than July 13, the opening of the next available space station launch window.
The launch delay was ordered because of concern about the possibility of ice buildups around a bellows assembly that allows the external tank's 17-inch-wide liquid oxygen line to flex slightly during fueling and launch. At issue is whether such ice could break off and damage the shuttle's heat-shield tiles or wing leading edge panels during ascent.
Wanting more time to assess the overall ice threat, and to install a heater on the liquid oxygen feedline bellows, program managers opted to delay launch. They also needed more time to troubleshoot two potentially serious problems that cropped up during a test April 14 when the external tank was loaded with a half-million gallons of supercold rocket fuel.
Two of four sensors in the liquid hydrogen tank that detect low levels and help control the engine shutdown sequence failed to operate properly. In addition, a pressure relief valve cycled more often than expected, indicating a problem of some sort in another system.
The feedline bellows heater assembly must be installed back at the Vehicle Assembly Building. But engineers have not yet decided when to move Discovery off its oceanside launch pad. They are considering another tanking test before rollback to gather additional data on the fuel depletion sensors and the relief valve.
They also are considering whether to move Discovery to a different set of boosters and a fresh external fuel tank currently being assembled for the second post-Columbia mission. The tank for that mission includes additional instrumentation not available in Discovery's current tank.
As of this writing, no such decisions have been made. But given the amount of work left to do, sources say it will be difficult to meet the July 13 launch target.
uffa, ancora a rimandare! :doh:
Another shuttle fueling test scheduled for Friday
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: May 19, 2005
NASA's launch team readied the shuttle Discovery today for a second fueling test Friday to help find the cause of two vexing problems that cropped up during a similar test in April. Other shuttle engineers, meanwhile, are assessing a clearance issue between the shuttle's main Ku-band TV antenna and a new on-orbit inspection boom that could delay the transmission of post-launch images of the ship's redesigned external tank.
As part of NASA's post-Columbia safety upgrade program, a 50-foot-long boom equipped with a television camera and laser sensors was installed on the right, or starboard, side of Discovery's cargo bay. The boom, picked up by the shuttle's robot arm in orbit, will be used to inspect Discovery's wing leading edge panels and heat shield tiles for any signs of launch impact damage.
Just in front of the orbiter boom sensor system, or OBSS, on the starboard sill of the cargo bay is the shuttle's Ku-band dish antenna, which is used to send high-speed data and television signals from the orbiter to the ground via NASA communications satellites.
Once in orbit, the antenna is deployed by swinging it out over the side of the cargo bay sill so it can lock onto and track the appropriate satellite. The antenna normally is deployed on the first day of a shuttle mission and in Discovery's case, flight controllers were counting on a flight day 1 deploy to downlink photographs of the external tank to look for signs of foam shedding.
But an analysis of clearances between the antenna and the OBSS shows that as the dish swings out, it could come within six tenths of an inch of the forward end of the boom, sources said. And that doesn't include the boom's insulation blankets. That tiny margin could shrink to just three tenths of an inch in orbit due to thermal issues. The shuttle Atlantis has a similar problem.
No one wants to risk damage to the Ku-band antenna, which is critical to the conduct of a mission, and NASA managers plan to meet next week to reassess the matter. But neither the boom nor the antenna can be easily repositioned. Barring a dramatic change, Discovery's crew could be forced to delay deployment of the Ku-band antenna until the second day of the mission, after the OBSS has been picked up by the robot arm.
While downlink of external tank video and photographs would be delayed by one day, officials said the overall impact would be relatively minor. And it would not affect transmission of data from new wing leading edge sensors using the shuttle's S-band radio system on flight day 1.
The clearance issue could have a more noticeable impact toward the end of the mission. Managers are debating two possible options: Stowing the antenna before Discovery undocks from the international space station or stowing the OBSS prior to undocking and then redeploying it the day before entry to re-stow the antenna. The first option would end normal television from the shuttle for the remainder of the flight while the second option would add complexity and additional failure scenarios.
Agency officials do not yet know why the clearance issue took so long to come to light. A contractor analysis earlier this year concluded there was more than an inch of clearance and as such, no problem. But measurements carried out by the astronaut office showed the actual clearance was half the earlier estimate.
The shuttle was designed so a robot arm could be installed on either side of the cargo bay. The OBSS was installed using those pre-existing mounting points. In that sense, the clearance problem has been there ever since the shuttle was built. But NASA never mounted anything on that side of the bay before the OBSS aboard Discovery.
The clearance issue is just one of several nagging problems facing the shuttle launch team as it readies Discovery for takeoff on the first post-Columbia mission. Launch currently is targeted for July 13, the opening of a window that extends through July 31.
Launch had been planned for May 22, but the flight slipped to the July window because of late-breaking concerns about ice formation on the external tank, and its potential for impact damage during ascent, and because of problems that were noticed during a tanking test April 14.
During that exercise, two of four fuel depletion sensors, also known as engine cutoff sensors, in the liquid hydrogen tank failed to operate properly. In addition, a hydrogen pressure relief valve cycled more often than normal.
The cutoff sensors are used to make sure the shuttle's three main engines do not run out of hydrogen while running, which would cause a potentially catastrophic oxygen-rich shut down. All four sensors are required to be operational for a countdown to proceed.
As for the relief valve, it operated within specification but its behavior was clearly unusual and engineers want to understand why. One possible explanation involves the operation of a new post-Columbia heater installed at the base of the bipod struts that hold the nose of the shuttle to the tank.
NASA managers earlier decided to move Discovery back to the Vehicle Assembly Building and attach it to a tank and booster set being prepared for the second post-Columbia flight. That tank will be equipped with a new heater to ease concerns about ice buildups on an oxygen feedline bellows assembly.
Still unresolved is what to do about potential ice buildups on brackets near the top of the tank. Engineers have suggested using infrared spotlights to prevent or minimize ice formation, but additional tests are required to determine the plan's feasibility.
In the meantime, NASA managers ordered a second tanking test Friday to collect additional data before Discovery is moved back to the Vehicle Assembly Building. The currently-installed bipod heaters will be on for part of the test and then turned off to find out whether the heaters influence the operation of the pressure relief valve.
Here is a tanking test timeline (all times in EDT):
May 19
08:00 p.m....Rotating service structure retraction
11:30 p.m....Final loading preps begin
May 20
02:30 a.m....Pad cleared of personnel
04:00 a.m....Mission management team meets for go/no-go decision
04:30 a.m....Begin a 1-hour built-in hold
05:30 a.m....Resume countdown
05:30 a.m....Begin propellant line chilldown (fueling begins)
08:30 a.m....Fueling complete; stable replenish mode begins
08:30 a.m....Begin a 1-hour 45-minute built-in hold
10:15 a.m....Resume countdown with bipod heater on
01:35 p.m....Countdown is stopped at T-minus 31-second mark
01:35 p.m....Recycle countdown to T-minus 20-minute mark
01:45 p.m....Resume countdown with bipod heater off
02:45 p.m....Final cutoff at T-minus 31-second mark
02:45 p.m....Begin propellant drain back and boiloff
May 21
03:00 p.m....Rotating service structure moved back around shuttle
The launch team plans to test fire one of Discovery's three auxiliary power units, which generates the ship's hydraulic power, on May 23. The next day - May 24 - the orbiter will be moved back to the Vehicle Assembly Building for attachment to the new tank and boosters on June 7.
Discovery's space station cargo is scheduled to be moved to launch pad 39B on June 9 with Discovery following suit on June 14. If all goes well, the shuttle will be ready for launch July 13 as currently planned.
But engineers are still debating whether to stage a third tanking test to make sure the new tank operates normally when loaded with a half-million gallons of supercold propellants. If a separate, stand-alone test is required it likely would be staged around June 22, setting the stage for a launch attempt around July 19. But some engineers have suggested extending Discovery's countdown and inserting a tanking test a few days before the July 13 launch target.
A decision on whether to stage a third tanking test is expected early next month.
NASA Chief to KSC: Shuttles' End is Coming
By Chris Kridler
FLORIDA TODAY
posted: 20 May 2005
03:57 pm ET
CAPE CANAVERAL, Fla. - New NASA administrator Mike Griffin, visiting Kennedy Space Center today, made it clear the shuttle would be replaced, and soon.
"I report to the president," he told journalists. "The president has said we’re retiring the orbiter by 2010, and that’s what we’re doing."
The agency should have a transition plan ready by summer’s end, he said, that would outline how much of the International Space Station might actually be finished by the time the shuttles are done.
As a replacement for the shuttles is built, some jobs inevitably will change at Kennedy Space Center, and some will be lost, he said.
"Not everyone will transition," he said. "One of the main issues with the orbiter is how much it takes to care and feed the fleet."
Griffin also spoke with employees, acknowledging that for some, the transition wouldn’t be fun. "You enter a period where you need to watch out for yourself, and you need to look out for new opportunities."
The space program has to evolve, he said. His goal is to narrow the gap between the end of the shuttles and the launching of the next ship.
"If it takes more than five years, then it does," Griffin said. "It will take what it takes."
He said this was one of several visits he has made to KSC over the years while working with rockets and shuttle payloads, and it’s "the greatest place in the world to be. Wish I could figure out a way to put NASA headquarters here."
NASA nixes third tanking test for shuttle Discovery
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: June 6, 2005
NASA managers today ruled out a third tanking test for the shuttle Discovery, keeping launch of the first post-Columbia mission on target for July 13. The launch window extends to July 31 and as of this writing, engineers have five days of contingency time in the launch processing schedule to handle unexpected problems between now and the opening of the window.
Space shuttle Discovery is lowered to the ground after being removed from its original external tank and solid rocket boosters. Credit: NASA-KSC
Still to come: final disposition of questions about the risk posed by ice debris during launch; a final report by the Stafford-Covey Return to Flight Task Group regarding NASA's implementation of post-Columbia safety upgrades; and a formal flight readiness review to clear Discovery for flight.
The debris verification review, which will quantify the threat posed by ice debris based on a flurry of recent tests and extensive analysis, is targeted for June 24, followed by the Stafford-Covey group's final meeting and the two-day flight readiness review, which will be held at the Kennedy Space Center.
Among the debris threats still on the table is the question of possible ice buildups around brackets near the top of the external tank.
Assuming no show stoppers emerge during the meetings later this month, commander Eileen Collins and her crew will fly to Kennedy July 9 for the start of the countdown to blastoff of the 114th shuttle mission. Liftoff July 13 is targeted for 3:51 p.m. EDT (1951 GMT).
NASA had hoped to launch Discovery in May, but problems cropped up during a fueling test April 14 that contributed to a decision to delay the flight to mid July. During that test, two of four liquid hydrogen fuel depletion sensors (also known as engine cutoff sensors) failed to operate properly and a pressure relief valve that helps maintain hydrogen tank pressurization in the final two minutes of the countdown cycled more often than usual.
At the same time, the ongoing ice debris verification review raised questions about potentially dangerous buildups of ice around a liquid oxygen feedline bellows assembly that could shake off during launch and damage the shuttle's fragile heat shield tiles or wing leading edge panels.
NASA managers ultimately decided to delay launch and to move Discovery to a different set of boosters and a modified external tank equipped with a heater on the feedline bellows to prevent ice formation. Engineers are still debating the threat posed by ice around brackets at the top of the tank.
The new tank also features an older-style single-screen diffuser, which injects a jet of helium gas into the hydrogen tank to help keep the supercold fuel circulating at the proper temperature. It also provides the pressurization needed after the tank is isolated from ground systems one minute 52 seconds prior to launch.
Engineers believe the unusual valve cycling during the April 14 tanking test was due to a newer style dual-screen diffuser. During the April 14 test and a second tanking test May 20, the valve cycled 13 times. Based on past experience, it was expected to cycle eight or nine times.
By switching back to the older single-screen diffuser, engineers are confident the problem will not recur during the launch countdown. But testing continues to make sure.
As for the engine cutoff sensors, NASA managers now believe the intermittent operation in April most likely was do to a wiring issue that was resolved during troubleshooting. The sensors worked properly during the May 20 tanking test and engineers believe the sensors in Discovery's new tank will behave normally as well.
Galleria del demating del Discovery stack:
http://spaceflightnow.com/shuttle/sts114/050603demate/01.html
ITS OFFICIAL! LAUNCH DATE SET FOR JULY 13TH
THURSDAY, JUNE 30, 2005
NASA has cleared the Space Shuttle to Return to Flight. After a two-day Flight Readiness Review meeting at NASA's Kennedy Space Center in Florida, senior managers approved a July 13 launch date for Discovery.
Commander Eileen Collins and her crew are scheduled to lift off at 3:51 p.m. EDT on the first U.S. space flight since the February 2003 loss of the Shuttle Columbia.
"After a vigorous, healthy discussion our team has come to a decision: we're ready to go," NASA Administrator Michael Griffin said after the meeting. "The past two and half years have resulted in significant improvements that have greatly reduced the risk of flying the Shuttle. But we should never lose sight of the fact that space flight is risky.
"The Discovery mission, designated STS-114, is a test flight," Griffin said, noting that astronauts will try out a host of new Space Shuttle safety enhancements. In addition, Discovery will carry 15 tons of supplies and replacement hardware to the International Space Station. July 13 is the beginning of three weeks of possible launch days that run through July 31.
NASA's Associate Administrator for Space Operations, William Readdy, chaired the Flight Readiness Review, the meeting that traditionally sets launch dates and assesses the Shuttle's fitness to fly.
"Today's decision is an important milestone in returning the Shuttle to service for the country. Our technical and engineering teams are continuing their in-depth preparations to ensure that Eileen and her crew have a successful mission," he said.
Da Space.com:
Shuttle Launch Set for July 13
By Tariq Malik
Staff Writer
posted: 30 June 2005
4:45 p.m. ET
NASA’s first space shuttle to fly since the Columbia disaster will launch as planned on July 13, shuttle officials said Thursday.
After more than two years of training and re-training, the seven astronauts of NASA’s STS-114 mission are now set to ride the space shuttle Discovery spaceward as soon as their 19-day launch window opens.
“We are currently go for launch on July 13,” said NASA chief Michael Griffin during a press conference at Kennedy Space Center in Cape Canaveral, Florida.
Griffin and other shuttle program and launch managers announced the decision after a two-day flight readiness review.
“It’s just an outstanding day to be this close to get the shuttle flying again,” said NASA launch director Michael Leinbach told reporters. “It’s a great, great feeling.”
NASA’s three remaining space shuttles have been grounded since Feb. 1, 2003, when the Columbia orbiter broke apart as it reentered the Earth’s atmosphere, killing its seven-astronaut crew. The orbiter's heat-resistant skin was damaged at liftoff by a chunk of external tank insulation foam, which punctured its left wing leading edge and allowed hot atmospheric gases to enter during reentry, investigators later found.
Earlier this week, an independent task group found that NASA was unable to meet three of the 15 recommendations Columbia investigators believed should be addressed before the agency launched its next shuttle flight. The task group said NASA is still unable to completely prevent orbiter damage from ice or foam debris at launch, and that its on-orbit shuttle repair techniques were still too nascent to be considered reliable.
Griffin and other NASA shuttle officials said the space agency has managed to lower those risks for Discovery’s flight.
Discovery’s STS-114 flight, commanded by veteran astronaut Eileen Collins, will culminate two and a half years of redesigns and modifications to enhance orbiter and external tank safety.
“We went literally from stem to stern on the vehicle…to make sure that we did come back smarter and surer of a safe result,” said Bill Parsons, NASA’s shuttle program manager, during the briefing.
Griffin said the he spent almost two hours speaking with Collins and her crew about the launch decision.
“The crew is go for launch, and they want us to be go for launch,” Griffin said. “They want to return to flight, but they don’t want us to rush to flight.”
NASA News release
LCD Timeline
Launch-3 Days (Sunday, July 10): Countdown begins at the T-43 hours (6 p.m.)
Launch-2 Days (Monday, July 11)
Remove mid-deck and flight-deck platforms (2 a.m.);
Complete preparation to load power reactant storage and distribution system (5 a.m.);
Activate and test navigational systems (7 a.m.);
Flight deck preliminary inspections complete (10 a.m.)
Enter first built-in hold at T-27 hours for four hours (10 a.m.)
Resume countdown (2 p.m.);
Begin loading of cryogenic reactants into Discovery's fuel cell storage tanks (3:30 p.m.)
Enter 4-hour built-in hold at T-19 hours (10 p.m.)
Launch-1 Day (Tuesday, July 12)
Resume countdown (2 a.m.);
Final preparations of Shuttle's three main engines for tanking and flight (2 a.m.);
Fill pad sound suppression system water tank (3 to 6 a.m.)
Enter planned hold at T-11 hours for 12 hours, 55 minutes (10 a.m.);
Begin star tracker functional checks (10:50 a.m.);
Move Rotating Service Structure to the park position (7 p.m.)
Resume countdown at T-11 hours (11 p.m.)
Launch Day (Wednesday, July 13)
Enter planned 2-hour built-in hold at T-6 hours (3:55 a.m.);
Verification of launch commit criteria prior to cryogenic loading of External Tank(ET)
Resume countdown (5:55 a.m.)
Begin load ET with 500,000 gallons of cryogenic propellants (approx. 6:05 to approx. 8:55 a.m.);
Final Inspection Team to launch pad
Enter planned 3-hour built-in hold at T-3 hours (8:55 a.m.);
Perform inertial measurement unit preflight calibration;
Align Merritt Island Launch Area tracking antennas
Resume countdown at T-3 hours (11:55 a.m.)
Crew departs Operations and Checkout Building for the pad (12 p.m.);
Crew entry into orbiter (approx. 12:30 p.m.);
Crew air-to-ground voice checks with Launch and Mission Control;
Close Discovery's crew hatch (about 1:35 p.m.)
Enter planned 10-minute hold at T-20 minutes (2:35 p.m.);
NASA Test Director conducts final launch team briefings; inertial measurement unit preflight alignments
Resume countdown at T-20 minutes (2:45 p.m.);
Transition the orbiter's onboard computers to launch configuration;
backup flight system to launch configuration
Enter estimated 40-minute hold at T-9 minutes (2:56 p.m.);
Launch director, Mission Management Team and NASA test director conduct final polls for go/no go to launch
Resume countdown at T-9 minutes (about 3:36 p.m.) (more likly resume at 3:42 to launch in plane)
Start automatic ground launch sequencer (T-9:00 minutes);
Retract orbiter crew access arm (T-7:30);
Ignition of three Shuttle main engines (T-6.6 seconds); ignition and liftoff (T-0)
STS-114 CREW & LAUNCH DAY ACTIVITIES (TV events (#)-times may vary)
Commander Eileen Collins; pilot James Kelly; payload commander Soichi Noguchi; mission specialists Stephen Robinson, Andrew Thomas, Wendy Lawrence, Charles Camarda
5:45 a.m. Crew wake up; 6:15 a.m.
Breakfast #10:15 a.m.
Crew snack #11:20 a.m.
Weather Briefing #11:20-11:50 a.m.
Don flight suits #12:00 p.m.
Depart for launch pad #12:30 p.m. Arrive at white room;
begin entering Shuttle #1:45 p.m.
Close crew hatch #3:51 p.m.
Launch
For NASA TV schedules, viewing and information on the Web, visit: http://www.nasa.gov/ntv
ChristinaAemiliana
10-08-2005, 13:13
Lo Shuttle atterra ma la Nasa sospende le missioni
La navicella dopo due settimane di timori è rientrata alla base militare di Edwards in California. I responsabili del programma: «Non possiamo prevedere quando l’uomo tornerà a volare»
10 Agosto 2005
di Maurizio Molinari
NEW YORK. Con alle spalle tredici giorni di test nello spazio il «Discovery» è atterrato ieri sulla pista della base aerea di Edwards, in California, portando a compimento la prima missione del programma Shuttle dopo il disastro del «Columbia», avvenuto due anni e mezzo fa.
Superati i timori di danni alle piastrelle termiche che proteggono la navetta grazie a tre passeggiate spaziali, la navicella comandata da Eileen Collins ha vissuto il suo ultimo brivido quando è entrata nell'atmosfera sopra le Isole Cook trovandosi obbligata da una forte tempesta a rinunciare all'arrivo in Florida di prima mattina per atterrare piuttosto a Edwards allorché in California era ancora buio.
Quando le ruote si sono fermate il centro di controllo ha salutato l'equipaggio con un «congratulazioni per il volo spettacolare, benvenuti a casa, amici» ed il comandante ha replicato: «Siamo felici di essere tornati, grazie a tutti per il lavoro ben fatto».
Il top manager del programma Shuttle, Bill Parson, ha ricordato gli astronauti (sei americani ed un israeliano) che morirono nell'ultima missione: «Portando a casa in salvo il Discovery oggi abbiamo reso omaggio all'equipaggio del Columbia».
Due ore dopo è stata Eileen Collins a prendere la parola, con gli altri sei membri dell'equipaggio (tutti americani tranne un giapponese) schierati alle sue spalle, definendo «fantastiche» le condizioni del «Discovery». Ed il presidente George W. Bush da Crawford ha parlato di un «grande risultato». Ma durante le ultime ore il personale tecnico della Nasa era stato con il fiato sospeso: «C'è stata ansia durante l'intera giornata - sono state le parole di LeRoy Cain, direttore dei voli - ed abbiamo avuto un paio di anomalie che si sono rivelate insignificanti».
Alla fine tutti i riflettori sono stati per il comandante. Cinquantanove anni, nata a Elmira, New York, ex colonnello dell'Us Air Force ed appassionata di golf, letture e fotografia è stata proprio Eileen Collins la protagonista del volo a cui la Nasa ha affidato il salvataggio del programma Shuttle. Lei ha risposto alla sfida unendo le capacità operative e l'esperienza dello spazio - nel 1993 comandò proprio il «Columbia» diventando la prima donna ad aver mai pilotato uno Shuttle fuori dall'atmosfera - ad una notevole abilità nella comunicazione. Quando dopo il decollo si scoprì che sotto la pancia del «Discovery» qualche piastrella termica poteva essersi staccata è stata lei a rassicurare l'America, offrendo in diretta tv il sorriso casalingo unito ad un forte carattere. E quando alla vigilia della terza passeggiata spaziale è stato Bush a chiamarla per rendere omaggio al «coraggio di chi rischia per continuare l'esplorazione dello spazio» è stata ancora lei a ringraziare cordialmente, facendo sapere che era arrivato il momento di rimettersi a lavoro.
La madre, Rose Marie Collins, non ha mai dubitato che Eileen ce l'avrebbe fatta a riportare sulla Terra la navicella ed allontanare l'incubo di una nuova tragedia. Ed allorché la Nasa ha comunicato che l'atterraggio sarebbe avvenuto in California, mentre i grandi network commentavano il cambiamento di programma con allarme, la signora Rose Marie spiegava tranquillamente alle agenzie di stampa che lo Shuttle era in una botte di ferro perché la figlia conosceva «a memoria» la pista di Edwards per esserci atterrata più volte ai comandi di aerei cargo C-141 quando vestiva la divisa dell'Us Air Force.
A Rochester, dove Marie Rose vive, tutti conoscono bene quanto sia saldo il rapporto fra madre e figlia, confermato da uno scambio di email avvenuto tre giorni fa. Marie Rose scrisse «figlia mia ti penso sempre, augurandoti il meglio» e Eileen rispose «I love you, too, Mom», anche io ti voglio bene mamma. Non è tuttavia detto che la missione portata a compimento riesca ad allontanare ogni nube dallo Shuttle. «Non sono ancora in grado di affermare quando una navicella potrà tornare a volare» ha affermato Michael Griffin, amministratore della Nasa, confermando la decisione di sospendere la partenza di «Atlantis» in settembre fino a quando non si riuscirà a porre rimedio al tallone d'Achille che condannò il «Columbia» ed ha fatto temere anche per il «Discovery»: il distacco di parti di materiale isolante dalla rivestitura del contenitore di carburante durante il decollo.
http://www.lastampa.it/redazione/Esteri/shuttle.asp
Certo, non è una rivista scientifica ma è meglio di niente! L'ho letto a colazione e visto che c'è anche online tanto vale aggiungerlo...:D
NASA successfully completes shuttle SRB test firing
NASA NEWS RELEASE
Posted: August 16, 2005
NASA's Space Shuttle program successfully fired its first Production Rate Motor Tuesday, Aug. 16, at a Utah test facility. The two-minute static, or stationary, firing of the rocket motor was performed at ATK Thiokol Inc., an Alliant Techsystems company, in Promontory, north of Salt Lake City.
http://spaceflightnow.com/news/n0508/16srbtest/srbtest.jpg
A two-minute static firing of the shuttle program's first Production Rate Motor was successfully tested Aug. 16. Credit: ATK Thiokol
Download a larger image here (http://www.nasa.gov/centers/marshall/images/content/125359main_167265_04_2000x1369.jpg)
The firing of the Production Rate Motor was one of several annual tests conducted by the Reusable Solid Rocket Motor Project Office at NASA's Marshall Space Flight Center in Huntsville, Ala., to qualify any proposed changes to the rocket motor and to guarantee that new materials meet safety requirements. These annual tests closely replicate a Space Shuttle launch.
The Aug. 16 test demonstrated process, material and design changes made to the Reusable Solid Rocket Motors produced during the past two years. The motor firing also will allow NASA to further evaluate the performance of new sensors that read and retain detailed information -- much faster than instruments now used -- on pressures generated in the motor during a Shuttle launch.
"Testing such as this is important to ensure continued quality and performance," said Jody Singer, manager of the Reusable Solid Rocket Motor Project, part of the Space Shuttle Propulsion Office at the Marshall Center.
The test satisfied 48 objectives, including the evaluation of new sensors, or Intelligent Pressure Transducers. Produced by Stellar Technology, Inc. of Amherst, N.Y., the transducers also were tested earlier this year on a modified motor at the Marshall Center.
In addition to evaluating the performance of the new sensors, the test also monitored an operational pressure transducer recently qualified for flight and flown on STS-114: Space Shuttle Return to Flight launched July 26. These transducers, also made by Stellar Technology, help determine the time of separation of the Solid Rocket Boosters from the Orbiter.
The Production Rate Motor test also will allow NASA and ATK Thiokol engineers to further examine a more environmentally friendly insulation material and to gather information on a pressure-sensitive adhesive that may soon be used on the motor's joints.
Another objective of the test was to assess the performance of the propellant bore -- the hole down the middle -- of the rocket motor. When a motor is ignited, a controlled burn begins down its middle, creating the motor's thrust. The test results will show how motors react during the first few seconds following ignition and provide engineers more information on the firing stability of motors -- crucial information for human spaceflight.
Additionally, a powerful X-ray was used during the test to scrutinize how the motor nozzle performs during launch and ascent.
Static firings are part of the ongoing verification of components, materials and manufacturing processes required by the Space Shuttle program.
Test data will be analyzed and the results for each objective provided in a final report. Following the test, the motor's metal casings and its nozzle components will be refurbished for reuse.
ATK Thiokol manufactures the Shuttle's Solid Rocket Motor. The Shuttle's Reusable Solid Rocket Motor is the largest solid rocket motor ever flown, the only one rated for human flight and the first designed for reuse. It is the primary component of the Shuttle's twin Solid Rocket Boosters. These solid propellant rockets take the Shuttle to an altitude of 28 miles at a speed of 3,094 mph before they separate and fall into the ocean to be retrieved, then refurbished and prepared for another flight.
Next shuttle launch: March 2006
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: August 18, 2005
As expected, NASA managers today announced the next space shuttle flight will be delayed until at least next March to give engineers time to fix the external tank foam insulation problems that marred shuttle Discovery's launch last month.
At the same time, NASA Administrator Michael Griffin said he welcomed highly critical observations included in the final report of the Stafford-Covey Return to Flight Task Group, an advisory panel charged with assessing the agency's implementation of post-Columbia safety recommendations.
In a strongly worded "minority report," seven of the task group's 26 members blasted NASA's management of the post-Columbia shuttle program, blaming poor leadership for ongoing, pervasive "cultural" problems and an erosion of engineering rigor that raise questions about the agency's willingness to fly without a thorough understanding of the risks involved.
Griffin told reporters today that he asked panel chairmen Thomas Stafford and Richard Covey to include the group's observations in the task group's final report, "because frankly, I think we would do a disservice to ourselves and to our stakeholders and, frankly, to the taxpayers by creating an appearance that we do not wish to hear what people have to say if it should be negative."
"I think we do ourselves proud when we take all the comments that are given, we study them, we evaluate and we investigate them and we decide which ones make sense to us and that we wish to move forward on and which ones where we don't think the advisers got it right. I think that's the proper way to treat advice.
"I have conferred with the folks as recently as yesterday who provided those comments to us and I believe they fully understand the spirit of openness and honest acceptance that we're trying to convey to their issues."
But Griffin, as he has done on earlier occasions, made it clear it's up to NASA managers, not an advisory panel, to decide how the civil space program should be conducted.
"I've tried to put out a message on a number of occasions that NASA line management is in charge of the civil space program," Griffin said. "NASA will decide what to do with the shuttle and other issues. So we are accountable and responsible for what we do here in the civil space program.
"Advisory groups advise. We welcome the advice because it is very hard, when you're immersed in the day to day struggle to figure out the right thing, do the right thing and make the hard decisions, it's very hard to pull back and look at things from a big picture perspective. And so NASA often uses knowledgeable but external advisers to help us shape our decision making.
"But at the end of the day, those groups are not accountable and not responsible for what they suggest," Griffin said. "They provide information that we use to evaluate our course of action and that's what we will do with the Stafford-Covey task group report or any other report we commission."
Bill Gerstenmaier, newly appointed head of space operations at NASA headquarters, said the decision to push the next shuttle flight back to the March time frame was unavoidable given the work needed to fix the external tank foam shedding problem.
Because of a NASA-imposed requirement to launch the next flight in daylight, and to ensure the tank is jettisoned in daylight to permit photo documentation, NASA only had two launch windows left this year: Sept. 22-25 and Nov. 7-10. Another brief window was available Jan. 4-7, 2006.
"The last time I talked to you, I said September was pretty unlikely from a launch opportunities standpoint," Gerstenmaier said today. "We then looked at November and looked at January and kind of from an overall standpoint, we think really March 4 is kind of the time frame that we're looking at."
The target window opens March 4 and closes March 19. Engineers are hopeful the opening can be moved up one day, to 3:46 p.m. March 3, but that remains to be seen. The next window opens May 3 and runs through May 22 and the window after that runs from June 30 to July 19.
The new launch target "was driven by a variety of reasons," Gerstenmaier said. "One was the foam investigation, it looks like we're going to have to do some repair at Michoud (La.) on the tanks and then that will kind of pushes us into the first of the year."
Engineers still don't know what caused a large piece of foam to separate from a so-called "PAL ramp" on Discovery's external tank. But NASA now plans to ship the next tanks in the launch sequence back to Lockheed Martin's Michoud Assembly Facility near New Orleans where the PAL ramps likely will be removed and then rebuilt from scratch.
One benefit of the launch delay is that NASA can now use Discovery for the next mission instead of Atlantis as originally planned. The original plan called for Atlantis to be used for the second and third post-Columbia missions, in large part because Atlantis is lighter than Discovery and the third payload is made up of heavy solar array components.
"Now we can switch the launch order," Gerstenmaier said. "Instead of going Atlantis-Atlantis and having to turn that same vehicle around, we can now go Discovery, Atlantis and then back to Discovery and that's a much better overall flight sequence."
The foam problems driving the launch delay were an unexpected and embarrassing setback for NASA. The agency spent two-and-a-half years recovering from the Columbia disaster, addressing the issue of foam debris shedding and beefing up safety across the board.
Despite the foam problems and the critical nature of the Stafford-Covey minority report, Griffin expressed confidence in the shuttle program's management.
"Let me address the more important question of is there some crisis in confidence. No, there's not," Griffin said. "There may be, there may very well be, in accordance with the comments made in the Stafford-Covey report, some issues that we need to address regarding engineering process and engineer management, engineering discipline, those sorts of things.
"We've worked hard at NASA over the last two-and-a-half years to improve that situation that led to the loss of Columbia. But we don't suppose that we're done and one of the reasons why I was very receptive to the minority report was because we can't get done unless we're willing to listen to all of the hard truths. So we're going to be looking at our engineering processes.
"But let me illustrate what I see. For good or ill - and obviously it was for ill - we in NASA didn't look in detail at foam shedding from the tank for 113 flights. And shame on us. Absolutely, everyone in and out of NASA learned a lesson, I hope, about that. And that is an incident, that is a process that will be examined in textbooks for years to come. We flew 113 flights without seriously addressing the issue of how much foam was coming off the tank, why, where and what it was doing.
"OK. So on the first flight after being hit very hard, as hard as an agency can be hit by a mistake with the loss of seven lives ... on the first flight after we started really paying attention to the foam, almost everything we did worked. There are, I think, five areas where it didn't work right. And one of them with the PAL ramp foam was a big piece and it was very embarrassing. But ... almost everything did work right.
"So do I have a crisis of confidence in the team that made almost every thing work right? Of course not," Griffin said. "We're going to take the data and see where it leads us and we're going to fix those things that we didn't get right. But In a very important sense, this was the first try that the tank team, shuttle team, the NASA team ever really made to reduce the foam shedding to a minimal and acceptable level. I think they did pretty darn well for the first try. And that's how I'd like people to view it."
NASA plans to resume work at Michoud Assembly Facility
NASA NEWS RELEASE
Posted: September 17, 2005
Recovery efforts at NASA's Michoud Assembly Facility in New Orleans are progressing better than originally anticipated, almost three weeks after Hurricane Katrina struck. Power has been restored to the entire complex where space shuttle external fuel tanks are made. Temporary repairs have been made to damaged buildings.
Due to the progress, the Space Shuttle program has decided to keep tank work at Michoud. The program had explored the option of moving some tank work to NASA's Kennedy Space Center, Fla. Officials determined that by the time Kennedy's facilities were outfitted to do tank work, Michoud would already be operational. The agency is now assessing the work force needed to start and maintain minimal operations at Michoud. The main priority will be to ensure temporary housing for NASA civil servants and contractors whose homes were destroyed by Katrina.
Preparations are also under way to ship two external tanks from Kennedy back to Michoud by barge. External tank #120 is expected to arrive at Michoud in early October. It will be examined and portions of it dissected to better understand why foam came off during Space Shuttle Discovery's launch last July. External tank #119 will be sent back to Michoud in late October.
NASA is still working to contact 76 of more than 2,000 Michoud employees. The toll free phone number for employees to check in and for help locating employees who work at either Michoud or the Stennis Space Center, Miss., is: 877/470-5240
NASA has a public Web site to convey important contact information for NASA employees and contractors impacted by Katrina and for general public information at: http://www.nasa.gov/eoc
NASA also can take email inquiries from the public about general storm recovery activities. Use "Assistance -- Katrina" in the subject line, and send to: public-inquiries@hq.nasa.gov
Da Space.com (http://space.com/missionlaunches/ft_051001_et_fixes.html):
NASA Devises Shuttle External Tank Foam Fix
By Todd Halvorson
FLORIDA TODAY
posted: 1 October 2005
12:35 p.m. ET
CAPE CANAVERAL - NASA has a plan to fix its problem-plagued external fuel tanks, and the agency is studying the possibility of launching its next two shuttle missions in May and July.
NASA aims to replace an external tank foam ramp that shed a one-pound piece of insulation on the agency's first post-Columbia mission, prompting managers to put future flights on hold.
NASA shuttle chief Wayne Hale met with managers Thursday and asked them to determine what it would take to launch a second test flight in May and an International Space Station assembly mission in July.
Hale "was very straight-forward in saying, 'Look, these are not launch dates, but I just want you guys to come back and tell me what it would take to get there, if we can get there,' " said Kyle Herring, a spokesman for NASA's Johnson Space Center in Houston.
NASA's next mission officially is targeted for a March launch. But foam insulation problems and hurricane damage to agency facilities have made that all but impossible.
"I think that May would be the earliest, based on two hurricanes that not only caused damage at some of the facilities but also displaced the work force," Herring said.
Hurricane Katrina damaged NASA's Stennis Space Center in Bay St. Louis, Miss., and Michoud Assembly Facility in New Orleans. The agency estimates its repair and recovery costs will be about $1.1 billion.
Shuttle engines are tested at Stennis. Tanks are made at the Louisiana factory. Hurricane Rita forced NASA to close JSC last week, but no serious damage was done.
Katrina destroyed or damaged the homes of many of the 3,500 NASA and contractor employees who work at Stennis and Michoud. Many still are living in temporary housing.
"The work force is the first and foremost priority -- making sure that they are safe, and that they are taken care of. At the same time, a lot of those people who are affected are also motivated to get back to the business of flying space flights," Herring said.
"Even with the devastation to their lives, it's been kind of remarkable that they have stepped up and are back at work and are trying to balance that with their own personal issues."
The 2,000 workers at Louisiana plant will play a key role in fixing an external tank foam ramp that shed a one-pound
piece of insulation during Discovery's July 26 launch.
In a haunting reminder of the Columbia accident, the foam nearly hit the shuttle's right wing.
A 1.67-pound chunk of foam from Columbia's tank punched a hole in that shuttle's left wing, enabling hot gasses to rip the ship apart during atmospheric reentry.
The foam that doomed Columbia was designed to keep ice from building up on and potentially breaking off of an area where metal struts connect the tank to the nose of the orbiter.
A heater replaced the so-called bipod ramp as part of a $205 million post-Columbia effort to fix the tank.
On Discovery's flight, foam broke off a protuberance air load ramp that runs along the side of the 15-story tank. Its purpose: To ensure smooth airflow and minimize vibration around nearby pipes and cables.
NASA plans to remove the 37-foot ramp, replacing it with a new type of foam that will be applied with more exacting techniques designed to prevent shedding.
The area will be outfitted with instrumentation to better understand aerodynamic forces that could cause damage in flight.
Engineers think the change will work because the first 10 feet of the ramp was removed and replaced in that same fashion prior to Discovery's flight.
The work was done so that a safety modification could be made beneath the ramp, and no foam was shed from the reworked area.
The tank for NASA's next shuttle mission is being brought by barge back to the New Orleans factory and is expected to arrive there Sunday.
Engineers plan to use high-tech inspection gear to examine the ramp. Then they'll remove it and dissect it to try to learn more about the foam shedding phenomenon.
A return to Kennedy Space Center by January would put NASA in position to launch in May.
Published under license from FLORIDA TODAY. Copyright © 2005 FLORIDA TODAY. No portion of this material may be reproduced in any way without the written consent of FLORIDA TODAY.
Endeavour comes to life
NASA NEWS RELEASE
Posted: October 6, 2005
Engineers cheered as electricity coursed through Space Shuttle Endeavour today for the first time in two years. The powering of Endeavour signaled the end of the orbiter's major modification period at NASA's Kennedy Space Center, Fla.
http://www.spaceflightnow.com/news/n0510/06endeavour/endeavour.jpg
Carmen Prater, with United Space Alliance, works on the flight deck of the orbiter Endeavour. Credit: NASA-KSC
"Having three operational vehicles in the fleet affords the shuttle program great schedule flexibility, as we move toward flying safely and completing the international space station," said Space Shuttle Program Manager Wayne Hale.
Engineers and technicians spent 900,000 hours performing 124 modifications to the vehicle. These included recommended return to flight safety modifications, bonding more than 1,000 thermal protection system tiles and inspecting more than 150 miles of wiring. Eighty five of the modifications are complete and 39 are still underway.
Two of the more extensive modifications included the addition of the multi-functional electronic display system (glass cockpit), and the three-string global positioning system.
The glass cockpit is a new, full-color, flat-panel display system that improves interaction between the crew and orbiter. It provides easy-to-read graphics portraying key flight indicators like attitude display and mach speed. Endeavour was the last vehicle in the fleet to receive this system.
The three-string global positioning system will improve the shuttle's landing capability. It will allow Endeavour to make a landing at any runway long enough to handle the shuttle. The previous system only allowed for landings at military bases.
"When Endeavour was powered up, the team cheered at the completion of all of their hard work and accomplishments during the modification period," said Tassos Abadiotakis, Endeavour's vehicle manager. "The team worked tirelessly to ensure the vehicle progressed though the modification period on time and on budget."
Shuttle major modification periods are scheduled at regular intervals to enhance safety and performance, infuse new technology and allow thorough inspections of the airframe and wiring. This was the second of modification period performed entirely at Kennedy. Endeavour's previous modification was completed in March 1997.
Endeavour is beginning 10-12 months of launch processing and power-up testing for a future flight, possibly late next year.
Da http://www.space.com/spacenews/businessmonday_051010.html:
Revised NASA Shuttle Plan Includes Most Station Hardware
By Brian Berger
Staff Writer
NASA expects to fly 19 space shuttle missions between 2006 and the orbiter fleet’s planned retirement in 2010, completing by then a six-person International Space Station that would include most but not all of the hardware being built by the U.S. space agency’s international partners.
NASA’s revised space station plan, the result of several months of internal study, is slated for public release later in October. A preview of the so-called Shuttle/Station Configuration Options Team (S/SCOT) study provided to Space News shows that NASA intends to launch Europe’s Columbus laboratory module and the Japanese Experiment Module before retiring the shuttle. But NASA’s revised space station plan would eliminate the Russian Solar Power Platform and the Centrifuge Accommodation Module that the Japan Aerospace Exploration Agency had agreed to build for NASA under a barter agreement. Both the Russian power platform and the centrifuge module are designed to launch aboard the space shuttle.
NASA spokeswoman Debra Rahn said Oct. 6 that NASA’s international partners were briefed the previous week on the revised space station assembly plan. "We have initiated discussions with all the partners on the results of the Shuttle/Station Configuration Options Team study," Rahn said.
Bill Gerstenmaier, NASA associate administrator for space operations, held high-level consultations with senior officials of the space station partners in late September, Rahn said. Those telephone meetings are being followed by more formal bilateral sessions between NASA Administrator Mike Griffin and his international counterparts, she said.
Rahn said Griffin held the first of those meetings with the head of the Russian Federal Space Agency, Anatoly Perminov, while the two were at the Baikonur Cosmodrome in Kazakhstan for the Oct. 1 launch of a Soyuz capsule carrying a new two-person crew and U.S. space tourist Greg Olson to the space station. She said Griffin informed Perminov that NASA will not be able to launch the Russian Solar Power Platform.
Keiji Tachikawa, president of the Japan Aerospace Exploration Agency, was in Washington the week of Oct. 3 where he attended at least two receptions held in his honor and met with U.S. lawmakers. Rahn said Griffin did not meet with Tachikawa during his Washington visit because the two already have a formal meeting scheduled during the International Astronautical Congress in Fukuoka, Japan, the week of Oct. 17.
A formal Heads of Agency meeting involving Griffin and all of his space station counterparts is tentatively planned for December or January at a location still to be determined, Rahn said. The last such high-level space station meeting occurred in January in Montreal. At that meeting, NASA told the partners it planned to conduct 28 space shuttle flights by 2010, a manifest that included about 10 space station logistics and utilization flights but no mission to service the Hubble Space Telescope.
But not long after being sworn in as NASA administrator in April, Griffin began expressing doubts about the feasibility of the 28 flight manifest, even as he emphasized the agency’s resolve to retire the shuttle fleet before the end of 2010.
Griffin testified before Congress this spring that he thought NASA could eliminate all or nearly all of the logistics and utilization flights in the manifest and concentrate instead on using the shuttle solely for assembly flights requiring the orbiter’s payload bay.
According to the preview of the S/SCOT study results, NASA thinks it can accomplish 18 flights to the space station beginning with STS-121 — the second so-called Return to Flight mission it now hopes to launch in May — plus one mission to service Hubble, for a total of 19 flights. One of the assumptions underlying the new station assembly plan is that the shuttle orbiter fleet will be retired before Oct. 1, 2010, the start of the U.S. federal government’s new budget year.
Building the international space station is taking much longer than NASA and its partners ever expected. An assembly plan finalized in September 1997, one year before on-orbit construction actually began, envisioned completing the orbital outpost by late 2003.
The first piece of the space station, the Russian-built Zarya Control Module, was launched Nov. 20, 1998, aboard a Proton rocket. It was followed two weeks later by the U.S. Unity Node launched aboard NASA’s Space Shuttle Discovery. Space station assembly then hit a 19-month hiatus while Russia struggled to finish the next major component, the Zvezda Service Module.
The space shuttle fleet made 13 flights to the space station before the Space Shuttle Columbia’s fatal accident in February 2003. NASA has deployed no major hardware at the station since November 2002, when the Space Shuttle Endeavour delivered the outpost’s first U.S.-built solar arrays. NASA does not expect to resume space station assembly flights before July 2006, the agency’s current planning date for attempting its third post-Columbia flight. Although STS-121 is bound for the space station, the mission’s primary purpose is to validate changes made after the Columbia accident, not deliver major hardware to the station.
Endeavour comes to life
Bentornato in servizio Endeavour! ;)
(ovviamente non appena termineranno i rimanenti upgrades)
NASA hopeful tests can pave way to May shuttle launch
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: October 14, 2005
NASA managers are hopeful an exhaustive series of upcoming tests will help engineers pin down what caused foam insulation to fall off the shuttle Discovery's external tank during launch last July and, if all goes well, clear the way for another launch next May.
"We have not set an official launch date," shuttle program manager Wayne Hale told reporters today. "I want to make that very clear. The shuttle launch date for the next shuttle flight has been, in the lingo that the Eastern Range uses, 'indeterminate' since the foam incident on STS-114.
"We are, however, working toward technical solutions of our problems. ... We have a number of critical things ahead of us that we have to evaluate before we set an official launch schedule. However, based on the discussions that we had at the program board yesterday, it appears that the May launch window is something that we can begin to work toward now."
The launch window opens May 3 and closes May 23. The next window runs from July 1 through July 20 and the next window after that opens Aug. 28 and closes Sept. 14. The launch windows are based the shuttle's ability to reach the international space station and on a requirement to launch, and have the external tank separate, in daylight for photo documentation.
When Discovery blasted off in July, NASA had hoped to launch the second post-Columbia mission in September. But during the shuttle's climb to space, relatively large pieces of foam insulation fell away from five areas of the tank, including a potentially dangerous chunk from a so-called protuberance air load, or PAL, ramp. The PAL ramp is a long aerodynamic barrier made up of hand-sprayed foam designed to smooth the flow of supersonic air across an external cable tray and two pressurization lines.
In the wake of Discovery's launch on mission STS-114, shuttle flights were put on hold. NASA managers did not announce a new target date for the second post-Columbia flight beyond saying launches would be delayed until at least next March.
Then came Hurricane Katrina, which devastated New Orleans and the Gulf Coast. Lockheed Martin processes shuttle external tanks at its Michoud Assembly Facility near New Orleans and while damage was surprisingly slight, the 2,000-member workforce was seriously impacted.
Hale said today the storm and its aftermath set tank processing back at least three months. Some five hundred workers are back on the job at Michoud, but the full work force is not expected back on station until early December.
Even so, Hale said engineers are optimistic they will nail down the causes of the foam shedding in time to support a May launch.
"We are at the point where we believe we have an understanding of the parameters of those problems well enough in hand so we can get internal working schedules to the rest of our elements," Hale said. "Of course, any schedule we have is going to be critically dependent on the work that goes on at Michoud. And that's why the discussion of the work force and the work force returning to Michoud is critical to our scheduling effort. We believe we understand how that is going to take place over the next few weeks."
Richard Gilbrech led a "tiger team" of engineers charged with assessing the foam issue. He said today the team focused on three areas: the launch environment, that is, the forces acting on the foam during ascent; the materials used in the foam; and the way the foam was applied, removed for subsequent modifications and re-applied.
The launch environment was not a factor, the team concluded; the stresses acting on the tank were essentially the same as on previous flights. The materials used in the foam also were unchanged from previous flights with one major exception: the PAL ramp foam was made up of BX-265, a foam formulation slightly different from earlier tanks to comply with the latest environmental regulations.
"The third thing we looked at was processing, was there anything in the way this tank was processed that might give us a clue as to why we had lost foam," Gilbrech said. "The major finding we found was this tank was reworked to a level none of the other tanks prior had been, and we suspect that handling damage, or collateral damage - which is basically risk to the foam from technicians that have to be there and doing their work - we think is a potential contributor.
"I want to make it clear that we found no negligence on the part of the workers at the ET project. They were doing their work per procedure. It's just that we didn't really have an appreciation for the significance this handling damage could have in terms of foam loss."
The PAL ramp foam debris was the largest chunk to fall off Discovery's tank. Engineers believe it probably was the result of a combination of factors, including voids in the foam, possible cracks caused by thermal stresses in the ramp foam and the underlying foam it was applied to and inadvertent crush damage caused by engineers and technicians at Michoud working near the area during processing.
But Gilbrech said engineers do not believe "crushed foam alone could have been the cause of the foam coming off. We believe it was potentially a combination of (factors)."
Said Bill Gerstenmaier, chief of space operations at NASA headquarters: "I think it's really wrong to try to pick out one potential root cause and say that's the underlying problem or that's the smoking gun. Foam is very complicated. The failure mechanism is likely some combination of things and it's really wrong to try to pick out one and then try to focus all your efforts on that. That will actually set you 8up for more problems in the future."
The foam that doomed Columbia came off another aerodynamic ramp intended to keep ice from forming around the two bipod struts that attach the nose of the shuttle to the tank. The ramps were removed for Discovery's flight and replaced with heater strips. Surprisingly, foam popped away from the now-rampless bipod area during Discovery's launch.
As it turns out, engineers believe air inside the heater wiring channel condensed due to the ultra-low temperatures of the tank. The liquid nitrogen then changed back into a gas during launch and popped off overlying foam. Changes are planned to eliminate that threat in the future.
Another area of foam loss during Discovery's flight was from so-called ice-frost ramps, foam that covers the attachment fittings holding pressurization lines in place. Engineers may resolve that problem by drilling small holes in the foam, allowing pathways for trapped air to escape. This technique already is used elsewhere on the tank.
Foam also fell away from a flange area near the top of the hydrogen section of the tank and from the broad acreage foam covering most of the tank's exterior. Gilbrech said the intertank flange foam may have separated because of previous work in that area, but he did not specify what might be the cause of the acreage foam loss other than to say tests were being designed to resolve the issue.
The tank intended for the next shuttle flight is ET-119, which was recently shipped back to Michoud from the Kennedy Space Center. It currently is undergoing extensive inspections and X-ray analysis. The PAL ramps eventually will be removed, sliced every eighth of an inch to look for voids. They will be replaced using improved techniques with special care taken to ensure no inadvertent damage.
"That tank we have to do a number of things to, at the minimum removing and replacing the PAL ramps, re-working the bipod closeout area where we think the wire may have actually allowed cryogenic ingestion of air to condense in an area," Hale said. "We have a number of things that we've got to do before we're ready to do that work."
But Hale repeated that he is optimistic about making the May window.
"I think we have done enough analytical work to lay out a series of tests that over the next couple of months are going to give us a very clear and convincing understanding of why we lost the foam that we did on the external tank and allow us to design new techniques that will allow us to re-apply foam in areas in such a way that it won't come off even from some of these very complex interconnected causes. So we're addressing all those.
"What has taken us from July until October, if you want to think about it, is to come to that level of understanding of the work that's got to go forward to provide an engineering, rigorous understanding of the causes and solutions to foam coming off. What we're all here to report is a great deal of progress and a sense of optimism that we do have an understanding of the work that lies ahead of us."
Da NASA.gov:
Engineers are moving closer to resolving the problem of large foam insulation falling off space shuttle external fuel tanks during launch. A "tiger team" is making recommendations addressing the factors that may have contributed to foam loss when the space shuttle Discovery (STS-114) was launched in July.
The next shuttle mission is also on Discovery. It will be the second test flight in the Return to Flight sequence. At an Oct. 14 news conference at NASA's Johnson Space Center, Houston, space shuttle managers emphasized they have not set a specific launch date. NASA is using the May 3 to 23, 2006, launch window as a target for work to prepare Discovery for the mission.
EDIT: vabbe' lo aveva gia' postato GioFX.. ;)
Da Nasaspaceflight.com (http://www.nasaspaceflight.com/content/?id=3946):
NASA still aiming for 19 flights
10/27/2005 3:43:00 PM
By: Chris Bergin
A document acquired by this site has given revised details on the remaining flights of the Space Shuttle, with changes to the target launch dates and confirmation that Atlantis will be the first Orbiter to be retired in 2008.
Running through to 2009 - to give the STS (Space Transportation System) program a buffer zone to the targeted retirement in 2010 - the October 19th Flight Assignment Working Group (FAWG) Planning Manifest 05D-12 points to four flights in 2006.
Discovery's Return to Flight 3 mission STS-121 has been forwarded to earlier in the re-start of Shuttle operations to May 3, 2006, with Atlantis on her STS-300 stand-by rescue mission - if required - for June 15. This mission is at the mercy of testing and re-engineering work on External Tanks ET-119 and ET-120 - both currently at the Michoud Assembly Facility (MAF) in New Orleans.
Atlantis' primary launch processing is for STS-115, which is now due to launch on July 1. Atlantis' launch will see the re-start to ISS (International Space Station) assembly missions, adding the P3/P4 Truss to the outpost.
The youngest Orbiter in the fleet, Endeavour, joins the fleet in active flight operations on October 1 on STS-116, carrying SpaceHab and the P5 ISS element. This will be the first Shuttle mission to incorporate SSPTS (Station/Shuttle Power Transfer System) capability, allowing for flight duration to last 15 days.
A fourth mission is planned for 2006, with Atlantis once again in action on STS-117 with a target launch date of December 7. Atlantis will be carrying the S3/S4 ISS element.
On the manifest is six 2007 missions, starting with Endeavour on March 15 on STS-118, and ending with Atlantis on STS-124 on November 29. Atlantis' 14th of June STS-120 will mark the completion of the US Core of the ISS.
2008 sees another six launches, starting and ending with Endeavour's STS-121 on February 7 - ending with her STS-130 mission on December 4. This year will also mark the retirement of Atlantis. OV-104 would have been due for her Orbiter Major Maintenance (OMM) period in 2008, thus deciding her own retirement automatically, given the two years it takes to re-fit the Orbiters - a pointless exercise given the 2010 retirement target.
Three missions follow STS-130, with Discovery launching on STS-131 (March 19), Endeavour on STS-132 (May 14), and the final ever Space Shuttle mission coming with Discovery's STS-133 on August 20, 2009.
However, it needs to be stressed that all dates are flexible and open to changes, with the 2009 end date on the manifest more likely to give some breathing space should any delays during previous missions begin to accumulate over the years post STS-121.
Also worth noting is the current funding questions that have been raised of late.
NASA appears to have several options open to themselves, with a possibility of only flying missions that complete the US Core section of the ISS. That would bring the manifest down to eight flights, likely over the same time period to relax funding concerns.
What is expected to remain - although not listed on the manifest with a specific mission - is the Hubble Space Telescope servicing mission. That will not be part of the ISS assembly missions, given the different orbits of the ISS and Hubble. Sources note that mission will involve Endeavour, sometime in 2007/08.
Below is the list of launches noted on the latest manifest.
2006
STS-121 – Discovery – May 3
[STS-300 – Atlantis – June 15]
STS-115 – Atlantis – July 1
STS-116 – Endeavour – October 1
STS-117 – Atlantis – December 7
2007
STS-118 – Endeavour – March 15
STS-119 – Discovery – May 3
STS-120 – Atlantis – June 14
STS-122 – Endeavour – August 23
STS-123 – Discovery – October 11
STS-124 – Atlantis – November 29
2008
STS-125 – Endeavour – February 7
STS-126 – Discovery – April 3
STS-127 – Atlantis – May 22
STS-128 – Endeavour – July 3
STS-129 – Discovery – October 2
STS-130 – Endeavour – December 4
2009
STS-131 – Discovery – March 19
STS-132 – Endeavour – May 14
STS-133 – Discovery – August 20
.......
The Shuttle targeted launch dates were not for the next 7 flights however they will be in about 2 weeks if MSFC does good work.:
STS-121 (ULF1.1) OV-103 RTF NET May 3, 2006
STS-115 (12A) OV-104 Trusses P3/P4 NET July 1 (CSCS launch NET June 15
STS-116 (12A.1) OV-105 Space Hab, Truss P5 and ICC NET Oct. 01
STS-117 (13A) OV-104 Trusses S3/S4 NET Dec. 7
STS-118 (13A.1) OV-105 Space Hab and Truss S5 NET March 15, 2007
STS-119 (15A) OV-103 Truss S6 NET May 03
STS-120 (10A) OV-104 Node 2 NET June 14
NASA Likely To Fly Next Shuttle Sans Foam Ramp
By Brian Berger
Space News Staff Writer
posted: 2 December 2005
5:37 p.m. ET
WASHINGTON - NASA is leaning toward flying its next space shuttle mission without the protective foam ramp that broke away from Discovery's external tank during its July return to flight, according to a spokesman for the U.S. space agency.
Shuttle officials plan to meet again this month to evaluate the Protuberance Air Load (PAL) ramp issue and possibly reach a decision.
"The data from the ongoing engineering analysis on the PAL ramp seems to be pointing in the direction of not flying with the PAL ramp for STS-121," said NASA spokesman Allard Beutel, referring to Discovery's next mission, tentatively slated for May 2006.
Beutel said eliminating the PAL ramp would not in and of itself jeopardize the May launch opportunity, provided that wind tunnel testing now being planned for February confirms that it is safe to fly without the structure.
The PAL ramp was added to the external tank early the program's history to provide a windbreak for a cable tray that runs along the tank.
NASA Space Shuttle Program Manager Wayne Hale raised the possibility of eliminating the ramp from the STS-121 tank during a Nov. 22 update on work the agency has done to eliminate foam shedding.
"In the long run, we have decided we would like to remove this fairly large piece of foam, just eliminate the hazard that it might cause," Hale said at the press briefing. "We think we have a very strong case to be ready to take that ramp off by the third flight tank. Some folks believe we can accelerate that and potentially even remove it for the STS-121 tank."
Several days after that press briefing, Beutel said, shuttle officials received new data that showed that recently discovered PAL ramp cracks on tanks undergoing inspection ran deeper than previously thought. The new data persuaded Hale that NASA should give serious consideration to removing the PAL ramp before STS-121. Hale shared this view with colleagues in a Nov. 29 e-mail first reported by the Washington Post.
Hale's Nov. 29 e-mail said nothing about schedule impact, according to Beutel, but in a separate internal memo, written in early September in the immediate aftermath of Hurricane Katrina, Hale concluded that flying STS-121 without a PAL ramp was not a realistic option since all the testing and analysis involved would delay the mission until late 2006.
Beutel, however, said shuttle officials now think they can safely remove the PAL ramp without forfeiting the May launch window.
"They've had a couple more months to work this and after studying this problem up and down the chain they are thinking that the PAL ramp removal is more feasible than they did just a couple of months ago," Beutel said.
Wind tunnel tests are being planned for February to evaluate the aerodynamic effects of removing the PAL ramp. In order to preserve the May launch window, Beutel said NASA would go ahead and ship the tank assigned to STS-121 to Kennedy Space Center in Florida without a PAL ramp.
"If, and only if, our further testing and analysis supports flying without a PAL ramp is aerodynamically alright to do, as our preliminary analysis indicates it would be, then the May launch window is still possible to make," Beutel said. "If our new testing and analysis indicates we need the PAL ramp, we'll stop our shuttle processing, reassess and work the issue from there."
He said NASA would also continue to investigate new ways of applying PAL ramp foam to prevent cracking that could cause the structure to break off during launch.
Shuttle leaders decide to remove fuel tank foam ramps
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: December 15, 2005
NASA engineers and managers have recommended the removal of a protective foam air deflector from the shuttle's external tank to eliminate a major source of potentially dangerous launch debris, a top agency official said today. While NASA has not given up launching the next flight in May, additional work to implement and certify other changes required by the deflector removal could push the launch to later next summer.
Bill Gerstenmaier, NASA associate administrator for space operations, would not discuss possible launch targets during an afternoon teleconference with reporters, saying such talk was premature and put unnecessary "schedule pressure" on the team. Instead, he said, engineers were going to focus on thoroughly assessing the possible causes of foam shedding based on recent insights into cracks found in a tank slated for the flight after next.
"We're going to do the right thing and let the data drive us where we need to go," he said.
During a Program Requirements Control Board meeting at the Johnson Space Center in Houston today, engineers recommended removing the external tank protuberance air-load - PAL - ramps from the shuttle's external tank. Last month, shuttle program manager Wayne Hale said engineers did not believe NASA would be ready to launch a PAL-free tank until the third mission in the upcoming sequence.
But computer modeling now shows the structures the ramps were designed to protect - two pressurization lines, support brackets and a critical cable tray - are beefy enough to withstand any expected aerodynamic forces, or loads, they might encounter during ascent. Wind tunnel tests are planned for February to verify the results of the computer modeling.
But engineers are still assessing what changes will be required to so-called ice-frost ramps, areas of foam around the brackets supporting the pressurization lines that are intended to prevent ice formation before blastoff.
"Based on the data we've reviewed, we don't need to do any redesign of the cable tray or the press lines," Gerstenmeir said. "So there's no redesign of the basic bracketry or the basic tank structure. That all looks fine. We'll confirm that with the wind tunnel tests. The margins look very good in that region. ... So that's a very positive thing, it takes a lot of that work out of the critical path.
"From an overall standpoint, depending on what engineering solution gets picked (to address the ice-frost ramp issue), May is still very viable. Some of the other engineering solutions that would require a more detailed certification process of foam applications, etc., may move us somewhere else."
The shuttle's external tank is made up of a large hydrogen tank, a so-called intertank section and an upper oxygen tank. Gaseous hydrogen and oxygen, used to pressurize the tanks, are diverted from the propellants feeding the shuttle's main engines and routed up the tops of the respective tanks in externally mounted pipes. The pressurization lines run next to a long cable tray that carries electrical lines routing data and commands between the shuttle and various tank and booster subsystems.
When the shuttle was designed in the 1970s, engineers believed shock waves during the vehicle's transition to supersonic speeds could cause potentially catastrophic damage to the pressurization lines and/or the cable tray. As a result, the tank was equipped with two PAL ramps, one running along the upper section of the hydrogen tank and the other along the outside of the oxygen tank.
During Discovery's launching last July on shuttle mission STS-114 - the first post-Columbia flight - a one-pound chunk of foam ripped away from the hydrogen PAL ramp just after the ship's solid-fuel boosters were jettisoned two minutes and five seconds into flight.
Earlier this fall, Hale ordered all existing PAL ramps dissected and removed. Engineers were assessing new fabrication techniques as a possible solution when numerous small cracks were discovered prior to the removal of the PAL ramp of a tank slated for the third post-Columbia mission.
Engineers now believe the cracks almost certainly are related to the thermal stress the tank undergoes when it's loaded with super cold rocket fuel. The tank in question - ET-120 - originally was to be flown by Discovery last July and it was fueled for two pre-launch tests. The tank later was replaced for unrelated reasons, but the cracks could have been caused by thermal stress.
If that theory is correct, cracks would be a constant threat for shuttles that were fueled for launch and then delayed for other reasons. Whether similar cracks played a role in the foam loss experienced by Discovery's tank in July is an open question.
But given the small size of the cracks, the difficulty in detecting them at the launch pad and the lack of any on-pad repair procedures, NASA managers opted to forego attempting to fix the PAL ramps and to recommend their removal instead.
"They've done a tremendous job of chasing the cracks," Gerstenmaier said. "We saw the cracks in the non-destructive testing, in the X-rays and in the terahertz radar data. What they've done now is, they've carved out the cracks and they've followed the crack as it goes down into the foam and then they see the crack actually break into smaller cracks, into some delamination layers down internal to the foam. Then we see some of the cracks progress slightly underneath the cable tray, we see some of the cracks actually (branch) out into the acreage foam. So we know where the cracks are running.
"What we don't know is really why they're initiating. We have some theories. ... There are two different types of foam. There's the foam that's on the acreage of the tank that's about an inch thick and then we spray this PAL ramp foam on top of it. Those two types of foam have different thermal expansion coefficients, so we now have a math model of the stress field between those two foams as they chill down. That's a key driver. Where we put one type of foam on top of another type of foam, it causes that lower layer of foam to be colder, it's not as strong at cold temperatures so the cracks can initiate down there and then carry up into the upper piece of foam."
Gerstenmeir said a major unrsolved question is how temperature changes and tank pressurization interact to cause cracks. "Exactly how they fit together, we haven't had a chance to pull together," he said. But he provided a relatively detailed summary of how a crack might lead to foam shedding.
"The tank has a one-inch layer of foam all around and then the PAL ramp is about, probably an eight- to 10-inch foam layer (is) sprayed on top of that," he said. "What happens is that foam that's sprayed on top, it provides an insulating layer that allows that one-inch piece of foam to get cold through its entire length, so it is now cold from the surface of the tank all the way to the top of that one-inch layer of foam.
"The fact that that foam is cold, when it gets cold it loses some strength, or it's more brittle, and easier to crack. And then the fact that the foam on top is expanding at a different coefficient of thermal expansion, it causes a shear, or a stress layer, on top of that one-inch layer of foam as well as there's a shear layer, or a stress layer, down where the foam attaches to the tank.
"So then, that can cause a crack to initiate somewhere in that underlying one-inch piece of foam and then that crack can then propagate on up into the foam on top of it. If that crack goes all the way to the surface, that's where the outside air is, and it goes all the way down to the tank, then that provides a path for air to come in, liquefy in that lower region next to the tank."
As the super cold hydrogen in the tank is drained and the structure warms up, "that liquid air then expands, pushes out on the foam and can cause a large piece of foam to come off," Gerstenmaier said. "So that's kind of the theory we're looking at."
Removing the PAL ramp will eliminate the problem with differential contraction and expansion based on the use of two different types of foam. But engineers still must decide what will be needed to eliminate foam shedding around the ice-frost ramp brackets that support the pressurization lines.
"The ice frost ramp sticks under the cable tray a little bit and it sticks into that region where the PAL ramp was and we saw some cracking in that ice frost ramp right next to the cable tray, or actually maybe a little bit under the cable tray," Gerstenmaier said. "What we need to do is understand what caused that cracking and will it be prevented by just removing the PAL ramp? Do we need to do something in that area, do we need to put some kind of other foam over that (to prevent) ice formation in that area? That's the kind of work we need to go understand.
"The engineering teams have many solutions for that. We'll check some of those out analytically over the next couple of weeks, we'll pick an engineering solution, probably in the next week or two, then schedule a little bit of confirmation tests or analysis in the early part of January. And then if we need to make a physical fix on the tank by spraying foam, we would do that in the middle part of January to the later part of January and then we would ship the tank around the first part of February."
If that schedule holds up, NASA would have a theoretical shot at launching the shuttle Discovery in May. Because of a post-Columbia decision to launch at least the first two return-to-flight missions in daylight - and to ensure the external tank separates in daylight half a world away - NASA can only launch during relatively short "windows." The next three such launch windows are:
May 3-23
July 1-20
Aug. 28 to Sept. 14
Whatever engineers decide to do to Discovery's tank, they will also have to upgrade a tank for use in a possible emergency rescue mission. Assuming Discovery's flight goes well, that tank and shuttle then would be used for the next normal flight in the sequence.
The tank currently slated for use in that mission, ET-120, has so many small cracks, many of them penetrating all the way to the aluminum skin of the tank itself, it may make more sense to process another tank, ET-118, in its place. Gerstenmaier said today a second tank will, in fact, be ready in time to support Discovery's mission whenever it is cleared to fly.
Da www.nasaspaceflight.com (http://www.nasaspaceflight.com/content/?id=26):
Soviet scenario for NASA Shuttle salvage
4/18/2005 10:28:00 AM
By: Kathryn Hewitt
NASA engineers have been looking into the very real possibility of programming the Shuttles to return from orbit and land unmanned, independently from their crew. This would allow the astronauts to take refuge on the International Space Station in the event of problems, to avoid any future disasters upon the Orbiter's return to Earth.
This option is being researched since the loss of Columbia and her crew in 2003 and serves as another precautionary step towards ensuring a safer space flight.
In the past, one such unmanned return to Earth was successfully accomplished by a competitor Shuttle from the Soviet Union. The Russian Space Shuttle Buran made the unmanned flight in November 1988 and returned to a runway landing back in Russia. The Shuttle was controlled only by computers.
The NASA Shuttles already have a system that can automatically perform most landing functions. At present however, some key tasks - such as lowering the landing gear and deploying a pair of probes that collect airspeed, altitude and temperature data during the last moments of flight - require an astronaut at the controls.
"All of those things in a theoretical sense can be automated, but they are not currently connected to the computer system," said Wayne Hale, deputy director of the shuttle program on linking up elements such as deploying the landing gear.
Each Shuttle has automated systems, where computers debate and vote between themselves to decide the right course of action. However, this is mainly used on launches.
NASA's potential changes would allow the flight team on the ground to land an unmanned Orbiter by remote command.
Hale added "When we designed the Shuttle years ago, they [the elements] weren't [connected] for a variety of reasons." Hale then went on to state, "The modifications to allow that capability to be automated are going to take some time."
If that capability becomes a reality, it could give NASA an alternative to scuttling a damaged orbiter and allowing them to save themselves. Plans developed after the 2003 Columbia accident raise the possibility that future shuttle crews might seek safe haven at the space station if there is evidence their ship needs repairs, rather than risk the fiery plunge home through Earth's atmosphere.
02.02.2006
FYI the modification kit to allow the unmanned Shuttle Orbiter to be remotely undocked from the ISS and landed is now available and it will fly on STS-121.
It must have the crew install some cables and a switch box as well as set the Orbiter controls per a checklist before they close the hatch and retire to the ISS.. All normal functions can be commanded from the ground except for nose wheel steering and braking.
It is zero fault tolerant for loss of the vehicle. It is one fault tolerant and still have
the ability to be commanded to dive into the sea.
The landing site would be Edwards AFB.
Questo sta a significare che hanno pre-programmato un'intera sequenza di comandi (con le dovute correzioni/reazioni ai fattori ambientali) per far atterrare il Discovery alla base di Edwards e un'altra di emergenza per far ammarare l'orbiter (danneggiandolo pero' irreparabilmente).
Ho capito bene?
Bye
Questo sta a significare che hanno pre-programmato un'intera sequenza di comandi (con le dovute correzioni/reazioni ai fattori ambientali) per far atterrare il Discovery alla base di Edwards e un'altra di emergenza per far ammarare l'orbiter (danneggiandolo pero' irreparabilmente).
Ho capito bene?
Bye
Non si è trattato di una semplice riprogrammazione del software utilizzato dai 4 computer di bordo, ma anche dell'aggiunta di una serie di collegamenti e di una centralina di interfacciamento per l'avionica che permettesse di comandare gli attuatori dei carrelli e delle altre parti elettro-idraliche non ancora in grado di essere comandate indipendentemente dal computer.
Da Spaceflightnow.com:
NASA budget supports up to 17 space shuttle flights
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: February 6, 2006
By sharply reducing the growth of space science and other NASA programs over the next five years, NASA managers hope to erase a projected multi-billion dollar shortfall in the shuttle budget, permitting up to 17 missions between now and the program's retirement in 2010, including a possible flight to service the Hubble Space Telescope. Only two flights are expected this year, one in May and the other late this summer, as NASA struggles to complete its recovery from the Columbia disaster and finish a major overhaul of the shuttle Endeavour.
Unveiling NASA's fiscal 2007 budget, Administrator Mike Griffin said today the Bush administration is requesting $16.8 billion for the civilian space agency, a 3.2 percent increase over fiscal 2006.
The 2007 budget includes $5.3 billion for space science; $4 billion for development of a new manned spacecraft and other technologies for the president's moon-Mars exploration initiative; and $6.2 billion for the space shuttle and international space station projects.
To help make up a projected $3 billion to $5 billion shortfall in the shuttle budget between now and 2010, NASA plans to limit the growth of the space science budget to just 1.8 percent in 2007 and 1 percent per year thereafter. Doing so will defer the development of several major unmanned projects, including one to search for planets around other stars and another to detect Earth-like extra-solar worlds.
"Leadership means setting priorities," Griffin said today. "And leadership means making difficult decisions based on the best facts and analysis available. And one plain fact is NASA simply cannot afford to do everything that our many constituencies would like us to do. We must set priorities and we must adjust our spending to match those priorities."
To make up the projected shuttle shortfall, "we took a couple of billion out of science and a billion and a half out of the exploration line and made up what we needed to make up," Griffin said.
During a news conference last month, Griffin said NASA's space science budget would not be cut to fund the shuttle, the space station or the Bush administration's moon-Mars initiative. But growth would be reduced, he said.
"We are not whacking the space science program to pay for human exploration," he said in response to a question from CBS News. "This is not the 'Sopranos,' we don't whack people or programs here. We have, of course, in this nation, I do not need to be the one to tell you this, this is a difficult budgetary environment. NASA is not looking forward to any gifts of robust growth from either the administration or the Congress. We expect to keep approximately the funding we have, which will essentially be a very low growth funding profile and therefore, all of the components, each separate component of what NASA does can expect to have, at best, only modest growth.
"The difference between cuts and modest growth, I guess, needs to be explained to people. I think we're doing well and within NASA, the space science program is doing well and will continue to do well."
Today, a reporter asked the administrator, "last September you said that not one thin dime would be taken away from the science programs for human spaceflight and exploration. Is what you just said, that that's exactly what has been done, not just one thin dime but two billion dollars taken away from space science to complete the ISS?"
"Yep, that's right," Griffin said with his usual candor. "I wish we hadn't had to do it, I didn't want to, but that's what we needed to do."
The Planetary Society, an international space interest group, said today the president's 2007 budget request for NASA "shortchanges space science in order to fund 17 projected space shuttle flights."
"Despite recent spectacular results from NASA's science programs, this budget puts the brakes on their growth within the agency," the society said in a statement. "It seriously damages the hugely productive and successful robotic exploration of our solar system and beyond."
Society president Wesley Huntress, a former associate administrator for space science at NASA headquarters, said the agency is "essentially transferring funds from a popular and highly productive program into one scheduled for termination."
In January 2004, President Bush announced a new direction for NASA, telling the agency to complete the international space station and retire the shuttle by 2010; to develop a new crew exploration vehicle to replace the shuttle; and to use that spacecraft and other technologies to return astronauts to the moon by the end of the next decade. Returning to the moon is seen as a first step toward eventually launching humans to Mars.
NASA has been struggling to complete post-Columbia safety upgrades, which have cost far more than initially envisioned, and to come up with a space station assembly sequence that can meet long-standing international commitments and research objectives by the 2010 deadline. Twenty eight flights were required to meet the program's original objectives, but that number was whittled down to 18 last year and now, to 16, assuming two resupply flights are ultimately cancelled and replaced by commercial missions. NASA's 2007 budget includes money, however, to continue preparations for an additional flight to service the Hubble Space Telescope.
In the near term, NASA still hopes to launch the shuttle Discovery on the second post-Columbia mission, STS-121, during a window that opens May 3 and closes May 22. Because of hardware processing issues, NASA insiders say mid to late May is the current best guess as to an eventual launch date.
NASA's launch windows are limited because of a post-Columbia directive to launch the first few shuttle flights in daylight and to make sure external fuel tank separation occurs in daylight half a world away. NASA engineers want to make sure the tank's foam insulation doesn't break away during launch and good lighting is required for detailed ground- and space-based photo documentation.
Those requirements, along with the nature of the international space station's orbit, limit NASA to relatively infrequent windows. The next three are as follows:
I. May 3-22
II. July 1-19
III. Aug. 28 to Sept. 14
During the first post-Columbia mission last July, a large chunk of foam insulation broke away from a so-called protuberance air load - PAL - ramp on the side of Discovery's external fuel tank. The ramp, made of hand-applied foam insulation, was in place to smooth the flow of turbulent air over two external pressurization lines and a critical cable tray.
Late last year, NASA managers decided to simply eliminate the ramp after detailed computer analysis indicated the pressurization lines and cable tray are tough enough to withstand the expected buffeting as the shuttle breaks through the region of maximum aerodynamic pressure shortly after launch.
On the assumption upcoming wind tunnel tests in March will verify the earlier analyses, external tank No. 119, sans PAL ramp, will be shipped to the Kennedy Space Center from Lockheed Martin's Michoud (La.) Assembly Facility around March 3.
External tank No. 118, slated for use by the shuttle Atlantis for the third post-Columbia mission, STS-115, is not scheduled to arrive in Florida until late May. Atlantis and ET-118 will be on call for rescue duty in the event of a major problem during Discovery's upcoming flight that might force the crew to seek "safe haven" aboard the international space station.
Given ET-118's late arrival in Florida, a stranded crew would have a fairly long wait for a ride home. Assuming a mid-May launch for Discovery on mission STS-121, Atlantis would not be ready for rescue duty until around Aug. 4.
But space station managers say the orbital lab complex will have enough oxygen and other supplies on board by the time of Discovery's launch to support a combined crew for almost six months.
If Discovery does, in fact, get off in May and no major problems develop, NASA will process Atlantis for a launching in late August on mission STS-115.
At that point, if all goes well, NASA almost certainly will relax the daylight launch requirement. Even so, agency officials say, a third flight appears extremely unlikely this year because the shuttle Endeavour, currently undergoing a major overhaul, is not expected to be ready to fly mission STS-116 until early 2007.
Non si è trattato di una semplice riprogrammazione del software utilizzato dai 4 computer di bordo, ma anche dell'aggiunta di una serie di collegamenti e di una centralina di interfacciamento per l'avionica che permettesse di comandare gli attuatori dei carrelli e delle altre parti elettro-idraliche non ancora in grado di essere comandate indipendentemente dal computer.
Certo, avevo letto :D
Anche se per come la vedo, predisporre i collegamenti temporanei, agli apparati che attualmente non sono comandati dai computers, e' un lavoro piu' semplice che istruire (passami il termine) i computers stessi a controllare le loro nuove "periferiche" ed utilizzarle opportunamente.
Piu' di tutto, comunque, mi stupisce sempre la precisione con la quale pianificano ogni azione comprendendo per ciascuna almeno un piano di emergenza.
NASA studies shuttle engine seals, contamination issues
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: February 17, 2006
NASA now plans to ship the next external fuel tank to the Kennedy Space Center ahead of schedule and the shuttle Discovery's commander said today the astronauts remain optimistic about launching in May on the second post-Columbia mission. But a variety of technical issues remain on the table, including wind tunnel tests to show fuel tank changes will work as expected, an ice and debris analysis and, most recently, main engine seal leaks and metallic contamination in the main propulsion system.
The latter issue appears to be a generic problem in that metallic debris, estimated to weigh just 0.08 milligrams, has been found in the liquid oxygen prevalve filter screen used by Discovery's main engine No. 1 and also in an oxygen prevalve screen in the shuttle Endeavour. In the latter case, the debris is estimated to weigh 1.1 milligrams. The concern is that such debris, depending on its composition, could trigger a catastrophic fire during engine operation.
It is not yet known whether the shavings detected by boroscope inspections represent a real ignition threat, whether the shuttle can safely fly as is or whether time-consuming work to disassemble the system and remove the debris will be necessary. If so, NASA could be hard-pressed to launch Discovery before the next launch window closes May 22.
In a separate issue, Discovery's main propulsion system failed a helium leak test after engine installation and then failed it again after engineers detached the engines, installed different seals (two per engine) and reattached the powerplants. Engineers now plan to install the best seals in the shuttle inventory and carry out a third helium signature test to verify the integrity of the system.
If the system passes, NASA will press ahead with Discovery's processing for a launch as early as May 10. But the issue will remain open until engineers figure out what caused the original sealing problem or, if the problem involves hardware that does not meet specifications, whether the shuttle can fly safely with any such out-of-spec components.
At Lockheed Martin's Michoud Assembly Facility near New Orleans, meanwhile, engineers are readying external tank No. 119 for shipment to the Kennedy Space Center as early as next Friday, Feb. 24, a week ahead of schedule.
During Discovery's launch last July on the first post-Columbia mission, a large piece of foam insulation broke away from the liquid hydrogen section of the external tank's protuberance air-load - PAL - ramp. In the wake of that incident, NASA managers decided to remove the PAL ramps on all subsequent tanks, starting with ET-119.
The PAL ramps were added to the external tanks before the first shuttle mission to act as aerodynamic dams, shielding two external pressurization lines and a critical cable tray from buffeting as the shuttle goes supersonic in the dense lower atmosphere. Computer modeling now indicates the ramps aren't needed and that the pressurization lines and cable try are tough enough to endure whatever buffeting they might experience.
But wind tunnel tests are needed to confirm the computer results and that work will not be finished until next month.
"We resisted taking the PAL ramps off," shuttle program manager Wayne Hale told Kennedy Space Center workers today during an "all hands" briefing. "We were looking at taking the PAL ramps off eventually and we had this nice program, we were going to do a lot of wind tunnel tests, do all this analysis, instrument a couple of tanks and fly a couple of tanks and get the data that would prove without a shadow of a doubt we didn't need these PAL ramps. ... Clearly, supersonic aerodynamics, the forces that are imposed on the pressurization lines and the cable tray that run up the side of the tank on the outside, you don't want to fool around with that because you can't stand for those things to come loose. So we've got to do it right. That was in the plan."
But in the wake of Discovery's launch last July and inspections of a tank originally scheduled for the next mission, "we knew the PAL ramp had to go," Hale said. "So the big discussion was how can we prove this is safe to do?"
"We've done some very conservative kinds of analyses ... and that indicates we are probably OK to take it off," Hale said. "But it also has big uncertainty factors. And if you put the big uncertainty factors on it, it's not what you'd like. So we've got an expedited set of wind tunnel tests that we're running, first at the Glenn Research Center coming up in March and secondly, at the Arnold Engineering Development Center in Tullahoma, Tenn., in June. You might detect that June is kind of after when we'd like to fly."
But Hale said by around April 1, engineers should have "some numbers that we can at least hang our hat on and if we pass go at that point, which is to say the structure will hold together as we go supersonic on the tank, then life is good. We're not really sure that's going to happen, that's why we've got the Glenn Research Center wind tunnel tests, which has a full-scale part of the tank with these lines and cable trays. Putting that model together and getting it into a wind tunnel is not something they do overnight."
Wind tunnel testing will run through March. Data will be compared to the engineering analysis and "hopefully say, you know, we were too conservative and the loads are actually less than this conservative analysis, we can reduce the uncertainty."
But if the March testing generates less definitive results, additional higher-fidelity tests will be conducted at Arnold in June and Discovery's flight will slip into the July launch window and possibly even later.
"This is a success-oriented schedule," Hale said. "We are betting, as we do frequently, that we will be smart enough to say we're good to go. But if the answer comes out bad, we'll put the red flag out and we'll say we've got to wait until the July launch window to get the AEDC wind tunnel test results back.
"We're all assuming the analysis will show the structure as it stands is good to fly, that it's got the strength necessary to withstand the aerodynamic loads. But I won't kid you, if the answer comes back and says, you know, the cable tray will come off, that's not something we're going to fly with. And then we'll have to sit down and scratch our heads.
"So here's the story," Hale concluded. "We are working towards, as we always seem to in this business, an optimistic (schedule for a May launch). The data has got to prove it is safe to go fly. If the data doesn't come in in time, or the data says it's not safe to fly, then we'll stop what we're doing and go to plan B. I have a great deal of confidence the data will show we are safe to go fly, but it's going to be what it's going to be. ... Welcome to our world."
Other long poles in the processing tent include completion of a detailed ice and debris threat analysis; possible work to replace additional "gap fillers" between heat shield tiles on the orbiter's belly; and work to confirm a long boom that will be used to carry out post-launch heat shield inspections in orbit can withstand launch forces.
Discovery commander Steven Lindsey and five of his six crewmates - pilot Mark Kelly, Michael Fossum, Lisa Nowak, Stephanie Wilson and Piers Sellers - spoke with reporters today at the Kennedy Space Center and expressed confidence about getting off in May.
"The foam problem, obviously we're working on it," Lindsey said. "Everybody knows what happened on 114 (Discovery's last flight). The PAL ramp foam problem, I think we have solved since we've taken the PAL ramp foam off the tank and it won't be there. The data that I've seen ... I'm pretty confident that's the right decision and we're going to be OK on that."
Lindsey said "the program has never advertised that we will never lose any foam. And we'll lose foam on this flight."
"The key is, to make sure the foam we do lose is small enough that it can't hurt us if it hits the vehicle," he said. "And that's what we're working towards. So I feel pretty confident that the decisions we're making based on the information we have and the engineering analysis and wind tunnel testing, we're going in the right direction."
Even so, he cautioned, "this is a test flight and part of the purpose of this test flight is to test the changes we've made to the tank. And so obviously, we won't know for sure until we fly it."
During Discovery's flight last summer, spacewalker Stephen Robinson, riding on the end of the space station's robot arm, ventured under the nose of the shuttle to remove two protruding gap fillers that had shaken loose during launch. The gap fillers provide a sort of protective cushion between tiles during launch and re-entry. Gap fillers that protrude into the airstream during re-entry can cause excessive localized heating.
In the wake of Discovery's last flight, engineers have replaced gap fillers in critical areas.
"The gap fillers, we're in the process of replacing a bunch of them and making sure they're secure," Lindsey said. "As everyone knows, we had one come loose and had to pull it out on the last flight. We've got the primary zones done on the gap fillers, there are some more zones that we just signed up to do that still supports May. There is still some debate going on over another section and whether we need to pull those.
"As far as I know, I don't think that in particular is threatening the May launch date. There is a lot of work going on to get the tank ready, to get the tank shipped on time, to do a good tank flow here to get us all ready to go. There are a whole bunch of things out there. Right now, we're still holding to May, we're training to May and the program is marching toward May. We'll see.
"The only kind of risk we want to take here is a schedule risk, not a technical risk. Nothing technically is being eliminated for the May launch date. We're doing everything technically that we would normally. If we get to a point where, from a schedule standpoint it doesn't make May, then we're going to slip. But we're not going to skip any technical steps."
Spaceflightnow.com
NASA plans to park space shuttle Atlantis in 2008
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: February 17, 2006
With just 17 or so flights left on the shuttle manifest before the program is terminated in 2010, NASA's three remaining orbiters can only expect to fly about five missions each. As it turns out, NASA now plans to retire Atlantis in 2008, after five flights, rather than put it through a required overhaul and to "fly out" the remaining half-dozen missions on the manifest with Discovery and Endeavour.
But shuttle program manager Wayne Hale told Kennedy Space Center employees today that Atlantis will not be given to a museum, at least not right away. Instead, the space shuttle will be used for spare parts to help keep Discovery and Endeavour healthy through the end of the program.
"Atlantis will be coming due for an OMDP (orbiter maintenance down period) in the '08 time frame," Hale said. "And we looked the manifest and laid it out and we believe we can fly the '08, '09 and '10 time frame with Discovery and Endeavour.
"Discovery just came out of OMDP and Endeavour is just about to come out of OMDP. So it looks like the right thing to do is not to put Atlantis through another OMDP, which would get it ready to go fly maybe just at the very end, in 2010, but rather use it was a parts donor, if that's the word, for the other vehicles.
"So we're going to try to keep it in as near flight ready condition as we can without putting it through an OMDP so we can use those parts," Hale said. "Quite frankly, people are already calling us and asking us can they display one of our orbiters in their museum after we're done with it. I'm not giving anybody anything until we're all agreed the station is complete and the shuttle's job is done. In the sense that we're talking about mothballing, I'm not sure that's the term I'd use."
All shuttles are required to undergo periodic inspections and modifications to maintain their overall health. Such OMDP overhauls can take a year or more to complete.
L'ET-119 lascia la Michoud Assembly Facility per il KSC:
NASA Press Release
The tank that will help launch Space Shuttle Discovery on its next mission is heading to NASA’s Kennedy Space Center in Florida this weekend.
The huge orange tank, designated ET-119, will be loaded on a covered barge today at the Michoud Assembly Facility near New Orleans for the five to six days to travel to Florida's Banana River.
At Kennedy, the tank will be delivered to the Vehicle Assembly Building for final checkout and eventually attached to the twin solid rocket boosters and Discovery for its mission (STS-121) to the International Space Station. NASA managers are targeting a launch window for Discovery in May.
Meanwhile, Six of the seven crew members of the next return-to-flight mission, STS-121, converged at NASA's Kennedy Space Center in Florida on Feb. 17 and 18 to take part in the Crew Equipment Interface Test.
The astronauts typically gather before flight to inspect the orbiter, and this mission is no exception. The crew will fly on Discovery to the International Space Station to deliver more supplies and cargo for future station expansion.
http://www.nasa.gov/images/content/143661main_ET-119_2.jpg
Da Space Flight Now
Shuttle fuel tank en route; Schedule options debated
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: February 27, 2006
The shuttle Discovery's modified external tank may arrive at the Kennedy Space Center Wednesday, a day early, to kick off the final push toward launch of the second post-Columbia shuttle mission. But agency officials say unfinished foam work, testing and resolution of other on-going issues will make it extremely difficult for NASA to meet its May target launch date.
Even so, shuttle program manager Wayne Hale, chairing an external tank shipment review last week at the Marshall Space Flight Center in Huntsville, Ala., opted to stick with a May 10 target date pending additional discussions at this Thursday's program requirements control board - PRCB - meeting in Houston.
Hale will participate in a shuttle program update news conference Tuesday at the Kennedy Space Center.
External Tank 119 departed Lockheed Martin's Michoud Assembly Facility by barge on Saturday, nearly a week ahead of schedule. But engineers face up to 10 days of additional foam closeout work in Florida as the space agency gears up for normal launch processing.
NASA planners have been baselining an accelerated 62-day processing flow that typically includes five days of contingency time to handle unexpected problems. Depending on how much post-shipment foam work is actually required for ET-119, that contingency time could shrink to zero or even go negative, i.e., push the launch to later in May. As it now stands, a full 10 days of post-shipment work would drive the launch date to around May 12 with no contingency time. A meeting to discuss tank processing issues is planned for Tuesday.
Other "long poles" in the launch processing schedule include positive results from upcoming wind tunnel tests to verify recent tank modifications will work as advertised; a launch ice/debris analysis; and final design reviews associated with the tank work.
Engineers are also working two issues with the shuttle's main propulsion system that must be resolved before flight.
After two helium leak test failures, replacement seals were installed between two of the ship's three main engines and propellant feed lines. The propulsion system is now leak free. But three of the four seals in question do not quite meet printed specifications and engineers are conducting an analysis to show the seals will work as required. NASA also is working with the vendor to ensure compliance with specifications in the future.
Another open issue involves small metal fragments trapped on a filter screen above a liquid oxygen main engine inlet. Similar debris was seen in a filter screen in the main propulsion system aboard the shuttle Endeavour and engineers are trying to figure out whether the material represents an ignition threat. If the debris must be removed before flight, Discovery would not be able to meet the May launch window, officials said. See the Feb. 17 story for additional details.
That said, here is the latest near-term launch schedule. Readers are advised that recent discussions of long-term manifest options on this page and other sites have been superceded by a new space station assembly sequence (see below); the following target dates are topics on the agenda at Thursday's PRCB meeting and thus subject to change:
STS-121/ET-119 (Discovery/ISS-ULF 1.1): 05/10/06
STS-300/ET-118 (Atlantis/emergency rescue mission): 08/04/06 (if needed)
STS-115/ET-118 (Atlantis/ISS-12A): 08/28/06
STS-301/ET-123 (Discovery/emergency rescue mission): 10/28/06 (if needed)
STS-116/ET-123 (Discovery/ISS-12A.1): 11/16/06
STS-116 is officially slated for the shuttle Endeavour. But Endeavour, currently undergoing a major inspection and overhaul, will not be ready to fly before February and NASA almost certainly will switch that flight to Discovery. And that, in turn, would delay implementation of a major modification planned for Discovery that will permit it to use space station electrical power when docked to the orbital outpost.
As it now stands, the shuttle can transfer its own 28-volt power into the station's 120-volt system, but it doesn't work the other way around. Using a new Boeing-supplied Power Converter Unit, the shuttle will be able to augment its own fuel cell-generated power with station electricity, allowing future crews to remain docked for nine to 12 days. That's a high-priority upgrade to maximize the time available for assembly work, but modifications to Discovery will be deferred one flight if Discovery does, in fact, stand in for Endeavour.
The space station, of course, is the major manifest driver. All but one of the 17 flights remaining between now and the end of the shuttle program in 2010 are devoted to space station assembly, resupply and maintenance. The lone exception is a possible flight to service and upgrade the Hubble Space Telescope.
While that mission carries a high scientific priority, it is not yet clear how NASA will conduct a flight that cannot take advantage of the international space station if the orbiter suffers any significant damage during launch or in orbit.
Space station-bound shuttle crews can use the lab complex as a "safe haven" in the event of major problems, but that option isn't available to a Hubble crew because the shuttle does not have the ability to move from one craft's orbit to the other. A decision on how to proceed ultimately could play a role in when NASA turns over one of its two shuttle launch pads for modifications to support the new Crew Exploration Vehicle.
Shuttle managers would like to keep pad 39B available in case the agency ultimately decides a second shuttle must be prepared for a quick-launch emergency mission to protect the Hubble crew. All of that remains up in the air as of this writing, but it is a factor in manifest planning and CEV test flight scenarios.
NASA had been hoping to launch a Hubble servicing mission eight or nine flights into the new sequence. But the agency is expected to move up launch of two key European and Japanese space station modules, at the request of the international partners, pushing a Hubble flight to early 2008 on the 11th mission in the latest proposed manifest.
NASA Administrator Mike Griffin and his international counterparts plan to discuss the station assembly sequence at a "heads of agencies" meeting Thursday at the Kennedy Space Center. A news conference is planned Thursday afternoon.
The European and Japanese space agencies, sources say, have been adamant about moving up the launch of ESA's Columbus research module and the Japanese Kibo module. NASA planners initially resisted the idea because it complicated logistics and sequential assembly work.
Ma alla fine, l'ET 119 e' "nato" senza PAL ramp mentre all'ET 118 viene/verra' rimossa?
AlexGatti
01-03-2006, 10:11
faccio una domanda stupida, ma è per capire come funziona la cosa, ditemi dove sbaglio:
La sequenza di lancio prevede che in una prima fase siano accesi i due booster e il motore principale. Questa fase non ha (quasi) mai dato problemi, o comunque sono stati risolti
In una seconda fase i due booster laterali si staccano dal serbatoio e ricadono nell'oceano mentre lo shuttle continua con i motori principali alimentati dal serbatoio. Neanche questa fase ha mai dato problemi grossi
Terza fase: Infine si stacca il serbatoio principale che si disintegrerà nell'atmosfera, mentre lo Shuttle continua ancora un po'con i motori principali alimentati da un (piccolo immagino) serbatoio interno. In questa fase ci sono i problemi di schiuma che si stacca, specie durante il distacco del serbatoio, e colpisce lo scudo termico.
Bene, la domanda è questa: Perchè non è fattibile mandare in orbita lo Shuttle evitando il distacco del serbatoio principale?
Ovvero facendo una cosa di questo genere:
La terza fase viene saltata, lo shuttle arriva in orbita con il serbatoio principale attaccato (dovrà caricare un po' più di carburante).
A questo punto il serbatoio viene staccato meccanicamente (non tramite cariche esplosive) o addirittura a mano (Tramite EVA di due astronauti).
Infine un piccolissimo booster provvede a dare la spintarella al serbatoio in modo da farlo disintegrare nell'atmosfera nel giro di qualche giorno.
In questo modo verrebbe evitato il momento di maggior rischio. Probabilmente si dovrebbe caricare un po' più di carburante (quanto?) limitando il carico utile dello shuttle o ingrandendo il serbatoio principale.
Probabilmente un po' di peso si potrebbe risparmiare sulle strutture di attacco sia sullo Shuttle sia sul serbatoio perchè non devono più resistere allo shock del distacco. Inoltre niente più cariche esplosive.
Penso che se questo non è stato fatto ci sarà un motivo. Qual è?
faccio una domanda stupida, ma è per capire come funziona la cosa, ditemi dove sbaglio:
La sequenza di lancio prevede che in una prima fase siano accesi i due booster e il motore principale. Questa fase non ha (quasi) mai dato problemi, o comunque sono stati risolti
In una seconda fase i due booster laterali si staccano dal serbatoio e ricadono nell'oceano mentre lo shuttle continua con i motori principali alimentati dal serbatoio. Neanche questa fase ha mai dato problemi grossi
Terza fase: Infine si stacca il serbatoio principale che si disintegrerà nell'atmosfera, mentre lo Shuttle continua ancora un po'con i motori principali alimentati da un (piccolo immagino) serbatoio interno. In questa fase ci sono i problemi di schiuma che si stacca, specie durante il distacco del serbatoio, e colpisce lo scudo termico.
Bene, la domanda è questa: Perchè non è fattibile mandare in orbita lo Shuttle evitando il distacco del serbatoio principale?
Ovvero facendo una cosa di questo genere:
La terza fase viene saltata, lo shuttle arriva in orbita con il serbatoio principale attaccato (dovrà caricare un po' più di carburante).
A questo punto il serbatoio viene staccato meccanicamente (non tramite cariche esplosive) o addirittura a mano (Tramite EVA di due astronauti).
Infine un piccolissimo booster provvede a dare la spintarella al serbatoio in modo da farlo disintegrare nell'atmosfera nel giro di qualche giorno.
In questo modo verrebbe evitato il momento di maggior rischio. Probabilmente si dovrebbe caricare un po' più di carburante (quanto?) limitando il carico utile dello shuttle o ingrandendo il serbatoio principale.
Probabilmente un po' di peso si potrebbe risparmiare sulle strutture di attacco sia sullo Shuttle sia sul serbatoio perchè non devono più resistere allo shock del distacco. Inoltre niente più cariche esplosive.
Penso che se questo non è stato fatto ci sarà un motivo. Qual è?
Potrei ipotizzare che il distacco dell'isolante dall'External Tank, anche se in piccoli frammenti avvenga durante tutta la fase di ascesa (meno nella fase iniziale quando la velocita' non e' elevatissima e l'attrito aerodinamico e' minore)
Se cosi' fosse, non avrebbe senso portarsi dietro tutto quel peso; anzi, meno tempo l'orbiter passa attaccato all'ET meno rischio c'e' di essere colpito da frammenti di qualsiasi tipo.
Ripeto, questo discorso ha senso solo se la mia affermazione iniziale risulta corretta..
Attendiamo risposta da GioFX.. ;)
Piccolo Lord
01-03-2006, 16:03
Come titolo di questo thread metterei
"NASA - Giofx's copy&paste skills"
:fagiano:
Ma alla fine, l'ET 119 e' "nato" senza PAL ramp mentre all'ET 118 viene/verra' rimossa?
No, entrambe erano già state costruite con la rampa, l'ET-119 doveva volare con l'Atlantis, ma è stata riconvertita per il Discovery dopo l'STS-114.
La sequenza di lancio prevede che in una prima fase siano accesi i due booster e il motore principale. Questa fase non ha (quasi) mai dato problemi, o comunque sono stati risolti
Si, cmq in realtà la sequenza automatica di lancio più nel dettaglio si svolge così:
A T-6 secondi vengono accesi i SSME (Space Shuttle Main Engines).
Durante i 6 secondi che separano questo evento dall'accensione a T-0 dei due SRB i computer di bordo dell'orbiter controllano costantemente lo stato dei motori, delle tubopompe, del flusso del propellente, della temperatura, ecc.
A T-0 i due booster vengono accesi allo stesso istante (le tolleranze sono di pochi millisecondi) e SOLO quando l'orbiter è in assoluta posizione verticale (perchè l'ortbiter è in oscillazione a seguito dell'accensione dei motori principali)
Nel momento in cui lo shuttle lascia la torre di lancio (circa 7 secondi dopo l'accensione) il comando della missione passa al controllo missione di Houston.
In una seconda fase i due booster laterali si staccano dal serbatoio e ricadono nell'oceano mentre lo shuttle continua con i motori principali alimentati dal serbatoio. Neanche questa fase ha mai dato problemi grossi
Esatto.
Terza fase: Infine si stacca il serbatoio principale che si disintegrerà nell'atmosfera, mentre lo Shuttle continua ancora un po'con i motori principali alimentati da un (piccolo immagino) serbatoio interno. In questa fase ci sono i problemi di schiuma che si stacca, specie durante il distacco del serbatoio, e colpisce lo scudo termico.
No... i motori sono alimentati esclusivamente dall'external tank, circa 10 minuti dopo la partenza i motori vengono spenti PRIMA che il propellente finisca. Ci sono due circuiti indipendenti di quattro sensori che verificano, 2 nel serbatoio dell'ossigeno ed altrettanti in quello di idrogeno, costantemente il livello del propellente e, in caso scienda oltre una certa soglia, spengono i motori. Per ovvi motivi questo sistema viene attivato solo dopo qualche secondo dalla partenza, per evitare che vengano spenti i motori subito dopo la partenza, anche perchè si presume che il serbatoio sia pieno.
Il problema maggiore che ha causato il ritardo nel lancio dell'ultima missione STS-114 l'anno scorso fu dovuta ad uno di questi sensori, o meglio alla sua installazione.
Cmq il momento più pericoloso durante la fase di lancio è quando vi è il distacco dei booster, perchè più facilmente si possono staccare pezzi di schiuma isolante dall'ET.
In ogni caso l'incidente al Columbia è occorso prima della separazione, circa 73 secondi dopo il decollo.
Bene, la domanda è questa: Perchè non è fattibile mandare in orbita lo Shuttle evitando il distacco del serbatoio principale?
Ovvero facendo una cosa di questo genere:
La terza fase viene saltata, lo shuttle arriva in orbita con il serbatoio principale attaccato (dovrà caricare un po' più di carburante).
A questo punto il serbatoio viene staccato meccanicamente (non tramite cariche esplosive) o addirittura a mano (Tramite EVA di due astronauti).
Infine un piccolissimo booster provvede a dare la spintarella al serbatoio in modo da farlo disintegrare nell'atmosfera nel giro di qualche giorno.
In questo modo verrebbe evitato il momento di maggior rischio. Probabilmente si dovrebbe caricare un po' più di carburante (quanto?) limitando il carico utile dello shuttle o ingrandendo il serbatoio principale.
Probabilmente un po' di peso si potrebbe risparmiare sulle strutture di attacco sia sullo Shuttle sia sul serbatoio perchè non devono più resistere allo shock del distacco. Inoltre niente più cariche esplosive.
Penso che se questo non è stato fatto ci sarà un motivo. Qual è?
Il motivo è presto detto... primo come ho già sottolineato la fase di distacco dell'ET non è affatto la fase più pericolosa, la quale per la precisione avviene in orbita, quindi fuori dall'atmosfera. Inoltre la separazione è totalmente meccanica, non vi sono cariche come nel caso dei booster.
Questo basta, secondo me, a far capire il perchè non vi sia proprio il senso di una soluzione alternativa per questa particolare sequenza.
Detto questo, il distaccho di schiuma isolante dal serbatoio esterno (che ovviamente si sono sempre verificati nella storia del programma STS e solo in un caso hanno avuto come si sa hanno causato un problema tragico), diventa un problema potenzialmente fatale in particolari momenti e circostanze: fase del volo (quindi velocità dello shuttle e condizioni termiche) e dimensione.
Il pezzo staccatosi dal Columbia causò un danno fatale all'orbiter perchè il tutto avenne nella fase di maggior accelerazione dello shuttle (anche se non alla velocità più elevata in assoluto), e relativamente presto nel volo, quindi ancora nella parte più densa dell'atmosfera. Anche la sua dimensione ha giocato un ruolo importante.
Il pezzo infatti è stato decelerato di parecchio subito dopo il distacco, dato il suo bassissimo peso specifico e la sua discreta dimensione. In questo modo si è trasformato in un proiettile che ha bucato la copertura RCC (Reinforced Carobon-Carbon) del profilo alare (leading edge).
La caduta del pezzo dalla PAL ramp durante la missione 114 del Discoveri lo scorso luglio, la prima del RTF - ritorno al volo, è avvenuta invece ben più tardi durante il volo e, oltre a non colpire l'orbiter, non avrebbe comunque potuto causare gli stessi danni in quanto la sua velocità relativa rispetto allo shuttle era di molto inferiore, perchè nella mesosfera l'aria è molto più rarefatta. Se si guardano i due video, quello del lancio del STS-107 e quello del STS-114 nei punti incriminati, si nota molto chiaramente.
Nel primo caso non si nota se non al rallentatore, nell'altro e ben visibile a velocità normale.
STS-107:
http://spaceflightnow.com/shuttle/sts107/030201columbia/launchdebris.gif
STS-114:
http://www.spaceflightnow.com/shuttle/sts114/050726images/debris.jpg
Per i video:
http://24.73.239.154:8081/wwwroot_45/DIVX/space_shuttle_divx_video.htm
:)
Spero di essere stato abbastanza chiaro... :)
AlexGatti
01-03-2006, 23:58
Spero di essere stato abbastanza chiaro... :)
Chiarissimo, grazie.
Vedi, tante cose che non sapevo o che immaginavo diverse :D :fagiano:
[...]
Nel primo caso non si nota se non al rallentatore, nell'altro e ben visibile a velocità normale.[...]
Se non sbaglio per la missione STS-114 avevano installato molte piu' telecamere appunto per poter monitorare eventuali distacchi di frammenti di isolante..
AlexGatti
02-03-2006, 09:40
Visto che prima avevo cannato faccio un'altra domanda stupida:
Visto che il distacco dei boosters è l'evento più traumatico, perchè non attaccare i due boosters dalla parte opposta del serbatoio rispetto allo shuttle.
Ovvero: se ora lo shuttle è attaccato "davanti" al serbatoio e i boosters "ai lati" del serbatoio, non si potrebbe attaccare invece i boosters "dietro" al serbatoio? in modo che ogni pezzo di schiuma perso a causa del distacco dei boosters si trovi probabilmente già lontano dallo shuttle.
Però non ho idea della differenza di stress meccanici sul serbatoio che potrebbe esserci.
Visto che prima avevo cannato faccio un'altra domanda stupida:
Visto che il distacco dei boosters è l'evento più traumatico, perchè non attaccare i due boosters dalla parte opposta del serbatoio rispetto allo shuttle.
Ovvero: se ora lo shuttle è attaccato "davanti" al serbatoio e i boosters "ai lati" del serbatoio, non si potrebbe attaccare invece i boosters "dietro" al serbatoio? in modo che ogni pezzo di schiuma perso a causa del distacco dei boosters si trovi probabilmente già lontano dallo shuttle.
Però non ho idea della differenza di stress meccanici sul serbatoio che potrebbe esserci.
Ammazza.. temo sia una soluzione un po' poco praticabile... Penso richiederebbe un ri-calcolo dei baricentri, delle spinte, e, non ultimo l'adattamento dei pad 39 A e B.
:rolleyes:
Bye :)
Se non sbaglio per la missione STS-114 avevano installato molte piu' telecamere appunto per poter monitorare eventuali distacchi di frammenti di isolante..
Esatto. Era una delle procedure da adottare come richiesto dal rapporto finale del CAIB (Columbia Accident Investigation Board).
Visto che prima avevo cannato faccio un'altra domanda stupida:
Visto che il distacco dei boosters è l'evento più traumatico, perchè non attaccare i due boosters dalla parte opposta del serbatoio rispetto allo shuttle.
Ovvero: se ora lo shuttle è attaccato "davanti" al serbatoio e i boosters "ai lati" del serbatoio, non si potrebbe attaccare invece i boosters "dietro" al serbatoio? in modo che ogni pezzo di schiuma perso a causa del distacco dei boosters si trovi probabilmente già lontano dallo shuttle.
Però non ho idea della differenza di stress meccanici sul serbatoio che potrebbe esserci.
Veramente è impossibile per questioni meramente meccaniche, un sistema del genere ruoterebbe su un asse trasversale trasformando lo shuttle in una trottola infernale... basti considerare la spinta fornita dai booster rispetto a quella generata dagli SSME. E questo senza considerare le forze coinvolte, la distribuzione dei pesi, ecc.
Da il STS Reference (http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/srb.html):
The two SRBs provide the main thrust to lift the space shuttle off the pad and up to an altitude of about 150,000 feet, or 24 nautical miles (28 statute miles). In addition, the two SRBs carry the entire weight of the external tank and orbiter and transmit the weight load through their structure to the mobile launcher platform. Each booster has a thrust (sea level) of approximately 3,300,000 pounds at launch. They are ignited after the three space shuttle main engines' thrust level is verified. The two SRBs provide 71.4 percent of the thrust at lift- off and during first-stage ascent. Seventy- five seconds after SRB separation, SRB apogee occurs at an altitude of approximately 220,000 feet, or 35 nautical miles (41 statute miles). SRB impact occurs in the ocean approximately 122 nautical miles (141 statute miles) downrange.
Da Spaceflightnow.com (http://spaceflightnow.com/shuttle/sts121/060301tankarrival):
Discovery's fuel tank arrives at Kennedy Space Center
Posted: March 1, 2006
http://spaceflightnow.com/shuttle/sts121/060301tankarrival/tankbarge.jpg
The Pegasus barge carrying Discovery's fuel tank approaches Port Canaveral today. Credit: NASA-KSC
The external fuel tank for the next space shuttle mission sailed into Kennedy Space Center today, capping a 900-mile trip inside a covered barge from the New Orleans manufacturing plant to the Florida launch site.
Pulled by the Freedom Star, one of NASA's solid rocket booster retrieval ships, the Pegasus tank barge reached Port Canaveral at lunchtime. Tugboats maneuvered the barge into the receiving dock shortly after 5 p.m.
The Lockheed Martin-made tank left the Michoud Assembly Facility in Louisiana on Saturday.
Crews plan to offload the tank this evening and tow it into the Vehicle Assembly Building for several weeks of post-arrival testing, final work on the foam insulation and preparations for mating with the solid rocket boosters.
The boosters have been stacked atop a mobile launch platform. After the tank is added to the stack, space shuttle Discovery will be brought over from its nearby hangar for attachment. Rollout to launch pad 39B will occur a few weeks before liftoff.
This tank, known as ET-119, has been modified since the STS-114 shuttle launch last July, including removal of two Protuberance Air Load (PAL) ramps. One was a 14-foot-long, 14-pound strip of foam at the top of the liquid oxygen portion of the tank; the other was 38 feet in length consisting of 21 pounds of foam on the liquid hydrogen tank.
The ramps were designed to protect a cable tray and pressurization lines running up the exterior of the tank from aerodynamic loads during launch. But after Discovery's mission last year in which a large chunk of the hydrogen PAL ramp broke free, NASA was eager to remove the strips from future tanks.
Analysis has shown that the ramps aren't necessary. However, wind tunnel tests to prove the tank structures will survive the forces of ascent without the PAL ramps do not begin until mid-March.
Da Spaceflightnow.com (http://www.spaceflightnow.com/shuttle/sts121/060306rmsbump):
Shuttle Discovery's robotic arm examined after 'bump'
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: March 6, 2006
Engineers are looking under the insulation on the shuttle Discovery's robot arm to make sure an inadvertent "bump" by a moving servicing bucket didn't cause any damage.
The incident began when a light in the shuttle's Orbiter Processing Facility hangar broke, raining a small amount of glass into Discovery's open cargo bay. During work over the weekend to vacuum up the fragments, the safety rail around the top of a telescoping bucket used to move workers from point to point in and around the shuttle's cargo bay bumped the 50-foot-long robot arm mounted along the left side of the bay.
Sources said it did not appear the incident caused any major damage, but the results of a detailed inspection are not yet known, according to a NASA spokeswoman.
During Discovery's upcoming mission, the shuttle arm will be used to pick up a long boom equipped with cameras and laser sensors to inspect the shuttle's heat-shield system after launch. In addition, two astronauts will ride about on the end of the boom during the first of three planned spacewalks as part of an engineering study to evaluate the extended arm-boom system's stability. The idea is to find out if the system could be used for heat-shield repair work if such work is ever needed.
To help evaluate the loads on the arm-boom system, Discovery's robot arm has been instrumented and engineers want to make sure the arm itself and the instrumentation were not damaged by the work bucket incident.
NASA assesses unexpected reading from fuel tank sensor
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: March 7, 2006
Shuttle engineers are studying what, if anything, to do about an unexpected reading from one of four liquid hydrogen main engine cutoff - ECO - sensors in Discovery's external fuel tank, officials said today. The sensors play a critical role during the climb to space by ensuring a shuttle's main engines shut down normally before draining the ship's external tank. A malfunction could trigger an early engine shutdown or let the powerplants run too long.
http://www.spaceflightnow.com/shuttle/sts121/060307ecosensor/externaltanket119.jpg
Discovery's external fuel tank is lifted to a checkout bay inside the Vehicle Assembly Building last week for pre-flight preparations.
Discovery's launch last year was delayed because of ECO sensor problems that cropped up during pre-flight fueling tests. While engineers were never able to conclusively resolve the issue, data showed the problem was not generic and NASA managers approved a rule change that would have permitted Discovery to fly with three of four operational ECO sensors if the same problem showed up again. As it turned out, the rule change was not needed. On launch day, the sensors behaved normally.
This time around, a possible problem was noticed before external tank No. 119 - the one Discovery will use on its next flight - was shipped to Florida from Lockheed Martin's Michoud Assembly Facility near New Orleans. The tank arrived at the Kennedy Space Center last week.
During an all-systems electrical check at Michoud, a NASA spokesman said, liquid hydrogen ECO sensor No. 3 showed a 2-ohm shift from what engineers expected. The test was carried out again and ECO-3 showed the same reading.
"They haven't done anything since," said a NASA spokesman at the Johnson Space Center in Houston. "They're down there (at the Kennedy Space Center) processing the tank (for launch) and they're still talking about it."
The unexpected reading is within or very close to design specifications and it's not yet clear if anything will need to be done. If the sensors have to be replaced, engineers will need between one and three weeks to get inside the tank and make the swap.
"But you don't know if you've corrected the problem because you don't know if it's in the sensors or the connector and wiring behind it," the NASA spokesman said.
In the meantime, engineers are reviewing possible flight rationale to fly with three of four sensors much like the agency was prepared to do with Discovery's last launch.
An independent web site that covers NASA operations reported today that launch would be delayed for an ECO sensor swap out. But no such decisions have been made, according to shuttle program manager Wayne Hale. The issue has not yet even been elevated to Hale's level and it is far from clear what, if any, impact it might have on plans to launch Discovery during a 12-day window starting May 10. The next window opens July 1.
But Discovery's processing schedule has no built-in contingency time, and an ECO sensor swap-out would clearly pose an additional threat to the May window.
Hale told the shuttle team Monday, sources said, that the May launch target is threatened on a variety of fronts and that figuring out whether it makes sense to reshape foam insulation making up so-called ice/frost ramps on the exterior of the tank remains a long pole in the tent (see earlier status reports for details). But Hale said he plans to stick with May 10 while engineers collect additional data.
A discussion on whether to modify the shape of the ice/frost ramps is planned for March 23.
NASA.gov:
NASA announces new window for next shuttle mission
NASA NEWS RELEASE
Posted: March 14, 2006
NASA announced today July 1 to 19, 2006, is the new launch planning window for Space Shuttle Discovery's mission (STS-121). The window gives the agency time to do additional engineering work and analysis to ensure a safe flight for Discovery and its crew.
Space Shuttle Program Manager Wayne Hale made the announcement during a news conference from NASA's Johnson Space Center in Houston. The decision to target July followed a two-day meeting on the external fuel tank's engine cutoff (ECO) sensors. The sensors indicate whether the tank still has fuel during liftoff. During testing, one of the four ECO sensors had a slightly different reading than is expected. Shuttle officials have decided they will remove and replace all four liquid hydrogen sensors.
"We've been saying for months that our engineering work would determine when we fly our next mission. Targeting July is the right choice in order to make smart decisions," said Bill Gerstenmaier, NASA associate administrator for Space Operations.
Other issues factored into the decision to adjust the STS-121 planning window:
- Testing and analysis are required on the shuttle's modified external tank. The testing will help verify the tank is safe to fly without the protuberance air load (PAL) foam ramp. The PAL ramp was removed after a large piece of foam fell from that area during Discovery's July 2005 launch. More analysis is needed to decide whether changes are needed on the tank's ice frost foam ramps.
- Repair work on the shuttle's robotic arm must be completed. Technicians on a work platform accidentally bumped the arm last week, causing a tiny crack. The arm will be removed for repair.
The STS-121 mission will take Shuttle Commander Steve Lindsey and six crew members to the International Space Station. This is the second mission in the Return to Flight sequence to evaluate new heat shield inspection and repair techniques and to deliver supplies and equipment to the station.
Alla fine hanno deciso per scalare a Luglio..
Ma ricordo male io o inizialmente bastavano 3 sensori ECO su 4 funzionanti per poter procedere al lancio?
Allora, quella dei 3 ECO su 4 è una possibile deroga al LCC (Launch Commit Criteria) che consentirebbe in teoria di lanciare con 3 dei 4 sensori funzionati.
Era una possibilità durante il lancio dell'ultima missione STS-114 ma non è mai stata adottata. Anche se un fallimento di un ECO è altamente improbabile si è preferito, in presenza di una tolleranza troppo variabile anche se assolutamente dentro i limiti, di andare per la via più sicura che è quella di sostituire tutti e quattro i sensori con dei nuovi e più recenti che dovrebbero essere esenti da questa sensibilità marcata verso le sollecitazioni meccaniche e termiche.
Si è visto infatti che i wet-failures, funzionamenti errati con lettura di stato "bagnato", cioè essenzialmente serbatoio carico quando invece è vuoto (ho spiegato già come funziona il tutto in un post passato) si sono verificati soprattutto dopo spostamenti meccanici e i cicli di carico e scarico dell'ET durante i vari tentativi di lancio, quando l'ET è sottoposta a più operazioni con variazioni termiche da condizioni termiche da ambientali a criogeniche (e viceversa).
Nell'articolo che posto qui sotto riguardo lo spostamento del lancio alla seconda finestra di quest'anno, spiega molto bene tutto ciò. Le parti in grassetto sono quelle più interessanti, quella in corsivo è incentrata sul problema incontrato durante il lancio del Discovery a luglio.
Shuttle launch delayed to July 1 for tank sensor swap
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: March 14, 2006
The shuttle Discovery's launch on the second post-Columbia mission has been delayed to at least July 1 because of work to replace suspect engine cutoff - ECO - sensors in the ship's external tank. Shuttle program manager Wayne Hale made the decision Tuesday, after two days of detailed engineering discussions, even though the issue was not an open-and-shut case and even though the sensor in question may be good enough to fly. In the end, Hale decided to err on the side of caution in a bid to resolve, once and for all, questions about the sensors that have lingered since Discovery's launch on the first post-Columbia mission last July.
"This was not an easy decision," Hale told reporters late today. "We had quite an interesting debate, pros and cons, looked at every possible way around this and finally concluded it was far smarter for us to be conservative and to take the safe route and replace the sensors that are in the tank.
"That will take us about three weeks of work and that, of course, will move us out of the May launch window for STS-121. So today, we are proposing that the no-earlier-than launch date, the earliest possible launch date, would be July 1."
Discovery should be ready to fly well before the target date, but program managers want to launch the next two missions in daylight to make sure they can document how the foam insulation on the external tank performs.
It was the loss of a large piece of insulation that doomed Columbia in 2003 and the loss of another large piece of foam during Discovery's launch last July that has held up subsequent flights. NASA currently is conducting wind tunnel tests to make sure changes to the tank's insulation are safe and Hale said today he does not yet have enough data to make a final decision.
But assuming the foam modifications are good to go, Discovery must be launched in daylight for photo-documentation to verify the insulation's performance. Because the shuttle is flying to the space station, it must launch into the plane of the lab's orbit and that, coupled with a daylight launch constraint and other factors, limits when NASA can make a launch attempt. The next "window" opens July 1 and closes July 19.
"We, in fact, will be ready, we think, with the vehicle before July 1, but we are dedicated to launching in the daylight so we can watch what happens to the external tank and the rest of the flight vehicle during the daylight for at least two more flights, STS-121 and the subsequent STS-115," Hale said. "So we are aiming now for July 1."
The new launch date will give NASA time to resolve a variety of other challenging issues, including analysis of the foam modifications, what to do about main propulsion system (MPS ) contamination, what to do about MPS seals that may not meet specifications and recent damage to the shuttle's robot arm that could force NASA to use one taken from Endeavour. Given the launch delay, however, NASA may be able to fix Discovery's arm in time for launch in July.
The ECO sensors are located at the base of the hydrogen section of the shuttle's huge external tank. The sensors are part of a backup system intended to make sure the shuttle's three main engines shut down before they completely drain the tank. Running the tank dry could cause powerful turbopumps to cavitate and fail, with potentially catastrophic results.
The sensors use platinum wires whose electrical resistance depends on temperature. When the sensors are submerged in ultra-cold liquid hydrogen, resistance is extremely low. As the fuel level drops and the sensors become exposed, the temperature - and resistance - goes up. The change in resistance is monitored by a so-called point sensor box that, in turn, sends data to the shuttle's flight computers.
Sensors can "fail wet" or "fail dry." Failing in the wet state is considered relatively benign because the shuttle is launched with more propellant than it actually needs and because the sensors are, in essence, a backup system. If sensors fail wet, the engines would continue to run and the shuttle's computer system presumably would shut them down on time based on meeting orbital requirements. But if two sensors failed in a dry state, the computers would be misled into believing the tank was nearly empty and the main engines would be ordered to shut down early. Unless it happened extremely late in the climb to space, that could trigger a dangerous, untried abort scenario.
"Just like your car, you don't want to run it out of gas, that's not a good thing," Hale said. "You'd like to get where you want to go before the tank is completely empty. So the normal planning for a mission allows us to achieve the right orbital conditions - altitude, speed, direction of travel - without running out of propellant. In fact, we load extra fuel on board to make sure that even if we have small variations in the performance of the vehicle during launch, a small reserve is there to make sure we get to that point in the sky without running out of gas.
"The sensors are there in case we have some kind of performance problem, which we have had twice in the history of the program."
In one case - the launch of Challenger on mission STS-51F in July 1985 - a main engine shut down early because of an engine sensor problem, triggering an abort to a lower-than-planned orbit. As a result, the two remaining engines had burn longer than usual to make up the shortfall and the shuttle essentially ran out of gas below the desired altitude. The ECO sensors performed normally and forced engine shut down before the tank was completely dry.
The only other instance of ECO sensors playing a role in a flight came in 1999 during launch of the Chandra X-ray Observatory aboard the shuttle Columbia. Because of a hydrogen leak and an electrical short circuit, Columbia's tank was nearly drained and the ECO sensors, once again, came to the rescue.
"In both cases, the sensors, through the on-board computers, correctly told us that the tank was dry, we were out of fuel and we should shut the engines down," Hale said. "You like to shut the engines down with just a little bit of gas left in the lines to make sure those pumps, that pump the hydrogen and the oxygen into the engines, don't cavitate as they spin down. That's not good for the engines and it can lead to a number of problems, so we have in place these sensors on both the fuel side and the oxygen side."
During Discovery's launch campaign last year, however, the ECO sensor system experienced a variety of subtle problems. Engineers were never able to trace the issue to an obvious fault and in the end, shuttle managers opted to replace the fuel tank. Even then, problems remained, but engineers believed the only likely worst-case result would be one sensor failing wet. After a detailed analysis, they approved a plan to launch Discovery with three of four working sensors for a limited set of circumstances. As it turned out, all four sensors worked normally on launch day and Discovery's ascent was uneventful from an ECO sensor standpoint.
But NASA launched an extensive engineering evaluation that ultimately made a tentative connection between changes in the resistance of a sensor and possibly loose wiring leading to the detectors. And as it turned out, one sensor in Discovery's current tank - ECO-3 - showed a small two-ohm resistance shift during a test prior to shipment to the Kennedy Space Center.
The tank was shipped anyway because a sensor swap-out, if one was ordered, would be easier to carry out with the tank in a vertical position, something not possible at Lockheed Martin's Michoud Assembly Facility near New Orleans.
"During the course of this investigation over the last several months, they found that there may be a problem in the manufacturing of these sensors and that problem is in the way the wires are attached to these low-level sensors," Hale said. "There is a place that the wires attach to the sensors called a swage fitting. That swage fitting in some sensors that have been removed some time back in the history of the program have been noted to be a little loose and that's caused intermittent readings, varying resistance, in the sensor, which of course is how the sensor tells you whether it's reading a dry or a wet signal.
"Last year, when we prepared to launch STS-114, we had a high degree of confidence the sensors would only fail, if they were to fail, in the wet reading condition. There is now some body of evidence that would indicate it's possible for the sensors to read erroneously dry when the tank is not, in fact, dry. A predecessor indication that something may be going on in the sensors is a shift in the resistance over time, particularly after the tank has been transported, vibrated, rattled around a little bit.
"We, in fact, have a sensor in the external tank slated for the next flight that's showing a very small shift in its resistance reading, well within any previously established specification. However, because of the new knowledge we have this year and the ongoing engineering work that's looking at how these sensors work and how they may potentially have problems, we are taking the step of removing the external tank sensors from the bottom of the liquid hydrogen tank, from the tank we're going to use for the next space shuttle flight."
The current ECO sensors were manufactured in 1996. The new sensors were built in 2002 and are believed to be immune to the loose wiring/swage fitting phenomenon. Ultimately, Hale said, the ECO sensor decision was driven by safety and the need for engineering forensics, not schedule.
"This is what we call a criticality 1 (system), life-or-death kind of situation that you want those sensors to work properly, either way," he said. "They can prevent bad things from happening if they work properly and certainly, if they work badly they can cause bad things to happen. So we need to have a good set."
To replace the sensors, engineers from the Michoud Assembly Facility, working in the Kennedy Space Center's Vehicle Assembly Building, will remove foam insulation from the very bottom of the tank, unbolt a large manhole cover and get inside the cavernous hydrogen section. Once the new sensors are in place, the manhole cover will be bolted back in place and, after lowering the tank to a horizontal orientation, foam insulation will be re-applied.
"We hope to take the four sensors that we take out and put them in extensive tests," Hale said. "We want to see if the one sensor that's got this slightly elevated resistance reading really has this problem that the engineering tests say it could potentially have and then, of course, we will look at the other three sensors which were manufactured about the same time in the same facility.
"We have a number of these sensors in tanks that are still slated to fly. The sensor in question was made 10 years ago, in 1996, and passed all its acceptance tests."
The additional six weeks of work "should provide us plenty of time" to wrap up ongoing analysis of foam modifications, as well as a variety of other issues, including what to do about contamination on a liquid oxygen filter screen leading to one of the ship's main engines and questions about critical seals between the engines and the main propulsion system plumbing.
"I think we'll be in good shape to look forward to a launch about the first of July," Hale said. "I remain optimistic we'll still be able to get three missions in this year, but I don't have the details on where we will fly the next two missions. Later in the fall, I'm sure."
Dave (uno degli "insider" al KSC - lavora come ingengere per uno dei contractors della NASA, la United Space Alliance, unione dell'ex-Rockwell, poi acquisita dalla Boeing, e della Lockheed-Martin, che hanno progettato e costruito l'orbiter), aggiunge qui (http://uplink.space.com/showflat.php?Cat=&Board=missions&Number=342791&page=0&view=collapsed&sb=5&o=0&fpart=12) una nuova informazione a proposito:
The Launch Commit Criteria was 3 of 4 good required at the time of the Final Challernger launch. As part of the post accident reviews that was changed to 4 of 4 to launch
Dai, non mi sbagliavo del tutto :D
Grazie GioFX per le delucidazioni! ;)
Dai, non mi sbagliavo del tutto :D
Grazie GioFX per le delucidazioni! ;)
Scusa non volevo contraddirti. Il no non c'entra :D
qualcuno puo dirmi quale sarà l'obiettivo della sts-115?
e per la iss quando saranno aggiunti nuovi pezzi, nn ci sto a capir niente :(
Scusa non volevo contraddirti. Il no non c'entra :D
Tranqui! :D
Tornando in argomento, metteranno i sensori fatti nel 1996 o quelli del 2002?
qualcuno puo dirmi quale sarà l'obiettivo della sts-115?
e per la iss quando saranno aggiunti nuovi pezzi, nn ci sto a capir niente :(
La missione STS-115 sara' la prima dopo le due "return to flight", e, come tutte le missioni dalla 115 in poi saranno dedicate all'assemblaggio della stazione spaziale internazionale. Solo una potrebbe essere dedicata alla manutenzione dell'Hubble.
Atlantis' primary launch processing is for STS-115, which is now due to launch on July 1. Atlantis' launch will see the re-start to ISS (International Space Station) assembly missions, adding the P3/P4 Truss to the outpost.
STS-121 (ULF1.1) OV-103 RTF NET May 3, 2006
STS-115 (12A) OV-104 Trusses P3/P4 NET July 1 (CSCS launch NET June 15
STS-116 (12A.1) OV-105 Space Hab, Truss P5 and ICC NET Oct. 01
STS-117 (13A) OV-104 Trusses S3/S4 NET Dec. 7
STS-118 (13A.1) OV-105 Space Hab and Truss S5 NET March 15, 2007
STS-119 (15A) OV-103 Truss S6 NET May 03
STS-120 (10A) OV-104 Node 2 NET June 14
ovviamente le date slitteranno tutte per il ritardo della missione STS-121, ma questo era il programma di massima..
(ho preso spudoratamente pezzi dei post precedenti di GioFX :cool: )
ah grazie e la prossima quindi, la 121 che dovrà fare?
qualcuno puo dirmi quale sarà l'obiettivo della sts-115?
e per la iss quando saranno aggiunti nuovi pezzi, nn ci sto a capir niente :(
L'STS-121 è la seconda ed ultima missione del Return To Flight, in cui verranno testeste altre tecniche per l'ispezione (con telecamere e laser) del TPS (Thermal Protection System), in particolare questa volta utilizzando una versione modificata del braccio robotico dello Shuttle per controllare la parte inferiore dell'orbiter.
Oltre a questo l'STS-121 è una missione logistica, con l'invio di ricambi e hardware per gli esperimenti, utilzzando l'MPLM (Multi Purpose Logisti Module) Leonardo, costruito dall'Alenia (come Donatello e Raffaello).
La costruzione dell'ISS riprende (senza più eccezioni, tranne la Servicing Mission 4 dell'HST nel 2010), appunto, con l'STS-115 prevista al momento per l'estate, con i segmenti P3 e P4.
Il programma è questo al momento:
2006
1 – May 10 – STS-121 – ULF1.1 – Discovery – MPLM Leonardo
[August 4 – STS-300 – CSCS for STS-121 – Atlantis]
2 – August 28 – STS-115 – 12A – Atlantis – P3/P4
[October 28 – STS-301 – CSCS for STS-115 – Endeavour]
3 – November 16 – STS-116 – 12A.1 – Discovery – P5 & Spacehab-SM
4 – December 7 – STS-117 – 13A – Atlantis – S3/S4 (possible postponing to 2007)
2007
5 – March 15 – STS-118 – 13A.1 – Endeavour – S5 & Spacehab-SM
6 – May 3 – STS-120 – 10A – Discovery – Node 2
7 – June 14 – STS-122 – 1E – Atlantis – Columbus
8 – August 23 – STS-123 – Endeavour (possible ULF2 with MPLM Leonardo)
9 – October 11 – STS-124 – 1J – Discovery – JEM PM Kibo
10 – November 29 – STS-119 – 15A – Atlantis – S6
2008
11 – February 7 – STS-125 – HST-SM4 – Endeavour
12 – April 3 – STS-126 – Discovery (possible 17A with MPLM Donatello)
13 – May 22 – STS-127 – 2J/A – Atlantis – JEM EF Kibo
14 – July 3 – STS-128 – Endeavour (possible UF3 with MPLM Donatello; the 6 person ISS crew is established with this flight)
15 – October 2 – STS-129 – Discovery (possible UF4 with Express 1 & AMS-02)
16 – December 4 – STS-130 – Endeavour (possible 19A with MPLM Donatello)
2009
17 – March 19 – STS-131 – CLF – Discovery
18 – May 14 – STS-132 – 20A & 14A – Endeavour – Node 3 & Cupola
19 – August 20 – STS-133 – CLF – Discovery
**Flights 17 and 19 under review as CLFs (Contingency Logistic Flight)
Il manifest ufficiale NASA lo trovate qua:
http://www.nasa.gov/mission_pages/station/structure/iss_manifest.html
Tranqui! :D
Tornando in argomento, metteranno i sensori fatti nel 1996 o quelli del 2002?
2002, gli utlimi costruiti, sulla base delle più recenti specifiche.
ah grazie e la prossima quindi, la 121 che dovrà fare?
http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts121/index.htm
ma i pezzi della iss vengono mandati solo dagli USA? l'esa e la russia che ruolo hanno?
ma i pezzi della iss vengono mandati solo dagli USA? l'esa e la russia che ruolo hanno?
si altrenano per determinati anni!
tant'è vero che quando è successo il disasto dello shuttle la russia era l unica a rifornire la iss
e il prossimo lancio della soyuz del 29 marzo che farà?
ma i pezzi della iss vengono mandati solo dagli USA? l'esa e la russia che ruolo hanno?
quasi tutto l'hardware è stato o sarà lanciato con lo Shuttle, per semplici motivi già ricordati nel thread sulla ISS: solo lo shuttle può trasportare i moduli più grossi, i segmenti e i pannelli solari. Questo perchè il vano di carico (payload bay) è più largo di qualsiasi lanciatore espandibile, e per il tonnellaggio lanciabile.
I moduli russi (Zarya e Zvezda) sono stati lanciati con i Progress (infatti sono più piccoli in larghezza), mentre gli equipaggi con lo shuttle e il Soyuz.
Dal 2007 l'ESA si aggiungera con l'europeo ATV, dotato di navigazione autonoma ed attracco automatico) per il trasporto di rifornimenti e logistica. Dal 2009 anche l'analogo giapponese HTV.
e il prossimo lancio della soyuz del 29 marzo che farà?
Trasporta i 3 astronauti della 13 spedizione.
scusatemi, ma nn ho capito cosa sostituirà gli shuttle...
tnx
scusatemi, ma nn ho capito cosa sostituirà gli shuttle...
tnx
Sara' il CEV (Crew Exploration Vehicle)
se ne parla qui:
http://www.hwupgrade.it/forum/showthread.php?t=1020181
da Spaceflightnow.com (http://www.spaceflightnow.com)
Tank foam lost during shuttle wind tunnel test
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: April 13, 2006
During wind tunnel tests earlier this week, NASA subjected a full-scale mockup of a shuttle external tank section to aerodynamic forces greater than a real tank would experience during launch. In one series of tests, unmodified foam insulation used to prevent ice buildups around external fittings suffered only minor damage while a redesigned "ice/frost ramp" suffered major foam loss.[...]
The ice/frost ramps were partially shielded from aerodynamic buffeting by the now-removed PAL ramps and questions were raised about whether the old ramp design could stand up to launch forces. In one set of runs at Tullahoma, the original design suffered only minor damage, sources said. But in two sets of tests using the redesigned ice/frost ramps, large chunks of foam blew off. It's not yet clear what caused the failures and more tests are planned.
l'intero articolo:
http://www.spaceflightnow.com/shuttle/sts121/060413update/
Cmq è certo che se i test confermeranno come pare che l'ET può volare senza la PAL ramp, il lancio non subirà altri ritardi (esclusi altri problemi, ovviamente).
un aggiornamento/approfondimento sulle verifiche aerodinamiche dell l'External Tank:
http://www.spaceflightnow.com/shuttle/sts121/060428icefrost/
P.S. Si va abbastanza in dettaglio sull'argomento..specie sui fattori di rischio.. :rolleyes:
Speriamo trovino a breve la soluzione ottimale
Da Spaceflightnow.com (http://www.spaceflightnow.com/shuttle/sts121/060504notanktest):
Shuttle managers decide against special fueling test
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: May 4, 2006
NASA managers today ruled out a June 1 fueling test with the shuttle Discovery, deciding there was no clear-cut technical justification for a complex exercise that would put unwanted stress on the tank's foam insulation and use up valuable contingency time.
Shuttle program manager Wayne Hale ordered engineers to make tentative plans for a tanking test earlier this spring as a way to make sure recently replaced engine cutoff - ECO - sensors would work properly on launch day.
The test would not have included any so-called "drag on" instrumentation in the shuttle's aft compartment and its sole purpose would have been to verify the ECO sensors changed state from dry to wet and back again as expected. In the absence of additional instrumentation, no detailed operational insights would be possible.
During a weekly program meeting today, the management team unanimously decided not to run the test, officials said, because any major problems with the ECO sensors almost certainly would preclude a launch in the July window anyway and because loading the tank with supercold propellant would subject its foam insulation to unwanted thermal stress.
Shuttle tanks are certified for 13 fueling cycles. When a countdown proceeds past the point where the tank is pressurized for launch - part of the plan for the June test - it counts as two cycles.
Discovery's launch on the second post-Columbia mission is targeted for July 1. The ECO sensors will be checked, as usual, when the tank is loaded with liquid hydrogen and oxygen on launch day.
The ECO sensors are part of a backup system intended to make sure the shuttle's three main engines don't shut down early or run too long. All four hydrogen ECO sensors are required to be operational for launch, but NASA managers could waive that requirement in certain narrowly defined cases depending on whether a given sensor failed in the wet or dry state.
But any major ECO sensor problems, whether they occurred June 1 or July 1, almost certainly would rule out a launch before the window closes July 19. The engineering community believes all four sensors currently installed will work properly.
Engineers currently plan to move Discovery from its processing hangar to the Vehicle Assembly Building for attachment to the tank and its twin solid-fuel boosters on May 12. Rollout to the launch pad is targeted for May 19.
Rollover could be briefly delayed if engineers decide to correct a subtle timing problem with a recently installed jet thruster control assembly. But with the elimination of the tanking test, the Kennedy Space Center launch team has 17 days of contingency time available to handle unexpected problems.
The engineering community is still assessing the overall safety of the external tank without foam wind deflectors called protuberance air load - PAL - ramps. The ramps were removed following the loss of foam debris from the hydrogen PAL ramp of the tank used by Discovery during the first post-Columbia mission last July.
A final analysis of the tank's ability to withstand aerodynamic buffeting without the ramps in place, based on wind tunnel testing and complex computer modeling, is expected next month.
Space shuttle Discovery makes trek to launch pad
Discovery has arrived at pad 39B for its planned July 1 liftoff on the second post-Columbia space shuttle test flight. Friday's rollout from the Vehicle Assembly Building took eight hours to complete.
http://www.spaceflightnow.com/shuttle/sts121/status.html
http://www.nasa.gov/mission_pages/shuttle/main/index.html
Hale says 'rough cut' wind tunnel data is positive
Shuttle program manager Wayne Hale, on hand for Discovery's rollout to launch pad 39B Friday, said a preliminary look at complex wind tunnel data shows the ship's redesigned external fuel tank should be safe to fly in July. While stressing that a detailed analysis of the data is ongoing and saying new problems could always crop up, "the preliminary loads indications are good, but we have to wait until they get to the bottom line."
http://www.spaceflightnow.com/shuttle/sts121/060519rollout/
SpaceFlightNow.com:
Discovery passes launch debris review for July liftoff
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: May 31, 2006
After a "spirited" two-day review, NASA managers today concluded the agency has reduced the threat of catastrophic damage from external tank foam and other debris to an acceptable level, a major milestone on the road to clearing the Discovery for launch July 1 on the second post-Columbia shuttle mission.
http://www.spaceflightnow.com/shuttle/sts121/060531tankdvr/discoveryonpad.jpg
Credit: NASA-KSC
"We have found no show stoppers. We believe we have made significant improvements since last year in the elimination of many of the hazards from foam," said shuttle program manager Wayne Hale.
"But one of the things I don't want to hear when I go home and turn on the TV tonight is that we've fixed the tank and no foam is going to come off. Because that is not the case. ... There will continue to be foam coming off the external tank. What we have done in a very systematic manner is eliminate the largest hazards." But an earlier decision by NASA Administrator Michael Griffin, Hale and other senior agency managers not to change the way foam is used to insulate 34 critical brackets on the skin of the tank means Discovery will be launching with insulation that could, in a worst-case scenario, cause the very sort of catastrophic damage NASA has been struggling to prevent.
While today's Debris Verification Review, or DVR, did not generate any formal probabilities regarding the actual threat posed by ice/frost ramp "foam shedding," Hale said he believes the IFR foam should be listed in a threat matrix as "probable/catastrophic," meaning that over the life of the shuttle program, debris from the bracket insulation, in a worst-case scenario, could lead to a disaster.
Even so, Hale believes NASA is justified in pressing ahead with near-term shuttle flights while engineers devise a bracket redesign that eventually will allow them to remove the ice/frost ramp foam altogether. While the IFR foam represents a clear long-term threat, the risk on any given flight is in line with dangers posed by other systems.
"With the very worst-case assumptions, there were some numbers down as low as 1-in-75 and for some of the better-case assumptions, you're talking about numbers on the order of 1-in-400 for ice/frost ramp foam losses," Hale said.
"I hate to quote probability numbers without context because it depends so much on what the assumptions were and how conservative or how fine the calculations were that went into the case. But we're talking, basically, something on the order of 1-in-a-few hundred, or 1-in-100, which is consistent with the entire overall risk we fly with the space shuttle."
During Discovery's launch last year on the first post-Columbia mission, a one-pound chunk of foam insulation broke away from a long wind deflector known as a protuberance air-load - PAL - ramp on the tank. The PAL ramps, one on the oxygen section and one on the hydrogen section of the tank, were designed to shield two pressurization lines and a cable tray from aerodynamic buffeting.
While the PAL ramp debris lost during Discovery's flight didn't hit anything, NASA managers ultimately decided to remove the ramps on the assumption computer modeling and wind tunnel tests would show the pressurization lines and cable tray are tough enough to endure the ascent environment.
http://www.spaceflightnow.com/shuttle/sts121/060531tankdvr/discoveryrollout.jpg
Ben Cooper/Spaceflight Now
A design certification review to formally assess the results of testing and to officially sanction the flight worthiness of the new design should be finished in time for Discovery's flight readiness review June 16 and 17.
This week's DVR was concerned primarily with foam debris and any other sources of potential impact damage to the orbiter.
The external tank pressurization lines are supported by 34 brackets on the skin of the tank that are insulated by up to two pounds of foam each. The insulation is needed to prevent ice from building up on the brackets when the tank is loaded with supercold rocket fuel. Any such ice would pose an impact threat during launch.
Along with removing the PAL ramps, engineers wanted to reduce the amount of foam used on the brackets, and thus minimize the debris impact threat from that quarter.
But during wind tunnel testing earlier this year, an ice/frost ramp redesign option fared worse than the original design. Rather than race to make yet another major change in the tank, NASA managers opted to accept the risk and to fly the ramps as is until a more robust redesign could be developed.
"We think they are a hazard, I want to make that very clear, they are an area of foam insulation that we very definitely need to deal with," Hale said today. "But the principle that we have to remember, however, is that in a flight test, you want to make one major change at a time, instrument it, fly it and see how that performs before you make another major change.
"So we're going to fly this flight with a major improvement - the elimination of the PAL ramp - but we know we have another hazard that we also need to eliminate, and that will be the elimination of the ice/frost ramps as quickly as we can come up with a good design option. So we put them right at the top of our risk matrix. That's the number one thing we have to work on next."
No such risk matrix has been formally approved for Discovery's flight.
"Basically, this vehicle, and you can take this to the bank, is about a 1-in-100 vehicle," he said. "It is a risky vehicle to fly. And nobody should mistake that, there are a number of things that can cause bad outcomes in this vehicle. What we've tried to do is take a very serious look at every one of the areas that we think are higher risk and do our best to mitigate those."
Columbia was brought down in 2003 by a 1.6-pound piece of foam insulation from an area of the tank known as a bipod ramp. The PAL ramp foam that broke free during Discovery's launching last July weighed about one pound. The largest documented piece of ice/frost ramp foam shedding amounted to about 0.09 pounds. Engineers believe, however, up to 0.2 pounds - about three ounces - is possible.
Removing the PAL ramps eliminated about 34 pounds of foam. Engineers hope to implement an incremental ice/frost ramp upgrade, first using insulators to allow the removal of some foam and ultimately by using different bracket material, possibly titanium, to achieve the same insulating effects without any foam at all.
Hale said the interim fix using insulators might be available three or four tanks down the road. Complete elimination of foam will take longer.
"Today we have a tank on the pad that has lost 34 pounds, the largest amount of foam that we've ever taken off the tank, to reduce the hazard," Hale said. "We have put on a special set of sensors, both accelerometers and force measurements on that tank, as well as a suite of six new cameras on the solid rocket boosters that will be monitoring the performance of the vehicle during ascent to ensure that we have done our job properly in the removal of that protuberance air-load ramp. But we do expect to see foam come off."
Da SpaceFlightNow.com:
Discovery's fuel tank receives certification
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: June 7, 2006
NASA managers today cleared the shuttle Discovery's external fuel tank for flight based on wind tunnel data and computer modeling that show the huge tank can stand up to the aerodynamic rigors of launch despite the recent removal of long foam wind deflectors. Launch currently is targeted for July 1, at 3:48 p.m., but the long-awaited flight could slip another day or so to ensure better lighting for critical photography of the tank after Discovery reaches orbit. NASA managers are expected to discuss the lighting issue during a weekly review Thursday.
Discovery's launch window is defined, in part, by a requirement to launch in daylight and to have the external tank separate from the orbiter in daylight, half a world away. The goal is to obtain good photos of the tank's redesigned foam insulation as well as the shuttle's heat-shield tiles and wing leading edge panels to spot any potential impact damage.
As it turns out, a new analysis of orbital lighting conditions shows a camera mounted in the belly of the shuttle will not have enough light for good photography if Discovery takes off July 1. Conditions improve on July 2 and subsequent days.
Even then, lighting is not expected to be acceptable for crew handheld still and video photography until around July 5. But the critical driver is the umbilical camera, which is positioned to provide good views of foam ramps around external fittings on the tank that carry pressurization lines.
Those so-called ice/frost ramps have not been modified. But long protuberance air-load - PAL - ramps that provided some aerodynamic shielding for the pressurization lines and a critical cable tray, were removed in the wake of major foam shedding during Discovery's launch last July on the first post-Columbia mission.
Shuttle program manager Wayne Hale approved removal of the PAL ramps on the assumption wind tunnel data and computer modeling would show the pressurization lines, cable tray and other fittings will stand up to increased aerodynamic buffeting during the climb out of the lower atmosphere.
During a meeting at Lockheed Martin's external tank assembly facility near New Orleans today, shuttle managers concluded the PAL ramp-free tank has enough of a margin of safety to endure even worst-case aerodynamic loads.
The results of the certification meeting, which focused on the removal of the PAL ramps and modifications to prevent foam shedding near the bipod that attaches the shuttle's nose to the tank, will be presented at a formal flight readiness review June 16-17 at the Kennedy Space Center.
Discovery's crew, meanwhile, flies to the Florida spaceport June 12 for launch site emergency drills and a dress-rehearsal countdown June 15.
Spaceflightnow.com:
Shuttle launch date set despite safety objections
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: June 17, 2006
NASA Administrator Mike Griffin, overruling objections from the agency's chief engineer and safety office, cleared the shuttle Discovery for launch July 1 on a mission to service and resupply the international space station. The flight also will clear the way for the resumption of station assembly later this fall and deliver a third full-time crew member to the international outpost.
http://www.spaceflightnow.com/shuttle/sts121/060617july1/frr.jpg
This is a view inside the Flight Readiness Review that set July 1 as Discovery's official launch date. Credit: NASA-KSC
The objections centered on the risk posed by launching Discovery with foam buildups around brackets on the ship's external tank that are now formally classified as "probable/catastrophic" in NASA's integrated risk matrix. That means it is probable that the so-called ice-frost ramps will shed debris with catastrophic results over the life of the program.
Griffin told reporters today he did not agree with the probable/catastrophic classification and added that even in a worst-case scenario, the astronauts would not be in immediate danger. Because of new cameras and other sensors, any damage would be seen and the crew could either attempt repairs or move aboard the space station to await rescue by another shuttle crew.
Throwing in broader programmatic issues, including a presidential directive to finish the station and retire the shuttle fleet in 2010, Griffin said he decided it made more sense to resume shuttle flights now, with the current ice-frost ramps, and to implement a redesign as soon as possible.
Insisting safety remains his top priority, Griffin left no doubt about the stakes involved. Losing another space shuttle - even if the crew survived - will mean the end of the program.
"If we were to lose another vehicle, I would tell you right now that I would be moving to figure out a way to shut the program down," he said. "I think at that point, we're done. I'm sorry if that sounds too blunt for some, but that's where I am. We're trying to navigate some very difficult waters ... to get the station assembled. I think that's worth doing. I've stated that on multiple occasions, but it's not easy."
Griffin's comments came at the end of a two-day flight readiness review at the Kennedy Space Center where top agency managers and engineers gathered to review Discovery's flight processing. The debate about the classification of the ice-frost ramps in NASA's integrated risk matrix stirred a fair amount of debate. NASA's chief engineer and safety manager both said that if the ice-frost ramps were classified "probable/catastrophic" they were no-go for launch. The majority of those attending the FRR disagreed and voted to proceed with the flight. The final decision was Griffin's.
Because of the unique nature of this debate, and because of the high stakes involved, here is Griffin's complete answer to a question from CBS News to explain his rationale:
"I'm not concerned with what box in the matrix we're in because that's a matter of terms and definitions," he said. "In point of fact, I don't agree with the way that we categorized that risk as being 'probable.' Because if it's going to be 'probable,' then that means that over some reasonable span of flights I would expect to see evidence of that behavior. We can as statisticians go off and argue about what percentage of the time you expect to see it, but if we say 'probable,' we mean that over some reasonable span of activity we should see it. And I won't at this point refine it further.
"Now, in fact, we have 113 flights (sic) with this vehicle with these ice-frost ramps under our belt. And while we've had two loss of vehicle incidents, they've not been due to ice-frost ramps. So I have a great deal of trouble believing that a statistically sound statement would be to say that this is a 'probable' event to be seen over the next 16 flights. I just have trouble with that.
"Now without regard to the label, getting past the label, the concern then is do we, in fact, think that if we fly this ice-frost ramp the way it is for some very small, not 16, but some very small number of flights, a few, until we have a better design - and let me be the first to lead the parade saying we've got to have a better design, we want to know that it's a better design and we want to take our time with it - so the question is, can we fly a few times with this ice-frost ramp without probably incurring a hazard? And based on the data I have seen, I believe that we can.
"I believe that our models are quite conservative, I believe that our models have a huge variance in them, we really don't know as much about these phenomena as we would like to. Because if we believed our models, we would believe that we had a worse problem than our flight data is showing, which is a red flag to indicate that we don't understand as much as we would like to understand. We need to continue to be hungry, we need to continue to dig out the information the vehicle is telling us. But we need to fly it to dig it out.
"So how do I justify that? With as much uncertainty as we have, I ... certainly would have to think harder about putting a crew on this vehicle if I thought they didn't have the space station safe haven option and the launch-on-need (rescue flight) option and for that matter, if push came to shove, to call up Russian Soyuz spacecraft for rescue. I do not see the situation we're in as being a crew-loss situation.
"If we are unlucky and we have a debris event on ascent, it will not impede the ascent, the crew will arrive safely on orbit and then we will begin to look at our options, whether those include repair, launch on need, extended safe haven on the station, asking our Russian partners for help, maybe some or all of the above. We will have decisions to make, but we will have time to make those decisions. We are not in the situation that we were in with Columbia where we didn't know that we had a problem. We'd know we have a problem, we have elected to take the risk, we do not believe we are risking crew.
"There is a programmatic risk, without doubt. If we have another major incident in launching the space shuttle, I would not wish to continue with the program. We're going to use this flight and the subsequent flights to complete the space station, that's what we want to do with the shuttle, within the next three years we're going to complete the space station. We believe it is possible to do so. But if it is going to be possible to do so, we're going to have to take some programmatic risks because the shuttle will be retired in 2010.
"This president's budget will not carry funding for shuttle vehicles beyond 2010. So if we're going to fly, we need to accept some programmatic risk and get on with it. Again, I'll point out, for me to accept programmatic risk to do this is not the same as accepting a crew risk, which we believe we're not doing."
In shuttle program manager Wayne Hale's view, NASA already is accepting a fair amount of risk based on an earlier decision to remove so-called protuberance air-load - PAL - ramps from the tank in the wake of a major foam shedding incident during Discovery's last flight a year ago.
The PAL ramps were in place to shield external pressurization lines and a critical cable tray from aerodynamic buffeting as the shuttle climbs out of the dense lower atmosphere. The pressurization lines are held in place by 34 brackets that are covered in foam insulation - ice-frost ramps - to prevent potentially dangerous ice formation before launch.
Wind tunnel testing and computer modeling have convinced managers the tank and its external lines and fittings are tough enough to stand up to the stresses of launch without the PAL ramps. But NASA does not yet have a redesign in place for the ice-frost ramps, which now represent the most potentially dangerous concentrations of foam on the tank.
Engineers had hoped to implement a redesign before Discovery's flight, but wind tunnel testing showed the proposed change fared worse than the old design. As a result, Griffin, Hale and other senior agency managers agreed earlier this spring to stick with the old design for the next few shuttle flights while another redesign is perfected.
After an extensive debris verification review May 31, Hale said he agreed the ice-frost ramp foam should be listed in the risk matrix as probable/catastrophic. But he said NASA was justified in pressing ahead with near-term shuttle flights while engineers devise a bracket redesign that eventually will allow them to remove the ice-frost ramp foam altogether. While the IFR foam represents a clear long-term threat, the risk on any given flight is in line with dangers posed by other systems.
Hale said today the "probable/catastrophic" classification reflected his belief "as program manager those issues need to be elevated to senior NASA management for their review and disposition. I believe they are at an unacceptable level for the program manager to take that risk on by himself."
Even so, Hale said he believes the ice-frost ramps are "an acceptable risk" when viewed from a broader agency perspective.
"I recommended to the administrator and (spaceflight chief) Bill Gerstenaier that even though we did rate these very high, I think it is acceptable for a number of reasons to go fly for a limited number of flights while we come up with the redesign," Hale said. "So that's where we rated it. I will tell you that it was an interesting discussion."
Gerstenmaier said the debate marked "a difficult situation because we have data that shows we have potentially cracks underneath large foam or foam that's put on top of other foam. And we have flight history that doesn't show that we lose a lot of foam. ... So the dilemma is, how can we not rule out that at some point in the future we're not going to have some larger foam loss with this underlying problem? And therein lies the debate.
"We can't figure out the theory that can explain to us why we haven't had larger foam loss," he said. "Obviously, there's something we think that's protecting us in the physics of the situation, but we don't know what that is. What we discussed as an engineering team are what the pros and cons of that are, we looked at statistical models, we looked at transport models, we looked at all of this as a team. ... There wasn't a united engineering position on this.
"We laid out our rationale for the decision to go fly and really, no one objects to the decision to go fly," he said. "Both the safety office and the chief engineer, their point was they recommend being no-go but they don't object to us going to fly. ... The problem is, without understanding this underlying failure phenomenon, any fix we put on has some risk associated with it of losing foam or generating ice. We can control that as much as we can through design, but we can't eliminate that. So in a sense, we almost need to go fly to gain some more data."
Asked again by CBS News to explain how senior managers could cast a no-go vote in the FRR and yet say they agreed with launching Discovery anyway, Griffin made another attempt to explain the flight rationale.
"Some of the senior NASA individuals responsible for particular technical areas expressed that they would rather stand down until we had fixed the ice-frost ramp with something better whereas many others said no, we should go ahead," Griffin said. "So we didn't have unanimity. Therefore, a decision had to be made.
"We annunciated a careful rationale for flying that I believe mitigated the concerns that were expressed by the Office of Safety and Mission Assurance and by the office of the chief engineer. And in fact, they agreed with that. I don't want to say there's no ascent risk. There's plenty of ascent risk on the shuttle. Debris shed from the tank does not pose an ascent risk for the shuttle. OK? It poses a risk for entry.
"Since we have inspection methods, we are beginning to converge on some rudimentary repair methods, since we have the station for a safe haven, since ... we've got an excellent capability for launch on need and we have the Russian partners, we have a number of mitigation strategies should the unlikely occur and we have a debris strike. Subject to those conditions, the chief engineer and office of safety and mission assurance were OK with launch.
"Looking at their specific discipline areas, they would recommend that we stand down. But there are larger considerations. If we stand down, now we back up station assembly flights. One of the areas that surfaced during the CAIB (Columbia Accident Investigation Board) investigation was the issue of schedule pressure on NASA. Now schedule pressure for us is a fact of life, but it has to be balanced. I do not want to make decisions today which are going to result in having all the schedule pressure in creating station assembly in the last year or two. I don't want to get us into a situation where by being more cautious than I think technically necessary today, we wind up having to execute six flights in the last year or something. That's not smart.
"So I'm willing as administrator, looking at the whole picture, I'm willing to take a little bit of programmatic risk now - and notice I did not say crew risk - I'm willing to take some programmatic risk now in order to prevent an excessive buildup of programmatic risk later on. This is, in fact, what you pay me to do. The chief engineer and the Office of Safety and Mission Assurance are not paid to worry about schedule risk four years in the future, they're paid to worry about what is the situation with this particular flight. We had their input. In fact, both of them are long and valued friends of mine and people whom I have nothing but the greatest technical respect for. That goes without saying. But I cannot possibly accept every recommendation which I am given by every member of my staff, especially since they don't all agree.
"I don't know how to say it any more clearly, I'm sorry. I'm really doing the best I can here."
Discovery's countdown to launch on the 115th shuttle mission is scheduled to begin at 5 p.m. EDT on June 28. Liftoff is targeted for 3:48:15 p.m. on July 1.
..quella che ha preso Hale per uscire dall'impasse e portare a termine il programma Shuttle. :mbe:
spaceflightnow:
Hale says no pressure due to 2010 shuttle deadline
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: June 20, 2006
Shuttle program manager Wayne Hale played a direct role in classifying ice-frost ramps on the shuttle's external tank as "probable/catastrophic," but he told CBS Radio today his primary intention was to elevate the issue to a level that would ensure it received the proper attention.
During a two-day flight readiness review Friday and Saturday, NASA's office of Safety and Mission Assurance and the office of the chief engineer voted to delay Discovery's July 1 launch until the ice-frost ramps could be redesigned to minimize foam shedding.
A classification of probable/catastrophic in NASA's risk matrix means that over the remaining life of the shuttle program, it is probable foam will separate from an ice-frost ramp and cause catastrophic impact damage to the shuttle's heat shield.
NASA Administrator Mike Griffin, saying he did not believe the foam ramps posed such a high level of risk, decided to press ahead with space station assembly while a tiger team of engineers works on a new design.
The decision has generated attention because of Griffin's acknowledgement that schedule pressure - or more properly the threat of schedule pressure later in the station assembly sequence - played a role in his decision to clear Discovery for flight. All sides agreed the ice-frost ramps do not pose a direct threat to the astronauts.
"We had a full, open and public debate, airing all the opinions, looking at all the data," Hale told CBS Radio today. "Part of the story that perhaps hasn't been quite widely reported is how many folks came forward and said this is not as critical a hazard as you might think it is and we certainly have a good safety margin to go fly.
"As program manager, I listened to all sides of this and came down with the decision that we should rate this as a (probable/catastrophic) hazard, perhaps more dangerous than it actually is, in order to remind ourselves that we need to go continue to make improvements on the external tank.
"So that part got widely reported, I'm happy to hear, but the other side, that we are making steady improvements, that this is widely, much better understood than it was before and it has been widely aired and debated without any suppression of evidence or discussion, is a sign that the new NASA is willing to engage in these debates and, in fact, face problems head on rather than sweeping them under the rug."
Hale said he personally did not feel under any sort of pressure to launch Discovery or any other shuttle because of a looming 2010 deadline to finish station assembly and retire the shuttle fleet.
"Frankly, I do not feel the schedule pressure that everyone's speculating about," he said. "We have clearly demonstrated in the past that we've been able to fly the kind of flight rate that would lead us to assemble the international space station by 2010 with comfortable margin. So I feel very low schedule pressure to get off the pad, at least from that standpoint."
But Hale said the public should understand the risks involved with any shuttle flight. Even though the ice-frost ramp concern is not a direct threat to crew survival - the astronauts could move into the space station to await rescue in a worst-case scenario - NASA is "betting the program" every time the shuttle flies.
"We gamble the program every time we launch the vehicle in a thousand ways, many of which may be obscure to folks, but we take a calculated risk," he said. "I think NASA, by the way, is about the only federal agency that does sort of put the whole agency on the line every time we do our normal business. And we do it in public and we do it with a great deal of discussion with the public.
"But we do recognize the fact, and always have, that we bet the entire agency, the entire space program, every time we try to launch a rocket."
Countdown to Launch
http://www.nasa.gov/images/content/151083main_firingroom2.jpg
Image above: NASA Test Director Ted Mosteller (left) briefs the media about Firing Room 4, which has been undergoing renovations for two years. The new launch control center is now designated the primary firing room for all remaining shuttle launches. Photo credit: NASA/Dimitri Gerondidakis
Countdown for the launch of Space Shuttle Discovery begins at 5 p.m. EDT Wednesday, June 28, at the T-43 hour. Included in the countdown is nearly 28 hours of built-in hold time prior to a targeted 3:49 p.m. EDT launch on Saturday, July 1, with a launch window that extends for about five minutes. The launch countdown will be conducted from the newly renovated Firing Room 4 of the Launch Control Center at NASA's Kennedy Space Center in Florida.
NASA TV will provide live coverage of two exciting events on Tuesday, June 27. At 8:54 a.m. EDT, Expedition 13 Commander Pavel Vinogradov and Flight Engineer Jeff Williams will discuss their flight and the preparations being made at the International Space Station for the arrival of the STS-121 mission crew on Discovery.
At around noon EDT Tuesday, the crew of Discovery is expected to arrive at Kennedy. Commander Steven Lindsey will have an opportunity to speak briefly to the media about the mission.
The STS-121 crew includes Lindsey, Pilot Mark Kelly and Mission Specialists Michael Fossum, Lisa Nowak, Stephanie Wilson, Piers Sellers and Thomas Reiter, an astronaut with the European Space Agency. Reiter will remain with the Expedition 13 crew on the station.
NASA TV (http://www.nasa.gov/multimedia/nasatv/index.html)
Da NASAspaceflight.com:
NASA extends rescue missions on manifest
By Chris Bergin, 7/13/2006 10:37:00 AM
The latest Shuttle manifest shows NASA has extended the number of flights that will have a LON (Launch On Need) rescue mission on standby.
While STS-121 with Discovery has stood down its STS-300 LON (with Atlantis), three more rescue missions have been added to accompany flights through to at least STS-120, with another special - and very different - LON mission being considered for STS-125's Hubble Servicing Mission.
While this may come as a surprise, the remaining 16 missions yet to fly before the retirement of the Shuttle fleet allows for no major changes in the currently launch processing flows. Should, in the undesirable scenario of an orbiter being unable to re-enter, the next schedule mission should be able to provide LON assistance via its own regular timelines.
Most of all, the revalation of LON missions being added to the manifest should be seen as a sign NASA is not taking any chances.
Other than the additions of the LON missions, the manifest remains solid - and now realistic - following the successful 'clean' launch of Discovery last week.
The faster-than-scheduled change-out of the ECO (Engine Cut Off) sensors in ET-118 has pulled back the schedule pressure on the NET (No Earlier Than) August 28 launch of Atlantis, as she re-starts International Space Station Assembly missions, carrying the P3/P4 truss uphill.
Her sister, Discovery, will be supporting as the LON shuttle, in tandem with preparations for her second mission of the year, STS-116, currently NET December 14.
With Endeavour rejoining flight operations in 2007, NASA hopes to launch five missions next year, with Endeavour's first mission since her long stand-down post Columbia and major modification period being STS-118, carrying S5, Spacehab-SM, ESP3. STS-118 is currently NET June 11, although she will be supporting LON requirements for Atlantis' February 22 STS-117.
2008 is set to be a highlight year for the final flights of the Shuttle, with five fights including the Hubble Space Telescope Servicing Mission, tagged STS-125 - HST-SM04.
The NET April 11, 2008 will be the only flight without the 'safe haven' of the International Space Station, while also being scheduled after the handover of launch pad complex 39B for recommisioning into the test pad - and eventual launch pad - for the CLV (Crew Launch Vehicle).
Evaluations are taking place for the possibility of a unique and ambitious 'single pad rescue mission,' should there be a major problem with Discovery during the servicing of Hubble.
The mission should - if the manifest listings are followed in order - be listed as STS-325, although STS-199 has appeared on some documents relating to STS-125 - which has been confirmed as the fourth and final servicing mission to Hubble.
Da NasaSpaceFlight.com:
NASA ready to roll with Atlantis and STS-115
By Chris Bergin, 7/17/2006 11:29:00 PM
http://www.miomanager.com/Mio_Files/library/1016/sts-115.gif
While NASA celebrates the successful conclusion to STS-121, following Monday's return of Shuttle Discovery, the kick-start to the task of completing the International Space Station (ISS) starts in earnest next month.
Atlantis' STS-115 mission, with a NET (No Earlier Than) August 27 launch date, is a major step up from Discovery's mission, a point emphasised by Shuttle manager Wayne Hale, who classed the mission as "the most complicated assembly mission in the history of human space flight."
As Discovery rolled back into her home Orbiter Processing Facility (OPF 3), sister ship Atlantis is just a week away from leaving her home (OPF 1) to rollover to the VAB (Vehicle Assembly Building) in preparations to be mated with the STS-115 stack.
Atlantis' mission payload will be carrying the Port 3/4 truss - the next major addition to the 11-segment integrated truss structure that will eventually span more than 300 feet. The truss, with its two large solar arrays, is a vital component in supplying extra power to the future configuration of the orbital outpost.
'We are launching in just six weeks time on probably the most complicated assembly mission that has ever been scheduled in human space flight,' said Hale. 'We have the team practised and battle hardened and ready to go do that.'
STS-115, according to its Flight Plan, will involve a 12 day mission, incorporating three spacewalks (EVAs) and the installation of the truss segment - plus deployment of its solar arrays.
'The primary objective of this flight is to deliver and integrate the completion of ISS Stage 12A with the P3/P4 Integrated Truss Segment (ITS). The P4 Photovoltaic (PV) Module (PVM) contains two beta gimbal/PV array assemblies, two Beta Gimbal Transition Structures (BGTSs), one Integrated Equipment Assembly (IEA) ? Type I, and associated cabling,' noted the Flight Plan.
'The cargo element also includes 6 battery sets, PV radiator, 2 Unpressurized Cargo Carrier Attach Systems (UCCAS), Solar Array Rotating Joint (SARJ) and preintegrated Orbiter Space Vision System (OSVS) targets. The CE occupies the majority of the payload bay and is attached in the payload bay by four active longeron trunnion latches and two active keel trunnion latches.
'Also part of the LP are the ISS Utilization payloads, which consist of six unpowered and three powered experiments.'
Hale also noted that a meeting on Friday will finalise the date for when Atlantis will be making the trip over the VAB, whilst confirming launch processing is ahead of schedule.
Much of the gained contingency was earned by Lockheed Martin engineers and technicians, who worked around the clock to changeout the ECO (Engine Cut Off) sensors in ET-118 at KSC, way ahead of schedule. Initially, only one day of contingency (for STS-301 LON - Launch On Need) remained following the arrival of the 'incompleted' tank.
A few more days of work will be carried out on Atlantis, including the changeout of around 100 gap fillers around the ET umbilical doors, resulting from a few issues spotted during Discovery's two week journey in orbit.
'We have (Atlantis) almost ready to rollout - and we have gone back and looked at the little bugs that we saw on Discovery, in terms of gap fillers and thermal blankets. We have also looked very hard at the APU (Auxiliary Power Units) system,' added Hale.
'This Friday we will have our rollout review for Atlantis, and next Monday or Tuesday we will see the rollout (rollover) of Atlantis to mate with the tank and solid rocket boosters.'
Subject to Atlantis' launch will be the status of Discovery, as she is required to support her sister as the rescue vehicle during STS-115. Managers will be able to assess the status of Discovery by the time Atlantis is due to launch, as Discovery will be half way through her turnaround processing for STS-116 - her primary mission, which is set to launch in December.
'We will be working very hard to get Discovery turned around. The landing at the Kennedy Space Center gives us an additional week of time that we would have normally worried about in the processing if we had landed out west (at Edwards Air Force base in California).'
Hale also added that ET-123, the tank which will fly with Discovery on STS-116 (and STS-301 if required) is on schedule, with an arrival time of September 10 - five days before the deadline for LON processing.
'So we're on track for the launch of Atlantis, we will be well covered from a rescue flight standpoint,' Hale noted. 'We also have considerable margin to get Discovery ready for December.'
Should all go to plan, NASA will be able to launch three times before the year is out.
Azz! ma riescono a preparare gia' Discovery per il LON (STS 301) ai primi di settembre? complimenti! :eek:
La missione dell'Atlantis sara' verosimilmente l'ultima delle RTF e con il "backup"?
Intendo, la missione del Discovery prevista per dicembre e quella dell'Endeavour non prevederanno piu' il lancio di un secondo shuttle in caso di necessita'?
(ero rimasto che per l'eventuale missione di manutenzione/riparazione dell'hubble prevedevano questo in quanto l'equipaggio non puo' cercar rifugio nell'ISS in caso di necessita')
Azz! ma riescono a preparare gia' Discovery per il LON (STS 301) ai primi di settembre? complimenti! :eek:
La missione dell'Atlantis sara' verosimilmente l'ultima delle RTF e con il "backup"?
Intendo, la missione del Discovery prevista per dicembre e quella dell'Endeavour non prevederanno piu' il lancio di un secondo shuttle in caso di necessita'?
(ero rimasto che per l'eventuale missione di manutenzione/riparazione dell'hubble prevedevano questo in quanto l'equipaggio non puo' cercar rifugio nell'ISS in caso di necessita')
Beh sono ormai tornati al normale turn-around degli orbiter, e in passato hanno anche fatto 6 lanci all'anno, quindi è tutto nei tempi fattibili.
L'STS-121 era la seconda ed ultima missione RTF, quindi con l'Atlantis si torna alle missioni completamente dedicate, in questo caso alla completamento dell'ISS. Per quanto riguarda il Launch On Need, inizialmente doveva terminare dopo le prime 2 missioni, quindi proprio con l'STS-121, ma è stata prolungata la validità di questo criterio di lancio per altre tre missioni. Avevo già riportato questa notizia pochi giorni fa:
http://www.nasaspaceflight.com/content/?cid=4626
:)
Da Spaceflightnow.com
Space Shuttle Launch Manifest
http://www.spaceflightnow.com/shuttle/sts115/fdf/images/manifest.gif
NasaSpaceFlight.com:
NASA draws up STS-116 troubleshoot
Chris Bergin, 8/17/2006 8:17:00 PM
While NASA prepares for the launch of Shuttle Atlantis on STS-115 at the end of the month, the agency is working on solutions for Discovery's STS-116 mission, which could suffer a stranglehold on its launch window, due to a problem called YERO.
YERO, or Year End Rollover, could prove to be a problem if Discovery launches late in her window, which would see her on orbit during the change of year to 2007 - which has an adverse effect on flight software.
A number of documents acquired by this site show NASA is working on both the potential issues that may arise with the orbiter's reaction to a change of year whilst on orbit - along with a troubleshooting test that will be carried out in October.
'STS-116 launch window may result in Shuttle operations over the year end,' noted the troubleshooting outline document. 'If so, at midnight GMT on Dec. 31 the MTUs (Master Timing Units) will rollover to day 1 and PASS (Primary Avionics System Software) flight software, which increments to day 366, will declare them failed and fault down to internal GPC time.
'The purpose of this test is to verify that the YERO procedure successfully forces STS-116 PASS FSW to accept MTU time and correctly configures it for continued operations, through landing.'
A post-test briefing will be held on October 31, well ahead of STS-116's Flight Readiness Review, which could see Discovery's mission either going ahead as planned - with a solution in place, a restriction of the launch window being reduced to just three days, or the launch window being moved to 2007.
Should a YERO event prove to be unacceptable for flight, the launch window opportunity for Discovery in December will end after December 16, as noted in the YERO outline document: 'Potential YERO event in flight if launch after December 16.'
NASA has no real experience of how an orbiter would react on orbit with a change of year, given what would have been the only previous YERO flight - STS-32 in 1989 - suffered a launch slip.
However, NASA does have an arsenal of testing resources to fall back on, noted as the four SAIL (Shuttle Avionics Integration Lab) tests, completed at the end of 2005, which was recommended for contingency use only.
Processing with Discovery is going smoothly in the flow, allowing NASA a relaxed timeline in completing evaluations for making a decision on projected impacts - allowing engineers and technicians two months to report back with their findings.
The overview document is clear in its current standing on the impact, with the findings to 'Determine which launch dates MOD can support - YERO event while docked: Timeline impacts - Post-undock: No ISS resources (comm, att cntl) - YERO not permitted: Launch window impact.
'If YERO option is permitted - STS-116 Team will: Determine placement of YERO procedure in flight timeline (for portions which can be delayed).'
A full agenda has been tasked on the 'YERO team' - allowing for a clear representation of options available for shuttle managers, which will likely report back to various PRCB meetings at the Johnson Space Center.
'YERO Team will: Determine which YERO steps may be delayed, and for how long. Identify impacts and point-of-contact for affected areas. Develop flight-specific procedure for STS-116 (on-board and ground).
'Support integrated STS-116 SAIL/MCC test in conjunction with FSW verification team(include other centers, where possible). Revisit MCC rollover test (may piggy-back with ISS BCC test). Work with DT to develop flight-specific YERO sims for STS-116 team (on-orbit and entry teams).
The document continues with a variety of potential impacts, how long they could impact the orbiter, and potential on orbit solutions should YERO manifest itself during the mission during the change of year.
The main concerns are loss of General Purpose Computer function and control of the orbiter for a undefined period of time. Such considerations need to be taken into account when the mission time may be extended into a YERO event, for reasons such as being waived off from the planned landing date due to unacceptable weather at the landing facilities.
The full test in October will give a clearer picture on how NASA should proceed.
The other main issue surrounding the launch window for STS-116 - namely the External Tank shipping date for Atlantis' LON (Launch On Need - STS-317) requirement is starting to show signs it will arrive at the Kennedy Space Center within the required timelines.
Memos note that ET-124 is now catching up with the scheduled arrival time to support STS-317's NET 9th of February launch date requirement.
ma non ci credooo.. :doh:
pensavo che problemi del genere li avessero risolti ancora nel 1999 per lo spauracchio del Y2K bug!
in piu' pensavo che alla Nasa fossero piu' lungimiranti dei comuni programmatori e avessero previsto da sempre una simile eventualita'!!
vabbe' dai, hanno quattro mesi di tempo per approntare un bugfix.
è un pò più complicato... non è un problema stile y2k. In questo caso i GPC (General Purpose Computers) sono in grado di rinoscere il cambio di data, il problema è che il PASS potrebbe non riconoscere correttamente la data re-impostata dagli MTUs.
Questa condizione è dovuta ad una classica procedura NASA... l'unica volta in cui una missione ha rischiato continuare durante il rollover, semplicemente è stata posticipata. Le restrizioni dopo-Columbia non permettono più di sottovalutare possibili problemi del genere, soprattutto se, in caso di necessita di utilizzare la ISS come "safe-haven" e quindi in previsioni di una lunga permanenza in orbita, ci sia come in questo caso la possibilità di un rollover durante la missione.
d'accordo, ma dal momento che il problema e' noto da tempo perche' non si sono messi subito a lavorarci sopra? (per esempio durante i due anni di fermo degli shuttles dopo l'incidente del Columbia).
Le risorse tecniche mi pare non manchino:
However, NASA does have an arsenal of testing resources to fall back on, noted as the four SAIL (Shuttle Avionics Integration Lab) tests, completed at the end of 2005, which was recommended for contingency use only.
Alla peggio potrebbero sempre simulare il cambio dell'anno sull'Endaevour.. :rolleyes:
Si è vero octane... è come il problema (già risolto) dei due bulloni troppo corti che tengono ancorata l'antenna Ku-band dell'Atlantis. Erano già stati sostituiti sugli altri due orbiter ma non sul Columbia e l'Atlantis.
Detto questo, non si può testare sull'Endevour, occorre simulare una missione, cosa non possibile con un orbiter vero, ma solo con un simulatore, cosa che verrà fatta.
Cmq son le solite politiche NASA ante-Columbia.
Ok, sterili polemiche a parte (le mie), riusciranno a sistemare in tempo il software di bordo "PASS" senza dover anticipare o posticipare la missione?
molto probabilmente i test daranni risultati positivi e non ci sarà nemmeno il bisogno di intervenire.
ciao a tutti, volevo chiedervi se avete o sapete dove trovare qualche immagine dello shuttle mentre entra nell'atmosfera terrestre.
Grazie in anticipo
ciao a tutti, volevo chiedervi se avete o sapete dove trovare qualche immagine dello shuttle mentre entra nell'atmosfera terrestre.
Grazie in anticipo
Ciao,
puoi provare a cercare nella biblioteca digitale del Kennedy Space Center
http://mediaarchive.ksc.nasa.gov/search.cfm
anche se non credo si possa trovare molto su questa fase della missione; le foto dovrebbero essere infatti scattate da un satellite nelle vicinanze o dalla Stazione Spaziale Internazionale. I questo caso pero' si vedrebbe al piu' l'ingresso negli strati piu' alti e piu' rarefatti dell'atmosfera terrestre.
avevo già guardato ma non ho trovato niente...il fatto è che l'avevo vista in un poster e pensavo di poter rirovarla in internet
Da NASASpaceFlight.com (http://www.nasaspaceflight.com/content/?cid=4816):
STS-125 - NASA's Flight Of Opportunity
Chris Bergin, 9/18/2006 5:55:00 PM
Flagship mission STS-125, better known as the final Hubble Space Telescope Servicing Mission, has officially entered NASA's flight manifests as the "Flight Of Opportunity."
HST SM-04 is currently scheduled for No Earlier Than (NET) April 17, 2008, involving Shuttle Discovery. Confirmation of the mission is expected next month.
While moves are being made to attempt to bump the launch up to the end of 2007, initial preparations continue towards the dual approach of training a veteran crew to carrying out the servicing of the space telescope, along with evaluations for a one-of-its-kind LON (Launch On Need) rescue mission being on standby.
The last Hubble Space Telescope servicing mission took place on STS-109, with one of the most spectacular launches ever witnessed at the Kennedy Space Center, as Columbia's dawn launch pierced through low clouds, lighting up the State of Florida in the process
December 2007 is ambitious to say the least, due to natural slippage in the launch manifest. Both STS-116 and STS-117 are under threat of slipping a few months due to delays with Atlantis' External Tank (required both for Atlantis' primary mission and her support of Discovery's December mission).
Realistically, the Hubble mission is expected to remain sandwiched between the two major launch and installation missions for the Japanese Space Agency (JAXA) in early 2008, currently dated - before slippage - as NET December 6, 2007, STS-123/1J/A, Endeavour - JEM ELM-PS, SLP-D1 with SPDM Dextre, and NET February 7, 2008, STS-124/1J, Atlantis - JEM PM, JEM RMS.
The latest manifests, dated September 12 and 13, now include payloads for all of the remaining flights in the Shuttle manifest. Previously, manifests had only shown scheduled payloads up to Node 2/STS-120.
LON missions only - at present - extend as far as STS-322, which is in support of STS-120. Installing a rescue requirement for the Hubble Servicing Mission would prove to be extremely complex.
It is hoped that continued confidence in on-orbit inspection, repair techniques and improved External Tanks that suffer less foam liberation will mitigate the need to have an orbiter on standby for Discovery's mission, which was intimated by Shuttle manager John Shannon during a recent press conference.
'The question on Hubble is Launch On Need, because that's going to be extremely difficult to do,' he noted, pointing out the rush to launch another orbiter, while Discovery is used as a lifeboat. 'It's going to be very tough.'
However, breaking source news tonight notes that Constellation may not see the handover of Pad 39B on the schedule date of March 31, 2007, due to 'evaluations of having two pads available for a 2007 Hubble servicing mission, plus LON requirement.'
Pad 39B is set to undergo construction (and dismantling) work next year, ahead of the Ares I-1 test flight. An article will follow when further information is available.
Meanwhile, a recent incident involving one of the new cameras that will fly with Discovery to upgrade an existing part of the telescope will not affect the scheduling of the mission, sources note.
Below is the current STS launch manifest (updated).
01 - December 14, 2006 - STS-116 - 12A.1 - Discovery - P5, Spacehab-SM, ICC
[February 9, 2007 - STS-317 - LON for STS-116 - Atlantis]
02 - February 22, 2007 - STS-117 - 13A - Atlantis - S3/S4
[May 8, 2007 - STS-318 - LON for STS-117 - Endeavour]
03 - June 11, 2007 - STS-118 - 13A.1 - Endeavour - S5, Spacehab-SM, ESP3
[July 26, 2007 - STS-320 - LON for STS-118 - Atlantis]
04 - August 9, 2007 - STS-120 - 10A - Atlantis - Node 2, PDGF
[September 28, 2007 - STS-322 - LON for STS-120 - Discovery]
05 - October 17, 2007 - STS-122 - 1E - Discovery - Columbus, MPESS
06 - December 6, 2007 - STS-123 - 1J/A - Endeavour - JEM ELM-PS, SLP-D1 with SPDM Dextre
07 - February 7, 2008 - STS-124 - 1J - Atlantis - JEM PM with JEM RMS
08 - April 17, 2008 - STS-125 - HST SM-04 - Flight Of Opportunity - Discovery
09 - June 19, 2008 - STS-119 - 15A - Endeavour - S6
10 - August 21, 2008 - STS-126 - ULF2 - Atlantis - MPLM, LMC
11 - October 30, 2008 - STS-127 - 2J/A - Discovery - JEM EF, ELM-ES, SLP-D2
12 - January 22, 2009 - STS-128 - 17A - Endeavour - MPLM, LMC
13 - April 30, 2009 - STS-129 - ULF3 - Discovery - ELC1, ELC2
14 - July 16, 2009 - STS-130 - 19A - Endeavour - MPLM, LMC
[October 22, 2009 - STS-131 - ULF4/CLF - Discovery - ELC3, ELC4]
15 - January 21, 2010 - STS-132 ? 20A - Endeavour - Node 3 with Cupola
[July 15, 2010 - STS-133 - ULF5/CLF - Endeavour - ELC5, ELC1]
Da SpaceFlightNow.com (http://www.spaceflightnow.com/shuttle/sts116/061006nighttime):
Shuttles to resume nighttime launches; Atlantis damaged
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: October 6, 2006
NASA managers met Thursday and agreed to relax a self-imposed post-Columbia daylight launch constraint, clearing the way for the shuttle Discovery's liftoff Dec. 7, around 9:38 p.m. EST, on a complex space station assembly mission. It will be the first night shuttle launch since 2002.
But agency managers attending a program requirements change board meeting reserved the option of requiring daylight launches for flights with external fuel tanks featuring significant design changes.
One such proposed change is a modification of the tank's so-called ice-frost ramps, aerodynamically shaped foam insulation used to prevent pre-launch ice buildups on fittings that support external pressurization lines and a cable tray.
NASA and contractor engineers have been working on a redesign to reduce the amount of foam used to make the ice-frost ramps and thus minimize the possibility of debris shedding during ascent. But the ramps performed well during the past two missions and some engineers now favor leaving the design alone.
Another meeting to discuss the topic is planned for early November.
The ice-frost ramps are made up of foam poured into molds and then shaped by hand. Because the ramps are built up on top of already existing foam, engineers believed they were susceptible to temperature-induced cracks that could lead to in-flight debris shedding.
The ramps were officially classified as "probable-catastrophic" prior to the last two shuttle missions. That means if no changes were made, one could expect a 50-50 chance of a catastrophic failure over the 100-flight design life of a space shuttle.
Before mission STS-121 last July, NASA Administrator Mike Griffin said he did not agree with the probable-catastrophic designation and Discovery was cleared for flight as is. Likewise, Atlantis was cleared for launch last month on mission STS-115 with the understanding that a new ice-frost ramp design would be implemented as soon as possible.
As it turned out, no significant ice-frost ramp damage or foam shedding was seen during the last two flights. An ongoing engineering analysis, based in part on in-flight video of the tank, indicates what foam does separate in flight comes off after the tank is out of the dangerous lower regions of the atmosphere.
Going into Discovery's flight last July, the odds of a catastrophic IFR failure were believed to be between 1-in-75 and 1-in-100. The odds currently are believed to be in the neighborhood of 1-in-575 or better, according to a senior manager familiar with the ongoing analysis. As such, the ramps likely will not be classified as probable-catastrophic for Discovery's upcoming flight in December.
At the Kennedy Space Center, meanwhile, engineers are assessing options for fixing a radiator panel mounted on the inside of the shuttle Atlantis' right-side payload bay door. The panel apparently was damaged when a piece of space debris or a micrometeoroid slammed into the radiator, presumably during the shuttle's flight last month, blasting .108-inch-wide hole in the upper surface and destroying the aluminum honeycomb material below before exiting the other side.
The impact did not threaten the crew and the damage can be repaired. But it illustrates the danger posed by micrometeoroid/orbital debris (MMOD) and the reason why NASA considers such strikes a high risk. The odds of a catastrophic impact-related entry failure range between 1-in-210 to 1-in-350, depending on whether the astronauts inspect the ship in orbit prior to re-entry.
At orbital velocities, even tiny pieces of debris pose a serious threat. An aluminum sphere just .4 inches across moving at 10 kilometers per second, or 22,370 mph, carries the same impact energy as a bowling ball moving at 300 mph.
A preliminary engineering analysis shows the impact in question was one of the most significant instances of MMOD damage in shuttle history, second only to a cargo bay door impact during shuttle mission STS-72 in 1996.
The shuttle's 60-foot-long payload bay doors each feature four radiator panels that are exposed to space once the doors are opened in orbit. The forward two radiator panels measure about one inch thick, feature Freon coolant tubes positioned about 1.9 inches apart and can pivot to radiate from both sides. The aft panels are fixed and only radiate from one side. They measure a half inch thick and feature coolant tubes separated by about 5 inches. The interior of the panels is made up of an aluminum honeycomb material.
The impact on Atlantis's right-side, or starboard, radiator was found roughly midway between two coolant lines on panel No. 4. The object blasted a .108-inch-wide hole and presumably broke apart on impact. The resulting spray of debris created a cone-shaped damage cavity immediately below the face plate, destroying the honeycomb interior to the full half-inch depth of the panel. The lower face sheet was pushed out in two places. A .26-inch crack and a .03-inch-wide exit hole were found.
As part of NASA's post-Columbia safety protocols, the shuttle and space station fly in an orientation that protects the shuttle's critical wing leading edge panels from direct, worst-case impacts in the line of flight. In addition, the astronauts now carry out detailed inspections of the shuttle's heat shield after reaching orbit and again before re-entry to make sure no MMOD impacts occurred during the course of the mission.
Areas of the shuttle that are not critical for re-entry are not inspected and the damage to Atlantis's radiator panel No. 4 was not discovered until post-flight servicing at the Kennedy Space Center.
A senior NASA manager said the impact damage was unlikely to prompt a change in the shuttle's orbital orientation. He said program managers understand the radiator panels and cockpit windows face a higher risk of impact damage because of the shuttle's orientation. But he said the risks associated with wing leading edge impacts are more severe.
The shuttle has two Freon coolant loops and while the loss of one would force a crew to return to Earth at the next available U.S. landing site, computer software is in place to immediately isolate a leak even if the event occurred when the crew was asleep or otherwise occupied. Assuming a leak was quickly isolated, the astronauts could implement contingency procedures and press ahead with a near-normal mission despite the damage to one radiator panel.
As for an impact on the shuttle's cockpit windows, engineers do not yet know if the debris in question would have penetrated the thick multi-pane glass. The three panes making up the six forward cockpit windows have a combined thickness of 2.55 inches. The three panes making up each overhead window have a combined thickness of 1.58 inches.
Some 11,000 objects 3.9 inches in diameter or greater are currently tracked by Air Force radars and optical systems. About 100,000 objects are believed to be present that are between .39 inches across and 3.9 inches in diameter. Most of those are not tracked and pose a threat to spacecraft in low-Earth orbit and to communications and weather satellites in higher orbits.
La Discovery e' nel VAB in preparazione per la missione STS-116.
http://www.spaceflightnow.com/shuttle/sts116/061030preview/
http://www.nasaspaceflight.com/content/cat.asp?cid=4
attendiamo fiduciosi GioFX per l'apertura di un thread dedicato :D
La Discovery e' nel VAB in preparazione per la missione STS-116.
http://www.spaceflightnow.com/shuttle/sts116/061030preview/
http://www.nasaspaceflight.com/content/cat.asp?cid=4
attendiamo fiduciosi GioFX per l'apertura di un thread dedicato :D
Arrivo! :D
PS: è maschile! il Discovery! :O
:sofico:
Arrivo! :D
PS: è maschile! il Discovery! :O
:sofico:
Ho usato il femminile perche' tutti i siti anglofoni usano cosi'.. :rolleyes:
(si riferiscono anche con "She" :D )
Concordo comunque che "attributi maschili" siano piu' appropriati! ;)
Ho usato il femminile perche' tutti i siti anglofoni usano cosi'.. :rolleyes:
(si riferiscono anche con "She" :D )
Concordo comunque che "attributi maschili" siano piu' appropriati! ;)
Ma infatti in italiano... :p
Si sa che gli ammeriggani chiamano tutte la "navi" she... :D
NasaSpaceFlight.com:
http://www.nasaspaceflight.com/content/?cid=4987
Atlantis gains Hubble servicing swansong
By Chris Bergin, 1/8/2007 10:49:00 PM
Shuttle Atlantis has been handed a flagship finale, following the confirmation that she will now be the orbiter that will now conduct the Hubble Space Telescope servicing mission, with the launch date slipping to September 11, 2008.
The decision to swap STS-125 - known as HSM-04 - from Discovery to Atlantis was confirmed by the January 8 launch schedule document, which sees a widescale change to the shuttle mission manifest.
Moving to Atlantis was suggested around the time the confirmation of the servicing flight was given by NASA administrator Mike Griffin back in October.
Initially called the Flight of Opportunity, NASA had continued to place STS-125 as part of Discovery's launch schedule. However, evaluations on swapping with Atlantis surrounding adding another flight to her final schedule, prior to 2008 retirement, had been bubbling under the surface of NASA's plans.
Now NASA have decided to switch STS-125 with one of Atlantis' scheduled missions, STS-126. The rationale on this move has not yet been explained, although the upcoming PRCB (Program Requirements Control Board) meeting - the first of the new year - may shed some light on the decision.
With STS-126's switch, Discovery also becomes the rescue orbiter on LON-326 (Launch On Need), with a NET launch date requirement just one week after Atlantis is due to launch to Hubble.
This means Discovery will be sat on Launch Pad 39B at the time of Atlantis' launch from 39A. While that wouldn't be the first time two orbiters were out of adjacent pads, ironically it will be 39B's final shuttle act, prior to being handed over to Constellation immedialty after the rescue contingency is stood down.
This, the fifth mission to Hubble, will also be the Atlantis' first - and last - visit to the space telescope, after Hubble was launched by Discovery. Previous HSMs have been carried out by Endeavour, December 1993, Discovery, February 1997, Discovery, December 1999 and Columbia, March 2002.
STS-125 - which will be commanded by Scott Altman - will be the highlight mission prior to the 2010 retirement of the fleet, with the mission to Hubble widely lobbied by the science community since Griffin intimated that he would reverse the previous cancellation by former administrator Shaun O'Keefe - if he was satisfied the safety of the crew was within strict requirements.
O'Keefe's decision was understood at the time - if not criticized for being made by a still grieving agency post STS-107 - given the lack of a proven on-orbit repair capability.
However, following the post return to flight successes in both reducing foam liberation, and a refined rescue mission contingency, Griffin was satisfied that the mission to Hubble was safe enough to fly.
At the time of the decision it was confirmed that a unique rescue requirement would be placed in support of the servicing, given the lack of the International Space Station (ISS) Safe Haven option. If it was required, Discovery would launch to the stricken Atlantis, for a series of EVAs that would transfer the crew of Atlantis on to Discovery for a return home.
For the mission, Atlantis will carry 22,000 pounds of hardware to the aging telescope, with four spacewalks (EVAs) required during the 11 day mission. One of the highlights of the mission will be an EVA that will replace an electronics board inside the Hubble's Space Telescope Imaging Spectrograph (STIS), which requires 111 screws being removed in the space of 45 minutes.
STS-121 astronaut and EVA specialist Piers Sellars, speaking to the BBC's Sky at Night this week noted that the crew are already undergoing rigorous training in preparation for the mission.
In the payload bay will be primary elements SLIC (Super Lightweight Interchangeable Carrier), ORUC (Orbital Replacement Unit Carrier), FSS Flight Support System (Structure) and MULE (Multi-use Logistic Equipment Carrier) - that latter two elements swapping places since the previous mission to service Hubble.
Other moves noted in the brand new manifest include the next mission, STS-117, being evaluated for a one day advance of the current NET (No Earlier Than) launch date of March 16, STS-119 is being delayed from June 19 to July 7, and the post Hubble orbiter change seeing a number of missions switching between Discovery and Endeavour), with additional launch dates changes on those missions.
Cominciano a uscire un po' di info interessanti sulla missione dell'Atlantis STS-117.
L'orbiter dovrebbe entrare nel VAB oggi per l'aggancio con l'external tank e i boosters.
da NasaSpaceFlight.com:
http://www.nasaspaceflight.com/content/?cid=5011
http://content.nasaspaceflight.com/library/1016/AtlantisR.JPG
At present, Atlantis is heading towards an early morning rollover on February 7 for the short trip to the Vehicle Assembly Building (VAB).
Once inside the giant building, Atlantis will be mated with ET-124 and the twin Solid Rocket Boosters. Rollout to launch pad 39A is expected one week later.[...]
@GioFX
attendiamo che tu apra un thread apposito ;)
si si, lo apro sabato se riesco! Grazie per gli update! :)
lzeppelin
10-02-2007, 18:26
iscritto!
Cambiamento radicale nel manifest!
Da NasaSpaceFlight.com:
Seven missions slip - Hubble moves up, begins major planning
By Chris Bergin, 3/27/2007 11:12:02 PM
STS-125 - the final Hubble serving mission - has unexpectedly moved up NASA's shuttle schedule, in the biggest schedule shake-up in years, involving seven missions slipping and the swapping of orbiters on three missions.
The move of STS-125 to earlier next summer - and now only seven missions away - was also accompanied by the opening salvo of major planning documentation for the flagship mission, which remains as Atlantis' swansong.
The changes to the manifest are - as always - part of an ongoing process, with the alterations in this instance being used to ensure the possibility of four flights in 2007.
As revealed by this site on Monday, three missions are swapping orbiters, STS-120 - to Discovery, STS-122 - to Atlantis, and STS-124 - to Discovery. However, the now-documented changes are more wide-ranging than previously expected.
With the second week in April being decisive for STS-117's launch date decision, currently - should full repairs on ET-124 prove to be viable - Atlantis is set to kick off 2007 with a NET (No Earlier Than) launch date of May 11. NET June 17 is the other option, should NASA decide to swap tanks with the soon-to-arrive ET-117.
'NASA is evaluating potential manifest options to address the STS-117 launch delay caused by hail damage to Atlantis' external fuel tank, designated ET-124,' noted a White Paper from NASA on the Change Request on Shuttle Manifest.
'To facilitate this evaluation, a manifest Change Request (CR) was entered into the Space Shuttle program configuration management system on March 26, 2007. The CR reflects several key assumptions that are needed for the teams to evaluate the manifest.
'It first proposes a May 11 planning date for the STS-117 launch. Although the program may not make that date, it requires some mark on the calendar from which to make its evaluations.
'The CR also proposes switching Shuttles for certain missions to maximize the availability of orbiters while minimizing in the near term the impact on mission accomplishment. All of these proposed changes likely will change again before these missions are actually launched.
'Although the CR does not propose a launch schedule after October 2008, the program maintains its commitment to accomplish our mission and end Shuttle operations by the end of September 2010.
Looking through these manifest changes in the schedule, Endeavour rejoins flight operations with STS-118, 16 days later than previously scheduled, with a NET launch date of July 14. Other slips range from one to two months in length.
Those changes become more complex in the late 2007 and 2008 schedule, involving the move of STS-120 from Atlantis to Discovery, with a launch planning date of October 13, 2007. Moving STS-122 from Discovery to Atlantis, with a launch planning date of December 6, 2007. STS-123 launch planning date of February 14, 2008.
STS-124 moves from Atlantis to Discovery, with a launch planning date of April 24, 2008. Accelerating STS-125, the Hubble Servicing Mission, into late August 2008. STS-119 launch planning date into October 2008, but more importantly, proposes to use STS-119/Endeavour as the launch on need rescue (LON) vehicle for STS-125 - and will be sat on Pad 39B when Atlantis launches on STS-125.
STS-125 in turn has gained a large upturn in planning this month, with over 22 documents now added to its baseline. These planning documents range from mission control support to on-orbit activities - such as timelines and EVAs. Documents show refinements to the mission, laying the foundations for what will be a full flight plan being produced in the coming months. (Another article will follow on the Hubble planning documents.)
However, STS-125 is still a long way off from flying, with six other missions preceding it, and the immediate focus being placed on STS-117.
'This is a working level process that involves evaluating options, for planning purposes only, in order to identify opportunities to minimize impacts to the overall program schedule,' added the White Paper on the manifest changes, which were signed with a recommendation to approve. 'To assist in the evaluation, a number of assumptions have been made that are intended to provide a common framework from which the teams will evaluate the viability of the proposed changes to the manifest.
'It must be emphasized that repair work and engineering analysis continue, and it will not be practical to make a decision on ET-124 utilization and the associated change in the STS-117 launch date before the April 10, 2007 progress review.
'Much of the early information used in the working group manifest evaluation process is based on standard templates for mission preparedness and do not necessarily reflect specific information on the condition of the vehicle and the progress of repair. It is simply too early to know the specific STS-117 launch date at this point. The STS-117 launch date will impact other manifest dates, at least in the near-term.
'As such, the evaluation process and any specific information currently being considered are subject to change as more information becomes available. Any formalized change in the baseline manifest will undergo a standard Shuttle program review that will include appropriate interfaces with other NASA organizations.'
Below is an updated launch schedule, based on the March 27th documentation:
2007
April 7 - Soyuz TMA-10 (14S)
May 11 (TBD) - STS-117 (13A) - Atlantis - S3/S4
May 12 (TBD) - Progress M-60 (25P) (depends on STS-117 flight)
[July 5 (TBD) - STS-318 (Rescue STS-117) - Endeavour]
July 14 (TBD) - STS-118 (13A.1) - Endeavour - S5, Spacehab-SM, ESP3
August 16 - Progress M-61 (26P)
[September 28 (TBD) - STS-322 (Rescue STS-118) - Discovery]
October 2 - Soyuz TMA-11 (15S)
October 13 (TBD) - STS-120 (10A) - Discovery - Node 2 'Harmony'
November (TBD) - ATV-1 'Jules Verne'
[December 2 (TBD) - STS-320 (Rescue STS-120) - Atlantis]
December 6 (TBD) - STS-122 (1E) - Atlantis - Columbus, ICC-Lite
December 12 (TBD) - Progress M-62 (27P) (depends on STS-122 flight)
2008
[January 31 (TBD) - STS-323 (Rescue STS-122) - Endeavour]
February 12 (TBD) - Progress M-63 (28P) (depends on STS-123 flight)
February 14 (TBD) - STS-123 (1J/A) - Endeavour - JEM ELM-PS, SLP-D1 with SPDM 'Dextre'
April 8 - Soyuz TMA-12 (16S)
[April 10 (TBD) - STS-324 (Rescue STS-123) - Discovery]
April 24 (TBD) - STS-124 (1J) - Discovery - JEM PM with JEM RMS
[July 23 (TBD) - STS-319 (Rescue STS-124) - Endeavour]
August 28 (TBD) - STS-125 (HST-SM4) - Atlantis
[September 4 (TBD) - STS-3XX (Rescue STS-125) - Discovery]
October (TBD) - STS-119 (15A) - Endeavour - S6
2009
TBD - STS-126 (ULF2) - Discovery - MPLM, LMC
TBD - STS-127 (2J/A) - Endeavour - JEM EF, ELM-ES, SLP-D2
July - HTV-1
TBD - STS-128 (17A) - Discovery - MPLM, LMC
TBD - STS-129 (ULF3) - Endeavour - ELC1, ELC2
TBD - MLM (3R) - ERA
2010
TBD - STS-130 (19A) - Discovery - MPLM, LMC
[TBD - STS-131 (ULF4/CLF) - Endeavour - ELC3, ELC4]
TBD - STS-132 (20A) - Discovery - Node 3 with Cupola
[TBD - STS-133 (ULF5/CLF) - Endeavour - ELC5, ELC1 (TBD)]
http://www.nasaspaceflight.com/content/?cid=5058
Da NASASpaceFlight.com:
http://www.nasaspaceflight.com/content/?cid=5146
Atlantis avoids early retirement - will keep flying to 2010
By Chris Bergin, 6/23/2007 11:25:28 PM
NASA managers have decided to manifest shuttle orbiter Atlantis with missions through to 2010, cancelling her previously planned retirement in 2008.
Information gained from STS-122 - the next flight of Atlantis - processing documentation, along with the latest FAWG (Flight Assignment Working Group) manifests, confirm the addition of two further missions for the orbiter, to follow after STS-122 and her flagship STS-125 mission to service the Hubble Space Telescope.
By Chris Bergin, 6/23/2007 11:25:28 PM
NASA managers have decided to manifest shuttle orbiter Atlantis with missions through to 2010, cancelling her previously planned retirement in 2008.
Information gained from STS-122 - the next flight of Atlantis - processing documentation, along with the latest FAWG (Flight Assignment Working Group) manifests, confirm the addition of two further missions for the orbiter, to follow after STS-122 and her flagship STS-125 mission to service the Hubble Space Telescope.
The other mission Atlantis is likely to take is STS-131 (ULF4), carrying the CBC, Russian Docking Cargo Module, manifested to fly NET January 28, 2010.
With this extension to Atlantis' operational lifetime, certain elements of the OMDP can still be safely carried out during pre/post-launch processing intervals.
The ability to keep the fleet flying without the stand-down of OMDP before 2010 was outlined in an October 2006 presentation to the PRCB (Program Control Requirements Board).
Titled the '3 year / 8 Flight OMRSD (Operations Maintenance Requirements Specifications Document) Review,' the presentation from the Orbiter Project Office (OPO) showed that only Endeavour had the ability to keep flying until 2010 before an OMDP was due - under the then current guidelines.
'Current 3 year/8 flight OMDP interval requirement does not support remaining flight manifest without test reset or interval increase,' the presentation opened, before noting that Discovery is actually due an OMDP in March 2008, Atlantis in July 2008, along with Endeavour in July 2010 at the time of the document's creation.
The purpose of the evaluations noted in the presentation was to look at the possibility of extending the OMDP interval requirement to 5.5 years, which would enable the whole fleet to keep flying until the scheduled retirement of the shuttle program.
This appeared favorable, as the review found that out of the '722 subsystem-coded requirements' only 29 'dispositions' were deemed unacceptable past the three year interval - with those requirements likely to be worked on the orbiters during pre/post flight processing flows, compared with 693 'dispositions' classed as acceptable for the extension to a 5.5 year interval between OMDPs.
Concluding that the program will 'define new OMDP new interval of 8 flights and 5.5 years, for extendable requirements,' the shuttle program will 'continue to partner with KSC the Implementation Plans for the items that must be performed prior to 3 years,' with Discovery and her previously due date for OMDP - which ensures that 'based on these OMRSD Reviews, (OMDP, Interval and Time/Cycle), there should be no large impacts to the current manifest.'
Ultimately, this was implemented into the STS-122 baseline, before finally being confirmed with the extension to Atlantis' operation lifetime in the latest FAWG manifests, which also confirm some refinements to the schedule, including the advancement of Endeavour's upcoming return to flight action after a five year wait. Another set of minor refinements were made to the manifest last Friday.
STS-118 now has a new NET date of August 7, assisted by a very smooth processing flow which is allowing the youngest orbiter to rollover out of OPF 2 on July 2, ahead of mating with ET-117 and the twin Solid Rocket Boosters inside the VAB.
Meanwhile, Atlantis - currently at Edwards Air Force Base after Friday's return to Earth on STS-117 - is undergoing a level of post flight processing, including the flushing of residual propellants from her main engines, and the SCAPE operations to remove hazardous hypergolic fuels from her Reaction Control Systems.
After this process, a tail cone faring will be mated on her aft, before being mated with NASA's SCA (Shuttle Carrier Aircraft) next week for the piggyback ride back to KSC.
Her crew, including former ISS crewmember Suni Williams, have arrived back at their home base in Houston on Saturday.
Latest Manifest
2007
July 22 - Progress M-61 (26P)
August 7 - STS-118 (13A.1) - Endeavour - Spacehab-SM, S5, ESP3
[October 5 - STS-322 (Rescue STS-118) - Discovery]
October 10 - Soyuz TMA-11 (15S)
October 20 - STS-120 (10A) - Discovery - Node 2 'Harmony'
[December 2 - STS-320 (Rescue STS-120) - Atlantis]
December 6 - STS-122 (1E) - Atlantis - ICC-Lite, Columbus
December 12 (TBD) - Progress M-62 (27P)
2008
January - ATV-1 'Jules Verne'
[January 31 - STS-323 (Rescue STS-122) - Endeavour]
February 12 (TBD) - Progress M-63 (28P)
February 14 - STS-123 (1J/A) - Endeavour - SLP-D1 with SPDM 'Dextre', JEM ELM-PS
April 8 - Soyuz TMA-12 (16S)
[April 10 - STS-324 (Rescue STS-123) - Discovery]
April 24 - STS-124 (1J) - Discovery - JEM PM with JEM RMS
[July 23 - STS-326 (Rescue STS-124) - Endeavour]
September 10 - STS-125 (HST-SM4) - Atlantis
[September 17 - STS-400 (Rescue STS-125) - Endeavour]
October 16 - STS-126 (ULF2) - Endeavour - MPLM, LMC
2009
January 15 - TBD - Discovery - TBD
April 23 - TBD - Endeavour - TBD
June 30 - TBD - Atlantis - TBD
September 11 - TBD - Discovery - TBD
November 19 - TBD - Endeavour - TBD
2010
January 28 - TBD - Atlantis - TBD
April 7 - TBD - Discovery - TBD
June 10 - TBD - Endeavour - TBD
com'e' che le Rescue missions per gli Shuttle sono con oltre un mese di ritardo rispetto alla missione per la quale devono fornire il supporto?:wtf:
L'equipaggio dello shuttle dovrebbe quindi stare per quasi due mesi nell'ISS? (sai che affollamento! :) )
com'e' che le Rescue missions per gli Shuttle sono con oltre un mese di ritardo rispetto alla missione per la quale devono fornire il supporto?:wtf:
L'equipaggio dello shuttle dovrebbe quindi stare per quasi due mesi nell'ISS? (sai che affollamento! :) )
E' il tempo per il quale è in stand-off il secondo orbiter utilizzato per il soccorso, considerato il tempo per per processare lo stack (integrazione, roll-out, ecc.) e per ri-cicliare il Pad attualmente utilizzato (A) per il lancio.
Per le misisoni della ISS il tempo non è un grosso problema, discorso diverso nel caso della SM4 dell'Hubble, che necessiterà di due orbiter in contemporanea sui due Pad. Al termine della missione il Pad B verrà ufficialmente decommossionato per il programma STS e ceduto formalmente (hand-over) al programma Constellation...
E' il tempo per il quale è in stand-off il secondo orbiter utilizzato per il soccorso, considerato il tempo per per processare lo stack (integrazione, roll-out, ecc.) e per ri-cicliare il Pad attualmente utilizzato (A) per il lancio.
Per le misisoni della ISS il tempo non è un grosso problema, discorso diverso nel caso della SM4 dell'Hubble, che necessiterà di due orbiter in contemporanea sui due Pad. Al termine della missione il Pad B verrà ufficialmente decommossionato per il programma STS e ceduto formalmente (hand-over) al programma Constellation...
capito..
pensandoci poi l'equipaggio avrebbe comunque a disposizione lo spazio abitabile dell'Orbiter (sempre che riescano ad alimentarlo dalla ISS).
A proposito e' stato poi installato il sistema per il rientro autonomo (senza equipaggio) per lo shuttle? Ero rimasto che l'unica operazione manuale era l'apertura dei carrelli, il resto erano ovviamente aggiunte al software di volo.
cominciamo ad entrare nel vivo della missione STS-118..Gio attendiamo te per il thread dedicato! ;)
http://www.spaceflightnow.com/shuttle/sts118/images/sts118sidebar.gif
Endeavour moves to assembly building
In preparation for its first spaceflight in nearly five years, space shuttle Endeavour was transported from its hangar to the Vehicle Assembly Building at Kennedy Space Center on the morning of July 2.
The shuttle will be attached to its fuel tank and booster rockets inside the 52-story VAB. Rollout to pad 39A is scheduled for next week.
Endeavour is targeted for launch to the space station August 7 at about 7 p.m. EDT.
Photo credit: NASA-KSC
http://www-pao.ksc.nasa.gov/kscpao/images//medium/07pd1704-m.jpg
capito..
pensandoci poi l'equipaggio avrebbe comunque a disposizione lo spazio abitabile dell'Orbiter (sempre che riescano ad alimentarlo dalla ISS).
A proposito e' stato poi installato il sistema per il rientro autonomo (senza equipaggio) per lo shuttle? Ero rimasto che l'unica operazione manuale era l'apertura dei carrelli, il resto erano ovviamente aggiunte al software di volo.
Sia per l'alimentazione che per il rientro automatizzato sono stati fatti gli upgrade sull'Endeavour, a seguire il Discovery, per Atlantis che è il primo che verrà ritirato non sono aggiornato se è in programma l'upgrade, ma dubito fortemente.
Il sistema di alimentazione consente l'interscambio di energia elettrica tra la stazione e l'orbiter, ed dovrà essere convalidato dalle prossime missioni dell'Endeavour.
Per quanto riguarda invece il rientro in modo totalmente automatico si è trattato solo di un upgrade software al programma di rientro (per gestire, tra le altre cose, anche il dispiegamento del carrello). Per il resto lo shuttle è già predisposto (da alcuni anni) ad un ipotetico rientro automatico.
Da SpaceFlightNow.com:
http://www.spaceflightnow.com/shuttle/sts117/070703ferry
Atlantis arrives back home after cross-country trip
BY JUSTIN RAY
SPACEFLIGHT NOW
Posted: July 3, 2007
Space shuttle Atlantis returned home to the Kennedy Space Center this morning, completing a two-day coast-to-coast piggyback ride atop a modified 747 ferrying jet that included rare stops in America's heartland.
http://www.spaceflightnow.com/shuttle/sts117/070703ferry/ferryflight.jpg
The Shuttle Carrier Aircraft nears the Kennedy Space Center runway with Atlantis aboard. Credit: Ben Cooper/Spaceflight Now
The shuttle's recent space station construction mission landed at Edwards Air Force Base in California on June 22 after menacing weather precluded a Florida homecoming. Technicians spent a week safing onboard systems and readying the vehicle for the cross-country trip. Once an aerodynamic tailcone was installed, the 100-ton spaceplane was lifted on top of the aircraft and bolted in place.
Atlantis departed the the Mojave Desert base at 9:04 a.m. EDT Sunday. The unique shuttle and 747 duo flew east to the Texas Panhandle, landing in Amarillo shortly before noon EDT for a two-hour refueling stop. The ferry flight completed a 100-minute northeastward leg to Offutt Air Force Base in the afternoon, arriving about 3:45 p.m. EDT for an overnight stay at the military installation on the eastern border of Nebraska.
The voyage continued to Kentucky's Fort Campbell on Monday, arriving at 10:35 a.m. EDT. But unstable weather in the U.S. Southeast halted any further advance toward Florida for the day.
The trip resumed at 6:15 a.m. this morning as the carrier aircraft soared out of southern Kentucky, crossed Tennessee at 15,000 feet, dodged weather in Georgia and then cruised into Florida.
The pilots gave local Space Coast residents and visiting tourists a treat with a low-altitude pass along the beaches before arcing over the Atlantic and making the final approach toward the three-mile-long Shuttle Landing Facility runway.
The smooth touchdown on Runway 15 came at 8:27 a.m. EDT (1227 GMT), delivering Atlantis back to its homeport 25 days after blasting off with seven astronauts and a 36,000-pound power-generating module for the International Space Station. The highly successful spaceflight connected the new Starboard 3/Starboard 4 truss structure to the station and unfurled a pair of solar wings stretching 240 feet tip-to-tip.
"It is great to be here, back at the Shuttle Landing Facility with Atlantis," LeRoy Cain, manager of shuttle integration at Kennedy Space Center said from the runway this morning. "We had a very successful ferry mission across the country. It took us a few days, but it really went very well."
Atlantis will be plucked off the 747 later today and towed to its hangar as preparations begin for the ship's next flight, currently targeted for launch December 6 around 4:30 p.m. EST (2130 GMT). That mission will transport the European Space Agency's Columbus science laboratory to the station.
"Atlantis is in great shape, as you can see. We're really glad to have her back here and get her processed for the next mission in December," Cain said.
Meanwhile, sistership Endeavour has been raised vertically inside Kennedy Space Center's Vehicle Assembly Building for joining with an external fuel tank and twin solid rocket boosters atop a mobile launch platform. Endeavour was moved to the VAB from its hangar on Monday.
NASA plans to roll Endeavour to launch pad 39A early next week. Liftoff is scheduled for about 7 p.m. EDT (2300 GMT) on August 7, marking that orbiter's first flight in nearly five years.
Endeavour will bring up the small Starboard 5 truss spacer to the station for attachment to the segment just installed by the Atlantis crew. In addition, a Spacehab module riding in Endeavour's payload bay will be filled with a couple tons of food, clothing, supplies and spare parts to be carried through the hatchway and stowed inside the station.
Endeavour's crew includes educator-astronaut Barbara Morgan, backup to Challenger "teacher-in-space" Christa McAuliffe. Morgan is now a fully trained astronaut flying as a mission specialist.
___________________
Immagini qui: http://www.spaceflightnow.com/shuttle/sts117/070703ferrypix/
Dei 4 che erano previsti per la flotta del programma STS (Space Transportation System), ne rimangono 3:
- Discovery (OV-103), dove OV sta per Orbiter Vehicle
- Atlantis (OV-104)
- Endeavour (OV-105)
L'Enterprise è stato il primo (OV-101), doveva chiamarsi Constitution in onore del bicentenario della costituzione americana (correva l'anno 1976), ma era un prototipo non abilitato per il volo, poi fu costruito il Columbia (OV-102), il primo a volare (1981), poi fu la volta del Discovery (OV-103), e infine l'Atlantis (OV-104). L'Endeavour fu invece costruito per sostituire il Challenger (OV-99).
Oggi non sarebbe conveniente in termini di costi e ma anche come utiltà, anche perchè il programma dovrà essere chiuso e il resto degli orbiter mandati in pensione entro il 2011, causa scadenza della certificazione per il volo.
curiosando con Google Earth per il KSC (http://maps.google.it/maps?f=q&hl=it&geocode=&q=cape+canaveral,+fl&ie=UTF8&ll=28.525135,-80.680343&spn=0.001621,0.002811&t=h&z=19&om=0) ho trovato questo:
Explorer
http://static3.bareka.com/photos/medium/316038/kennedy-space-center-florida.jpg
http://en.wikipedia.org/wiki/Space_Shuttle_Explorer
Poi incuriosito ho trovato che esistono altri due:
Pathfinder
http://upload.wikimedia.org/wikipedia/commons/5/54/Space_Shuttle_Pathfinder.jpg
http://science.ksc.nasa.gov/shuttle/resources/orbiters/pathfinder.html
http://en.wikipedia.org/wiki/Space_Shuttle_Pathfinder
http://it.wikipedia.org/wiki/Space_Shuttle_Pathfinder
e America
http://upload.wikimedia.org/wikipedia/en/thumb/1/15/HPIM0896.JPG/800px-HPIM0896.JPG
http://en.wikipedia.org/wiki/Space_Shuttle_America
Qualcuno ne ha altri? :D :D
Scherzi a parte mi sono un po' perso su quali siano prototipi usati per tests o p per addestramento e quali siano semplicemente...fake
http://science.ksc.nasa.gov/shuttle/resources/orbiters/orbiters.html
l'unico originale (prototipo statico) è il Pathfinder, che fu utilizzato per i test a terra, mentre l'Enterprise era destinato al volo (detto appunto "flight-worthy") e venne utilizzato per i test in volo e di atterraggio.
Prometto che stasera apro la nuova discussione su la missione STS-118... intanto l'Endeavour è tornato sul pad dopo ben 5 anni di inattività e dopo il suo secondo ed ultimo OMMP (Orbiter Major Modification Program):
http://www.spaceflightnow.com/shuttle/sts118/070711rollout/
OT: non ricordo il nome di quel potente software per la visualizzazione in tempo reale della mappa del cielo stellato, compreso di pianeti, galassie nebulose etc etc, il software è molto grosso, credo che superi i 6GB di spazio su disco, l'avevo letto in un 3d di questa sezione ma non ricordo quale, se mi date una mano ... :sofico:
OT: non ricordo il nome di quel potente software per la visualizzazione in tempo reale della mappa del cielo stellato, compreso di pianeti, galassie nebulose etc etc, il software è molto grosso, credo che superi i 6GB di spazio su disco, l'avevo letto in un 3d di questa sezione ma non ricordo quale, se mi date una mano ... :sofico:
parli forse di Redshift ?
pubblicata su SpaceFlightNow un'interessante intervista a Mike Griffin amministratore della NASA.
ne riporto qualche stralcio:
Q: Aside from that, is the shuttle design fairly well frozen now with just three years left in the program?
Griffin: We pretty much have the design the way we think it needs to be. If we find something that isn't working, something that surprise us, of course we'll fix that. But from now until the end of the shuttle program, which is the end of space station assembly, with that one exception that we are going put in a change to the ice-frost ramps, I think we've got the vehicle where we want it.
Q: I know your position is that it's time to replace the shuttle and move on. But the shuttle will be missed, won't it? It's an amazing engineering achievement and it still inspires awe.
Griffin: Every time. It is a magnificent vehicle, it is an extraordinary creation of human beings and it's an extraordinary creation by Americans and we should be proud of what we've done. The fact that we need to put it behind us and move on, get back out into the solar system, return to the moon, go to Mars, if we're going to have a viable human spaceflight program we need to do those things. And the shuttle can't take us there. But that fact shouldn't allow us to miss the fact that the shuttle was an extraordinary creation, it offers immense capability and I think when it comes time to fly that last flight, it will have built a lot of nostalgia and a lot of feeling of loss among all people who have been part of the space program for their whole lives, as you and I have been in different roles.
http://www.spaceflightnow.com/shuttle/sts118/070807griffin/
personalmente mi pare di leggere tra le righe che Griffin non ami poi tanto gli Shuttles.
continuo a pensare che non sarebbe stata poi una cattiva idea continuare il progetto X33 (ormai ad uno stadio avanzato?) per le orbite LEO e sviluppare con piu' calma un vettore per le destinazioni piu' lontane.
Forse la mia e' solo nostalgia..
Non è che Griffin non ami lo Shuttle, anzi... da ingegnere lui più di chiunque altro sa quanto fantastica sia questa macchina (e infatti l'ha sempre sostenuto). Ma giustamente ha sollevato critiche specifiche al programma STS su come è stato creato e gestito, in particolare negli anni pre-Challenger... forse lo Shuttle non era la soluzione più pratica e, soprattutto, pià economica... infatti lo Shuttle ha si dimostrato che è possibile creare un mezzo rituilizzabile, ma non è riuscito a dimostrare allo stesso modo di poter essere economicamente sostenibile come si pensava, diventanto un flessibile mezzo commerciale per, ad esempio, sostenere lanci a distanza di poche settimane, periodi di turn-around brevissimi, ed essere il primo mezzo americano per la messa in orbita (e l'eventuale recupero) di satelliti... ;)
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parli forse di Redshift ?
no non è quello il nome, ricordo che si aveva una visuale da una costa di un lago e potevi tranquillamente filtrare la visualizzazione di stelle , pianeti etc etc. Si poteva impostare la visualizzazione in tempo reale del cielo stellato e impostare le coordinate della vostra città, installazione completata abbastanza grossa... 6GB.
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2235:42 GMT (6:35:42 p.m. EDT)
T-minus 1 minute. Computers are verifying that the main engines are ready for ignition. Sound suppression water system is armed. The system will activate at T-minus 16 seconds to suppress the sound produced at launch. And the residual hydrogen burn ignitors are armed. They will be fired at T-minus 10 seconds to burn off hydrogen gas from beneath the main engine nozzles.
Shortly, the external tank strut heaters will be turned off; Endeavour will transition to internal power; the liquid oxygen and liquid hydrogen outboard fill and drain valves will be closed; the payload bay vent doors will be positioned for the launch; and the gaseous oxygen vent arm will be verified fully retracted.
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Anche se ho dovuto litigare col gprs (managgia la mancata copertura dell'umts) che non mi dava più di 4 kBps, mi sono goduto il lancio dall'arrivo dell'equipaggio alla rampa di lancio.:eek:
Semplicemente strepitoso
:yeah: :yeah: :yeah:
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2239 GMT (6:39 p.m. EDT)
T+plus 2 minutes, 45 seconds. The twin Orbital Maneuvering System engines on the ship's tail have ignited to provide an extra boost in thrust in addition to Endeavour's three main engines.
Gio, e' una procedura normale che usino anche i propulsori di manovra? (o lo fanno solamente in casi di payload particolarmente pesanti)
Questi propulsori (se ricordo bene vanno a idrazina e tetrossido di azoto) non hanno una quantita' ridotta di combustibile/comburente?
By the way, stiamo postando sul thread generale del programma Shuttle. Non e' che possiamo chiedere a qualcuno dei moderatori di sessione di mettere i posts nella discussione giusta?
Marilson
10-08-2007, 11:04
hanno svegliato il crew per un problema con l'ossigeno :confused:
che è successo? :stordita:
URCA! adesso guardo!
un problema ad un regolatore di pressione del serbatoio di ossigeno 5.
Sono passati ad un controllo manuale.
Non sembra essere nulla di preoccupante, ne hanno fatta di strada dall'Apollo 13
porca troia mi son accorto adesso di aver postato per due giorni sul thread sbagliato! :muro: :muro: :muro:
Gio, e' una procedura normale che usino anche i propulsori di manovra? (o lo fanno solamente in casi di payload particolarmente pesanti)
Questi propulsori (se ricordo bene vanno a idrazina e tetrossido di azoto) non hanno una quantita' ridotta di combustibile/comburente?
in effetti sai che non mi ricordo... mi sembra strano... vengon utilizzati dopo il MECO per la separazione dall'ET ma prima durante il volo non mi risulta... sicuramente quella attuale non è una missione con un carico tra i più pesanti. Cmq mi informerò! ;)
By the way, stiamo postando sul thread generale del programma Shuttle. Non e' che possiamo chiedere a qualcuno dei moderatori di sessione di mettere i posts nella discussione giusta?
eh, difficile... intanto passiamo di là, vedrò di ricopiare i post più importanti! :doh::help: :muro:
ehm... carissimi moderatori... è possibile spostare i post dal #163 al #192 da questa discussione a questa (http://www.hwupgrade.it/forum/showthread.php?t=1511718)? :stordita: :help:
edit: fatto.
ore 18.03 GMT
Endevour/Iss docking effettuato con successo :)
ok, possiamo tornare qui (http://www.hwupgrade.it/forum/showthread.php?p=18243768) e continuare ad utilizzare questo thread per le news e le domande generali sul programma STS.
Grazie e scusatemi per il disguido! :O
Super Vegetto
10-08-2007, 21:02
E allora attenzione, che fra 15-20 minuti Shuttle e ISS ci passano sopra le teste (neanche tanto sopra poi, qui a Varese passano a Nord a 24° max di altezza)
Super Vegetto
10-08-2007, 21:05
E allora attenzione, che fra 15-20 minuti Shuttle e ISS ci passano sopra le teste (neanche tanto sopra poi, qui a Varese passano a Nord a 24° max di altezza)
Ho postato sia qui che di là perchè non avevo letto, continuiamo di là!;)
Scusate.:)
E' in fase di valutazione una nuova procedura per le prossime missioni STS mirata a prevenire la formazione di ghiaccio in particolari zone dell'External Tank.
Si tratta in sostanza di ridurre di mezz'ora il tempo che intercorre tra l'immissione dei combustibile e comburente criogenici e il lancio.
Questa procedura dovrebbe limitare il distacco di pezzi di ghiaccio e isolante dall'ET.
NASA plan to alter STS-120 launch countdown
By Chris Bergin, 9/9/2007 5:21:54 PM
Shuttle Launch Director Mike Leinbach has drawn up a plan to alter the countdown for the upcoming STS-120 launch of Discovery, with an aim to reduce ice build-up on the External Tank (ET).
The plan - which will go to the STS-120 Flight Readiness Review for full approval - involves reducing the T-3 hour hold by 30 minutes, added to ensuring the tanking process does not start before it is scheduled.
Ice, which is both a debris hazard and a mechanism for liberating foam off the ETs during ascent, builds up on the tank when it's filled with the super-cold liquid oxygen and liquid hydrogen ahead of launch.
To mitigate ice build-up, the tanks are covered in foam insulation. However, that foam can liberate off the tank during ascent due to the massive aerodynamic stresses the stack undergoes on the ride uphill.
Finding the balance of reducing the amount of foam that can liberate off the tank, versus what is required for thermal protection, has been an ongoing process for NASA, especially after the loss of Columbia.
Another problem relates to small areas of ice that can still build-up in certain areas of the tank. One such area is in the small gaps inside the five LO2 feedline brackets, required to allow the 17 inch diameter pipe to flex as thousands of gallons of propellant are sucked towards the orbiter's main engines.
Those brackets have previously shed foam, but only came into focus after a liberation event 58 seconds into the launch of Endeavour during STS-118.
Rather unluckily, the piece of foam - along with what was believed to be some of the denser underlying SLA (Super Lightweight Ablative) - bounced off the aft strut of the tank, before rebounding on to Endeavour's belly, causing a gouge that took several days of evaluations before being cleared as no threat to the orbiter's re-entry.
No damage was suffered by Endeavour's structure once the tiles were removed after landing.
That liberation event has been classed as directly related to ice build-up in the area of the bracket, officially listed as 'mechanically induced cracking of the foam (due to ice bridging) and aeroshear.'
While X-ray tests - called on the next tanks set to fly - determined that cracks already existed in four of ET-120's (STS-120) brackets, along with one on ET-125 (STS-122), ultimately causing the repair of the brackets, NASA have a plan to reduce ice build-up that can occur on the brackets in the first place.
**Ride home through the fire, sparks and plasma of re-entry with Atlantis, Discovery and Endeavour. FOUR Stunning high quality 2hr, 355-400mb Camcorder and HUD videos - from payload bay closure - through re-entry with a astronaut held camcorder video - to post landing - several more videos showing landing from 90,000 ft also available**
The plan, which was hinted at just a few days after STS-118, relates to the earlier-than-scheduled tanking of STS-118's tank, which is believed to have caused slightly more ice to form on the brackets ahead of launch. This will be mitigated by a two-pronged plan created by Leinbach.
That plan is based around reducing the time between tanking and launch (T-0), whilst keeping to within safety requirements of the countdown.
Finding a way of reducing that timeline evaluated all three of the main built-in holds during final part of the countdown - namely: the three hour hold at T-3 hours. The 10 minute hold at T-20 minutes and the 40 minute hold at T-9 minutes.
Leinbach's recommendation is to remove 30 minutes from the hold at T-3 hours, which, as a result, would then become a two hour, 30 minute hold.
'This is a launch probability question, NOT a safety issue as all documented inspections will still be performed,' Leinbach stressed in his recommendation, before adding his rationale.
'Eliminate early tanking - no impact to planned timelines. Will hold ET load sequencer initiation until T-6 hrs and counting. Provides contingency to protect ET load start time at T-6 hrs.
'Reduce hold time at T-3 hrs from 3 hrs to 2.5 hrs - No impact to the FIT (Final Inspection Team) timeline or inspection requirements. Since RTF-2 (STS-121) on-pad inspection timelines have averaged 2 hrs 24min (low 2 hr 6 min - high 2 hr 50 min). For Flight Crew arrival at Pad with FIT inspection in work. Reduced disposition time seen as acceptable by Technical Community.'
'No change to other holds at T-20 and T-9 min. Not advisable from clock management perspective. Further recommend that the STS-120 LCD is structured with the changes noted and to review post-test for lessons learned. Suggest no further changes without clear evidence that additional time reduction will not significantly impact launch probability.'
The presentation (available on L2) - with a new timeline chart showing the new countdown procedure - does not make it clear if the actions are now baselined into the STS-120 countdown, although it is - as with all changes to a launch - set to go in front of the Flight Readiness Review (FRR) for approval, should it be required.
la pagina di riferimento:
http://www.nasaspaceflight.com/content/?cid=5224
Continua la preparazione della missione STS-120 anche se con qualche intoppo:
Problem could delay shuttle Discovery's launch
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: September 16, 2007
Engineers are assessing an apparent hydraulic leak in the shuttle Discovery's right-side main landing gear strut. If internal seals have to be replaced, launch on a space station assembly mission could slip a few days, officials said today, but they cautioned that it's not yet clear how long such repairs might actually take.
The leak was discovered during routine testing in preparation for the shuttle's rollover from its processing hangar to the Vehicle Assembly Building for attachment to an external fuel tank and solid-fuel boosters. As of Friday, rollout to launch pad 39A was targeted for Sept. 27, setting the stage for launch Oct. 23.
But work to replace the hydraulic seals, if required, would delay rollover and rollout. Even with several days of contingency time in the schedule, launch could be delayed a few days if repairs are ordered. What impact, if any, such work might have on plans to launch the shuttle Atlantis around Dec. 6 is not yet known.
NASA and contractor managers plan to meet Monday to discuss the issue and make a decision on how to proceed.
il link si spaceflightnow:
http://www.spaceflightnow.com/shuttle/sts120/070916leak/
e l'articolo su NasaSpaceFlight:
http://www.nasaspaceflight.com/content/?cid=5229
attendiamo GioFX per la consueta apertura del thread dedicato alla missione ;)
Shuttle launch date stays on track after quick repairs
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: September 20, 2007
Work to replace suspect hydraulic seals in the shuttle Discovery's right main landing gear is going smoothly and barring additional problems, NASA managers said today, the shuttle should be ready for blastoff Oct. 23 as originally planned.
http://www.spaceflightnow.com/shuttle/sts120/070920repairs/strut.jpg
Credit: NASA-KSC
Engineers now plan to roll Discovery from its processing hangar to the Vehicle Assembly Building for attachment to an external fuel tank and two solid-fuel boosters early Sunday. If all goes well, the orbiter will be moved to launch pad 39A on Sept. 30, three day later than originally planned.
The initial repair schedule was typically conservative, predicting up to a week and a half of work to replace and retest suspect hydraulic seals in the right main landing gear strut that absorbs the shock of touchdown. Even though only one of four seals was thought to be leaking, managers decided to replace them all to be on the safe side. That work went faster than expected and testing should be complete by Saturday.
NASA had several days of contingency time built into the processing schedule before the hydraulic leak was discovered last week. As it now stands, engineers hope to still have one day of contingency time left in the on-pad flow to handle any unexpected problems that might crop up.
This shot shows a worker replacing one of the seals. Credit: NASA-KSC
The goal of Discovery's five-spacewalk mission is to reposition a set of solar arrays and install a new multi-hatch module that will serve as the attachment point for European and Japanese research modules. NASA hopes to close out the year by launching the European Space Agency's Columbus module aboard the shuttle Atlantis on Dec. 6.
Ongoing work to fix corrosion and other problems with the huge doors of the Apollo-era Vehicle Assembly Building had limited NASA to a single high bay for shuttle processing. But work on the doors of a second high bay is wrapping up ahead of schedule and officials say the delay getting Discovery to the pad will have no impact on the December mission.
la pagina di Spaceflightnow.
http://www.spaceflightnow.com/shuttle/sts120/070920repairs/
L'articolo su NasaSpaceFlight:
http://www.nasaspaceflight.com/content/?cid=5235
grazie oct... stasera o domani mattina apro il thread sull'STS-120.
;)
Da SpaceFlightNow.com:
Atlantis flying to 2010, Hubble slightly delayed - manifest re-aligned
By Chris Bergin, 1/16/2008 12:41:51 AM
The official decision on the future of Atlantis has finally been made, as she avoids early retirement in 2008 - gaining STS-128 and STS-131 in the process via new planning documentation.
Atlantis' flagship mission - STS-125's trip to service the Hubble Space Telescope - has been delayed by one month, to September 5, as the bulk of the manifest moves to the right by around 30 days, due to the slip of STS-122 to February 7.
As with all schedules, planning documentation is drawn up for the benefit of mapping out processing flows. However, given the delay to STS-122, the re-aligned dates had to be created, mainly due to the requirement of needing two 'flight ready' shuttles in time for STS-125's launch.
The short term schedule, as previously reported, shows the three upcoming flights as Feb 7 (STS-122), March 13 (STS-123) and April 24 (STS-124) - all achievable as the orbiter processing flows continued reasonably unhindered, while STS-122 continues its return from ECO (Engine Cut Off) sensor anomaly troubleshooting.
However, while Atlantis would still be on track to make the previous August date for her mission to Hubble (STS-125), the unique LON (Launch On Need) requirement of having Endeavour sat on Launch Pad 39B as the rescue shuttle, has led to a refinement of the launch dates.
'Parallel Processing' of Atlantis and Endeavour is key to STS-125, with Atlantis coming out of post flight processing from STS-122, and Endeavour returning from STS-123 - the latter for a triple requirement of being the LON orbiter for STS-124, the LON orbiter for STS-125, and then prepared for her primary mission of STS-126.
Endeavour's Hubble rescue mission role will see her rolled out to 39B for the last time a shuttle will sit on that pad, as modifications - some of which have already started - are made ahead of the test flight of Ares I-X in 2009.
Being ready to launch at short notice is required, due to Atlantis' mission to Hubble being the only flight on the remaining manifest without the 'safe haven' of the International Space Station (ISS).
Any critical damage to Atlantis, and Endeavour - along with a four man crew - would be required to carry out a unique on-orbit rescue of the crew, within a maximum of three weeks.
Once stood down from her rescue requirements during STS-125, Endeavour will be rolled over to 39A, to be prepared for STS-126 - itself a key mission for ISS expansion, while also carrying out a special re-entry experiment. This flight is now scheduled for October 16.
STS-119 with Discovery, carrying the S6 integrated truss segment, moves from November 6 to December 4, as NASA managers still aim to pull off six flights in 2008.
'If launch dates hold up, and I expect most will, we will fly six shuttle flights in CY '08,' noted Flight Director Cathy Koerner this week. 'There'll be five flights to ISS; four of which will bring new elements and two of those will add new international partners to the mix.
'Throw in one exciting and challenging repair mission for the Hubble Space Telescope and we have the makings for an amazing year in human spaceflight!'
The delays to these short-term missions should not be seen as negative, especially when taking into account that at one point last year STS-125 was tracking a launch date of September 11.
Atlantis has been officially saved from an ungraceful retirement of becoming a spare parts donor/bin for her two sisters, as the long-planned extension to her operating lifetime was announced by Orbiter management to their respective engineering teams earlier this month.
The decision, which had to go through NASA HQ and the Space Shuttle Program (SSP) management for approval, has been long in the planning, since this site revealed the drive to reverse the original retirement date, in the middle of last year.
Now, finally, Atlantis' two extra flights are documented in both planning schedules and processing flow documentation, handing the challenge to ever-capable United Space Alliance (USA) engineers who care for the three ships during processing.
Once returned from STS-125, she will enjoy an extended stay inside OPF-1 (Orbiter Processing Facility) - as she regains her ODS (Orbiter Docking System) that will be removed for her mission to Hubble, along with the addition of the SSPTS (Station-Shuttle Power Transfer System) modification, allowing Atlantis to carry out extended ISS missions.
Atlantis originally had no choice but to retire in 2008, given she was due for her OMDP (Orbiter Maintenance Down Period) by that time. The overhaul - which can take over a year to complete - would have been deemed pointless, with only another year of shuttle operations to follow her return to flight status.
However, in the middle of last year, engineers devised a priority list of work that was required on Atlantis, creating 'mini-OMDP' processing which could be conducted inside the OPF during regular post and pre-flight flows.
Titled the '3 year / 8 Flight OMRSD (Operations Maintenance Requirements Specifications Document) Review,' the option was added to extend orbiter's flight status in-between OMDPs to eight flights and five and a half years - instead of the previous three years, based on timelines that do not include delays induced by other orbiters 'getting in the way.'
Ultimately this needed to be approved, as only Endeavour was able to fly until 2010 under the previous definitions, as some elements of the plan are adopted into Discovery's processing flows. However, the main focus was on Atlantis, in order to find a way to reverse her 2008 retirement.
Immediately after the review, a FAWG (Flight Assignment Working Group) manifest handed two extra missions to Atlantis, before being withdrawn, as official approval was sought via a combination of NASA HQ and SSP - mainly relating to approving additional costs associated with flying three orbiters through to the end of the manifest.
Adding weight to the argument, another presentation was produced in August of last year, refining the OMRSD data, whilst pointing out the importance of flying out the schedule with three orbiters, so as to ensure an on time transition of shuttle resources to Constellation.
The latest manifest shows Atlantis returning with STS-128, which follows Endeavour's STS-127 flight - which is a refined five EVA mission that has moved to April 23, 2009.
STS-128, targeting July 16, 2009, will see Atlantis return after over eight months inside OPF-1 - taking into account the completion of STS-125 and rollover for STS-128 - before being handed another final honor, as she becomes the last orbiter to carry out a crew rotation with the ISS.
Discovery and Endeavour will then fly out 2009 with STS-129 (moved to September 3) and STS-130 (moved to October 22) respectively, completing a four mission calendar year.
Atlantis then flies her final mission, STS-131, currently moved from 2009, to January 21, 2010 - the first of two optional CLF (Contingency Logistic Flight) missions, sandwiched in-between is Discovery's final flight, STS-132 (Node 3) - moved to March 18, 2010, with Endeavour's STS-133 - the second CLF mission, moved to April 29, 2010, ending the manifest.
It should be noted that this is the current plan, created after the slip of STS-122 to NET (No Earlier Than) February 7. However, all subsequent flights are at the mercy of both mission success (any additional post-flight processing) and other factors such as hardware issues, or even the weather.
Currently, the goal is to fly out the remaining missions by April 2010, though this date can be reviewed as the missions are flown, due to the in-built flexibility for unforeseen circumstances.
It is understood that both CLF missions will be flown, so as to aid the ISS after the loss of the shuttle supply line. Further refinements to the manifest will be reported as documentation is acquired.
___________
Articolo: http://www.nasaspaceflight.com/content/?cid=5333
alla fine pare che abbiano trovato il modo per far volare gli shuttles piu' a lungo per colmare il gap che si verra' a creare prima dell'arrivo di Constellation.
Ipotizzo che alla base di questo ci possa essere anche la consapevolezza che, per gli Stati Uniti restare senza vettori (per il trasporto umano) per cosi' tanto tempo sarebbe uno smacco notevole, visto che in orbita ci arrivano i Russi e..i Cinesi..
Tornando agli shuttles, che modifiche apporteranno all'Atlantis nel mini-ODMP?
Marilson
16-01-2008, 21:58
è probabile una riduzione della flotta? secondo me fanno fuori il discovery, tengono l'altantis e l'endevour alternandoli per avere sempre il backup in caso di emergenza.. 2 shuttle sono il numero ideale anche per mantenere i costi, presumibilmente il discovery verrà anche cannibalizzato per i pezzi di ricambio.. :rolleyes:
albertoz85
16-01-2008, 22:05
è probabile una riduzione della flotta? secondo me fanno fuori il discovery, tengono l'altantis e l'endevour alternandoli per avere sempre il backup in caso di emergenza.. 2 shuttle sono il numero ideale anche per mantenere i costi, presumibilmente il discovery verrà anche cannibalizzato per i pezzi di ricambio.. :rolleyes:
No, come è scritto sopra andranno tutti e tre in pensione quasi in contemporanea nel 2010 con le missioni STS-131, STS-132 e STS-133 rispettivamente Atlantis, Discovery ed Endeavour.
Infatti, se leggete è scritto chiaramente nell'articolo. Non cambia nulla rispetto a prima, rimanendo fissa l'imprescindibile data della fine del programma STS con l'anno fiscale 2010, salvo per il fatto che l'Atlantis continuerà a volare fino all'aprile dello stesso anno e "conquistando" altre due missioni (voli logistici - ULF - già previste dal Manifest, ma fino ad oggi assegnate rispettivamente all'Endeavour, 128, e al Discovery, 131).
L'idea iniziale di utilizzare l'Atlantis, che nel corseo del 2008 avrebbe dovuto entrare nel suo terzo OMDP (Orbiter Maintenance Down Period) rendendo di fatto inutile il suo ritorno al volo per 1 o 2 missioni nel 2010, è stata cambiata predisponendo un mini-OMDP per permettere all'Atlantis di poter volare fino al termine del programma e quindi consentendo alla NASA di poter sfruttare un tournaround più rapido e mantenere la frequenza attuale di circa 5 missioni all'anno per garantire il termine della costruzione dell'ISS (avendo a disposizione tutti e tre gli orbiter rimanenti).
Oltre a questo non è attualmente prevista alcuna estensione del termine del 2010 per il ritiro della flotta e la fine del programma, dato che TUTTI gli orbiter dovrebbero, dopo il 2010, essere totalmente ricertificati per il volo, operazione questa che costerebbe decine di milioni di dollari (non previsti dal budget per il programma STS e che se richiesti andrebbero a drenare ulteriormente i già elevatissimi costi del programma Constellation).
In ricordo del Columbia e del suo equipaggio, nel 5° anniversario:
SpaceFlightNow.com:
STS-107 Mission Report: http://www.spaceflightnow.com/shuttle/sts107/
STS-107 Mission Status Center: http://www.spaceflightnow.com/shuttle/sts107/status2.html
"Comm Check...The Final Flight of Shuttle Columbia", Chapter 1: http://www.spaceflightnow.com/shuttle/sts107/040201commcheck/
Space.com:
Columbia Commander's Widow Rebuilds Life After Tragedy: http://www.space.com/news/ft-080201-columbia-widow.html
Columbia's Legacy Drives NASA Shuttle Flights: http://www.space.com/news/080201-columbia-legacy.html
Da NasaSpaceFlight.com:
Shannon takes over from Hale as Shuttle manager
By Chris Bergin, 2/22/2008 1:18:25 PM
John Shannon has become the new Space Shuttle Program manager, following Wayne Hale's departure to the role of NASA's deputy associate administrator for strategic partnerships.
Shannon moves from the deputy position to take up the reins of the program that has achieved eight safe shuttle missions - under Hale as both deputy and manager of the program - since taking up the challenge of Return To Flight.
Hugely respected, Hale began his career with NASA in 1978 as a propulsion officer in the Propulsion Systems Section, Flight Control Division of Flight Operations at the Johnson Space Center.
From May to November 1985, Hale was head of the Integrated Communications Section, Systems Division, Mission Operations, and head of the Propulsion Systems Section, Systems Division, Mission Operations, from November 1985 to March 1988.
Between March 1988 and January 2003, Hale served as a flight director in Mission Control for 41 Space Shuttle missions. He also served as deputy chief of the Flight Director Office for Shuttle Operations from 2001 to January 2003.
Hale then relocated to Kennedy Space Center to become the launch integration manager of the Space Shuttle Program effective February 1, 2003. Since the loss of Columbia, Hale moved to the role of deputy shuttle manager in July of 2003, before becoming the program manager in September 2005.
One of the most quotable managers at NASA, Hale is well known for giving calm and expansive answers to media questions, while also noted for writing some of the most inspirational memos during his time with the shuttle program.
'This is probably a good time to remember what we are about and why we do it. We are in the business of sending people into space. Nothing more and nothing less. Actually there is quite a bit more, but certainly nothing less,' wrote Hale in one memo to the program not long after the loss of Columbia. (A large collection are available on L2.)
'Space exploration - like all exploration - is about the human spirit. What is over the next hill? Antarctica and the depths of the oceans are no longer untouched and unimaginable. To inspire our young people and motivate our nation, the only objective is up.
'The new version of manifest destiny is to explore the universe. We go into space not merely because it helps us economically, or fosters building new and improved gadgets; we go into space because that experience fulfils the nature of what it means to be human.
'Enabling human hands to reach out and touch the universe is a goal worthy of the danger and sacrifice that human space flight has required.
'We have certainly endured trials this year and we can expect more ahead of us. As we go into the next few days, I would offer these words of the great baseball player 'Babe' Ruth: 'It's hard to beat a person who never gives up.'
Shannon was selected as the head of Space Shuttle Guidance, Navigation and Flight Control in 1992 and became a space shuttle flight director in 1993, supporting 58 shuttle missions. He holds the distinction of being the youngest flight director in NASA history.
After serving as deputy director of the Columbia Task Force in 2003, Shannon was selected to create the Space Shuttle Program's Flight Operations and Integration Office.
Hale orginally claimed he would remain in the role until 2010. However, in Shannon, the program has a capable replacement.
Shannon takes over as program manager in time for the upcoming STS-123 Flight Readiness Reviews (FRR) next week.
http://www.nasaspaceflight.com/content/?cid=5364
Hubble servicing mission's launch date threatened
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: March 21, 2008
With the shuttle Endeavour's mission entering the home stretch, shuttle Discovery remains on track for blastoff May 25 to ferry a huge Japanese laboratory module to the international space station. But subsequent near-term flights, including a high-profile mission to service the Hubble Space Telescope, could be delayed, sources say, because of ongoing external tank production issues.
l'articolo intero:
http://www.spaceflightnow.com/shuttle/sts123/080321tanks/index.html
Da NasaSpaceFlight.com:
Atlantis' STS-125 mission to Hubble delayed to October
By Chris Bergin, 4/4/2008 11:11:48 PM
The Michoud Assembly Facility (MAF) has completed a re-evaluation of the delivery dates for ET-127 and ET-129. The two tanks directly relate to the launch date target for STS-125 - the final servicing mission to the Hubble Space Telescope - and the LON-400 rescue mission contingency.
As a result of the evaluations, STS-125 has been delayed to October, STS-126 to November and STS-119 to February, 2009.
---
Articolo:
http://www.nasaspaceflight.com/content/?cid=5396
STS-124 payload awaits Discovery at Pad 39A - Fleet update
By Chris Bergin, 4/30/2008 11:37:27 AM
http://www.nasa.gov/images/content/224705main_image_1073_346-260.jpg (http://www.nasa.gov/images/content/224709main_image_1073_946-710.jpg)
Image Credit: NASA/Jim Grossman
The huge Japanese Pressurized Module (JPM) has been transferred to Launch Pad 39A, ahead of Saturday's rollout of shuttle Discovery - as STS-124 preparations enter the final stretch ahead of May 31's launch date.
Meanwhile, evaluations are continuing on the next two External Tanks (ET-127 and ET-129) - which are still undergoing production at the Michoud Assembly Facility (MAF) - as shuttle managers debate as to when they will be able to launch the final servicing mission to Hubble.
l'articolo completo:
http://www.nasaspaceflight.com/content/?cid=5414
http://www.nasa.gov/images/content/224318main_124_rollover_690.jpg
http://www.nasa.gov/mission_pages/shuttle/main/index.html
Attendiamo, come di consueto, l'apertura da parte di GioFX del thread dedicato alla la missione STS-124 ;)
Eccomi, scusate ma ero in viaggio (NYC)... :D
Appena posso apro il thread sull'STS-124! ;)
Ulteriori cambiamenti al manifest. Gran parte delle prossime missioni slittano di qualche settimana (fino ad un paio di mesi) essenzialmente per i ritardi di produzione degli External Tanks.
Manifest Changes:
As exclusively revealed by this site back in April, STS-125's move to October 8 - and the subsequent slip of STS-126 to November 10 - immediately moved STS-119 to February 12, 2009, though the latter was only made official in the manifest on Monday.
Discovery's STS-119 flight recently gained its opening planning documentation, created for the mission that will carry the final truss element (S6) to the International Space Station (ISS).
The expansive mission baseline includes documentation on the deferred Boundary Layer Transition (BLT) experiment that was originally scheduled for STS-126, plus a special Thrust Oscillation test - designed to provide valuable launch vibration data for Ares I.
With STS-119's slip from December, 08 to February, 09 now confirmed, the program refined the remaining manifest to align with the required spacing between missions.
'The Shuttle Program has released a manifest CR (Change Request) to update launch dates for STS-119/15A, STS-127/2JA, and STS-128/17A and have an updated manifest to reflect planning dates for the rest of the program,' noted documentation acquired by L2.
'External Tank delivery dates are still the long pole but they are hopeful they will be able to meet the schedule.'
Endeavour's STS-127 mission will complete assembly of the Kibo Laboratory complex, and has now been moved from April 23, 09 to May 21.
Endeavour will launch with a complex array of payloads that will require a 15 day mission with five baselined EVAs. Aside from installing the Japanese Experiment Module - Exposed Facility (JEM-EF), Endeavour's crew will be tasked with replacing six batteries on the P6 truss.
STS-128 - now flying with Atlantis following her release from a 2008 retirement - is a logistics run to the ISS that has a new launch date of July 30, which is only a slip of a couple of weeks.
Atlantis' primary payload will be the Multi-Purpose Logistics Module (MPLM) 'Donatello' - which will boost the ISS' capability to deal with the increased crew of six astronauts.
Atlantis is scheduled to transport NASA astronaut Nicole Stott to the ISS for her role on Expedition 19, while returning US Army Colonel Timothy Kopra from his stay on the Station. Stott will return on a Russian Soyuz.
'STS-128/17A was baselined with a 7/30/09 launch date, consistent with the manifest CR,' added documentation. 'STS-128 is on OV-104 (Atlantis), which does not have SSPTS (Station-To-Shuttle Power Transfer System) so the baselined mission duration is 11+1+2 with two planned EVAs.
'The cargo bay complement includes an MPLM and an Ammonia Tank Assembly (ATA) installed on a Lightweight MPESS Carrier (LMC). The TriDAR Automated Rendezvous and Docking Sensor DTO-701A is also planned for STS-128.
'The depleted ATA and the external ESA payload, European Technology Exposure Facility (EuTEF), installed during STS-122/1E, will return on the LMC and two Materials on International Space Station (MISSE) carriers (6a and 6b) will return on a sidewall carrier.'
The documentation also noted the evaluations that are considering leaving Donatello on the ISS - though this is currently not been decided.
'ISS is considering whether they want to leave the MPLM on orbit but the current baseline has it returning. This flight is planned to be the first flight of the OI-34 software and the last flight to launch a rotating ISS crewmember.'
The manifest realignment also brought up an interesting element of flexibility, which references the evaluations into allowing launch dates that would see an orbiter docked to the ISS at the same time a Soyuz docks.
Known as Soyuz 'cutouts' - it is currently a constraint for orbiters, due to the potential of a Soyuz auto-abort during approach, when the Russian vehicle's Kurs docking system fails to see the docked orbiter - thus becoming a potential collision threat.
'You'll note launch dates during what previously have been considered Soyuz 'cutouts', added the documentation. 'For example, STS-127/2JA is scheduled to launch on 5/21/09 and Soyuz is scheduled to dock on 5/27/09.
'The SSP has requested that the ISS and MOD (Mission Operations Directive) reassess Soyuz dockings and undockings while the Shuttle is docked to improve Shuttle launch flexibility.
'The GJOP (Generic Joint Operations Panel) has been asked to review previous assessments, identify what assumptions are now different, and determine whether it makes sense to plan for a Soyuz docking or undocking during a Shuttle mission.'
The re-evaluation has been called due to the expansion of the ISS, which has increased the distance between the docking ports of Soyuz and Shuttle at either 'end' of the Station. If the evaluations recommend the constraint remains in place, the launch dates will be again refined.
'The thought process is that the answer may be different now that the Shuttle and Soyuz docking ports are farther away and ISS will be doing 'indirect handovers' - new crew coming up on Soyuz will be with three of the previous crew for an extended duration rather than the current short term intense handover period.'
Realigning with the new manifest are the remaining five missions in the latter half of 2009 and the 2010 finale.
STS-129 slips to October 15, 09. The mission will see Discovery carrying the EXPRESS Logistics Carriers ELC1 and ELC2, and will involve a crew rotation of Expedition 20's Robert Thirsk with his replacement, Jeff Williams.
STS-130 slips six weeks to December 10, 2009. Endeavour is carrying the final major element of the ISS in Node 3, along with the ESA-built observatory module Cupola.
Three missions are currently scheduled for 2010, opening with Atlantis' second mission to be added since her stay of execution - STS-131 - which is a logistics run to the ISS.
Atlantis' mission - which has moved to February 11, 2010, involves the final flight of a Multi-Purpose Logistics Module, namely Raffaello. No mention of its potential stay on the ISS has been made at this time.
The two remaining missions - at present - for the shuttle program are the CLF (Contingency Logistic Flight) missions, tasked to Discovery and Endeavour.
Changes to these two missions see STS-132 move to April 8, 2010, while the finale to the program has been moved to the right by one month, as Endeavour flies to the ISS on May 31, 2010.
Officially removed from the long-term manifest are the specific Launch On Need (LON) requirements. The rescue capability remains throughout the remainder of the program, but instead of requiring a specific flow in the event of an emergency, the following launch date will be close enough to carry out the contingency.
'Note that the new Launch on Need approach is to use the next flight with the planned cargo complement to rescue the previous flight if necessary (i.e. concept of STS-3xx's is going away).'
fonte: NasaSpaceFlight.com
http://www.nasaspaceflight.com/content/?cid=5457
ancora altre opinioni riguardo il ritiro dal volo degli Shuttle:
Captain Cernan calls for shuttle extension over gap concerns
By Chris Bergin, 6/30/2008 5:56:54 PM
Captain Eugene (Gene) Cernan, the last man to walk on the moon, has called for the shuttle to be extended past 2010 - so long as it doesn't damage Constellation's manifest - in order to reduce the gap in US manned space flight capability.
In an inspiring interview, Captain Cernan spoke on a variety of topics, ranging from his concerns about presidential candidate Barrack Obama's plans for NASA, to his wish that he had flown the space shuttle.[...]
l'articolo e' lunghetto ma merita la lettura:
http://www.nasaspaceflight.com/content/?cid=5462
Probabile cmq che si vada a qualche tipo di prolungamento per almeno uno degli orbiter (Discovery), ma è ancora presto per dirlo.
Probabile cmq che si vada a qualche tipo di prolungamento per almeno uno degli orbiter (Discovery), ma è ancora presto per dirlo.
sempre restando sull'ipotetico, perche' il Discovery? perche' non Endeavour visto che e' anche l'ultimo ad aver fatto l'ODMP?
sempre restando sull'ipotetico, perche' il Discovery? perche' non Endeavour visto che e' anche l'ultimo ad aver fatto l'ODMP?
Mi pare di ricorda che, oltre al fatto che sarà l'ultimo orbiter a volare secondo il manifest attuale (STS-132), Discovery è preferito ad Endeavour come primo orbiter utilizzabile.
In ogni caso, qual'ora venisse esteso il finanziamento al programma e venisse rilasciata una nuova certificazione, sarebbe per 2 orbiter in stato di flight-ready, ma verosimilmente solo 1 volerebbe.
FlatEric
02-07-2008, 00:31
Anche perché come si legge da, ad esempio, la pagina wiki dell'Atlantis:
NASA announced that 24 helium and nitrogen gas tanks, named Composite Overwrap Pressure Vessels, in Atlantis are older than their designed lifetime (designed for 10 years, later cleared for another 10 years but in service now for 22 years). NASA said it cannot guarantee any longer that the vessels on Atlantis will not burst or explode under full pressure. Therefore, the vessels will only be at 80 percent pressure as close to the launch countdown as possible, and the launch pad will be cleared of all but essential personnel when pressure is increased to 100 percent. A launch pad explosion could damage parts of the shuttle and even wound or kill ground personnel. An in-flight failure to the vessels could even result in the loss of the orbiter and its crew. Because the original vendor is no longer available, the vessels cannot be rebuilt before 2010, when the shuttles are scheduled to be retired. NASA analyses originally assumed that the vessels would leak before they burst, but new tests showed that they would burst before they leak. The new launch procedure, of clearing the launch pad of all but the essential personnel and pressurizing the tanks to 100 percent as late as possible, will now be conducted during the remaining Atlantis launches if no other resolution is found. Atlantis will have to fly at least one more time in this setting. It is unclear, but possible, that Discovery, which will launch another five or six times, has the same problems and if the same launch procedure needs to be conducted with Discovery. Since Endeavour, which will launch another six or seven times, was built much later, around 1990, it is possible that Endeavour does not have the same problem.
E quindi con questo problema di serbatoi le missioni sarebbero sempre più rischiose, a meno di rifarli (immagino a prezzi esorbitanti ed antieconomici, dato che andrebbe rifatta la catena di produzione per il fallimento dell'azienda produttrice originale)
e' ufficiale il nuovo manifest delle missioni STS:
http://www.spaceflightnow.com/shuttle/sts125/080707manifest/shuttlelaunch.jpg
Credit: Chris Miller/Spaceflight Now
Here is the revised manifest:
2008
* 10/08/08: STS-125/Atlantis
Hubble Space Telescope Servicing Mission No. 4; 5 spacewalks
* 11/10/08: STS-126/Endeavour/ISS-ULF2
Starboard solar array rotary mechanism servicing; logistics/resupply; 4 spacewalks
2009
* 02/12/09: STS-119/Discovery/ISS-15A
S6 solar arrays; 4 spacewalks
* 05/15/09: STS-127/Endeavour/ISS-2JA
Kibo Exposed Facility; solar array batteries; 5 spacewalks
* 07/30/09: STS-128/Atlantis/ISS-17A
Multi-purpose logistics module; lab racks; 3 spacewalks
* 10/15/09: STS-129/Discovery/ISS-ULF3
Spare gyros, other spares; at least 3 spacewalks
* 12/10/09: STS-130/Endeavour/ISS-20A
Node 3 connecting module, cupola; at least 3 spacewalks
2010
* 02/11/10: STS-131/Atlantis/ISS-19A
Multi-purpose logistics module; science racks; at least 3 spacewalks; Atlantis' last flight
* 04/08/10: STS-132/Discovery/ISS-ULF4
Russian research module; spares; at least 3 spacewalks; Discovery's last flight
* 05/31/10: STS-133/Endeavour/ISS-ULF5
Spares; at least three spacewalks; Endeavour's last flight
l'articolo: http://www.spaceflightnow.com/shuttle/sts125/080707manifest/
il manifest in dettaglio: http://www.spaceflightnow.com/shuttle/sts125/080707manifest/manifest.html
e il manifest combinato STS/ISS: link (http://www.spaceflightnow.com/shuttle/sts125/080707manifest/manifest.gif)
Blog (http://blogs.nasa.gov/cm/blog/waynehalesblog/) di Wayne Hale.
Naturalmente è in inglese, però gli interventi sono molto interessanti.
Torna ad affacciarsi, ancora una volta, la possibilità che gli Shuttles vengano fatti volare fino al 2015:
Shuttle Extension Assessment:
Mr Shannon also made a reference to a large scale study that started this week (memos and letters on L2) relating to the possibility of keeping the shuttle fleet flying through to 2015.
The primary reason noted relates to manned access to the International Space Station (ISS), which is currently tasked to the Russian Soyuz vehicle for around five years, from 2010 when shuttle is due to retire, to 2015 when Orion reaches IOC (Initial Operational Capability).
However, doubts remain on whether that is achievable - with notes (L2) showing the Orion Preliminary Design Review (PDR) is being delayed again - possibly by six to 12 months.
The concern is based on the recent disagreements between the US and Russian over the Georgian conflict, and any potential fallout relating to extending the Iran/North Korea/Syria Agreement (INKSA) Waiver.
This waiver is required to allow NASA to purchase Soyuz flights through 'the gap', thus retaining a US presence on the ISS. Should political tensions continue between the US and Russia, the resulting possibility of losing access capability is a major concern to NASA.
'The Iran/North Korea/Syria Agreement (INKSA) Waiver expires in 2011. While this sounds far off, due to the three-year lead-time required for Soyuz production, this issue is a pressing matter now,' noted Mr Shannon on the latest Shuttle/Stand-up/Integration report.
'The question to be answered is: if the waiver is not extended, how will we return our astronauts from the ISS? How will this affect U.S. presence on the ISS? This topic is at the front of everyone's mind due to the conflict between Russia and Georgia.'
Several potential solutions could be initiated - such as an additional COTS (Commercial Orbital Transportation Services) effort based around manned access to the ISS - though only the shuttle can provide immediate confidence in being able to carry out the required tasks.
As a result, the assessments are based solely on evaluating whether shuttle can safely continue flying through the gap - or until a short term solution can follow on from shuttle, until Orion is ready to take over the role.
Issues with extended shuttle are obvious, ranging from using the vehicles in a reduced capability - as an ISS taxi, the major budgetary challenge of continuing to push forward with Constellation development, and the safe upkeep of the vehicles via maintenance in the Orbiter Processing Facilities (OPFs).
'NASA has been tasked to study options regarding extension of the SSP (Space Shuttle Program) to support the ISS,' added Mr Shannon. 'The problem is that the Shuttle was never designed as a primary crew return vehicle. Soyuz-type vehicles are needed for this type of mission.
'The key item to keep in mind is that whatever is decided cannot impact the Constellation transition.'
For now, managers have requested that evaluations take place without being concerned about the budgetary pressures. The current outline refers to flying two orbiters, twice a year, to 2015.
Under evaluation will be challenges relating to the safe flight of the vehicles, notably based around the Orbiter Maintenance Down Period (OMDP) solutions installed into Atlantis' additional two years of flight.
The creation of 'mini-OMDPs' for Atlantis was approved to allow her to avoid retirement after STS-125. This involves prioritizing and carrying out required maintenance procedures in-between flights - avoiding the large downtime a full OMDP would normally require, and which is no longer viable based on the current 2010 retirement date.
Should these 'mini-OMDPs' prove to be an adequate solution to keeping two orbiters flying for an additional five years, the possibility of avoiding a 2010 end to the shuttle's flying days - pending budgetary issues - will be very much on the cards.
Regardless, at this stage, the process is just an assessment - the traditional back up plan NASA always has to hand.
Another article based on the full outline of the assessment will follow next week.
http://www.nasaspaceflight.com/content/?cid=5504
Wayne Hale è poco convinto:
Shutting down the shuttle
Posted on Aug 28, 2008 10:15:05 AM | Wayne Hale
I believe it was General Norman Schwartzkopf who said: "Arm chair generals study tactics; real generals study logistics".
One of the first lessons I learned in program and project management is that attention to the details of supplies, vendors, and parts manufacturers will determine success or failure more than anything else that management does. They are not glamorous, Hollywood does not make movies made about them, but logistics and supply chain are the unsung pillars on which every major project rests.
It is nice to have eloquent oratory and high flown philosophical statements, but the real way that real programs are really controlled is through the money. When the logistics and supply budget is stopped, the program is over. Momentum and warehoused supplies can carry on for a short period, but when those are exhausted, its time for the museum.
Starting four years ago, the shuttle program in its various projects made "lifetime buys". That is, we bought enough piece parts to fly all the flights on the manifest plus a prudent margin of reserves. Then we started sending out termination letters. About two years ago, we terminated 95% of the vendors for parts for the external tank project, for example. Smaller, but still significant, percentages of vendors for SSME, Orbiter, and RSRB have also been terminated.
A lot of things that go into the shuttle build up are specialty items. Electronics parts that nobody makes any more (1970's vintage stuff). Hey, if it works, why invest money in certifying new parts? Certifying new ones would be even more costly! Specialty alloys to meet the extraordinary demands of space flight, parts that are made by Mom and Pop shops mostly in the LA basin are norm rather than the exception. You might think that simple things like bolts and screws, wire, filters, and gaskets could be bought off the shelf some where, but that thinking would merely prove how little you know about the shuttle. The huge majority of supplies, consumable items, maintenance items, they are all specially made with unique and stringent processes and standards.
Our shuttle history tells us that when we try to cut corners, trouble results. Small, even apparently insignificant changes have caused big problems. For example, the unheralded end of production of a solvent caused enormous complications for the SRB folks a few years back when things started falling apart unexpectedly. It took a huge engineering detective effort to determine that small chemical changes in the new solvent were the culprit. Anything coming apart in the SRB is not good. There are hundreds of similar examples.
There is a long and arduous process to certify a vendor to produce the logistical parts for the shuttle. Not many companies do this work. Almost all of them are extraordinarily proud of the role they play in America's space program. A lot of them have been there from the beginnings in the middle 1970s. So when a Mom and Pop specialty shop gets a termination letter from the shuttle program after 35 years of production and they have other customers, guess what happens? Mom and Pop decide to close the shop, pension off their highly skilled workers, and then Mom and Pop move out of LA to their retirement cottage in the mountains or at the sea shore.
A lot of this has been happening over the last four years; most of it over two years ago.
So, just for the sake of argument, lets see what would happen if somehow we decided to fly the shuttle some more flights?
From time to time a vendor of specialty parts for the shuttle has gone out of business. Our experience then is that we have immense problems getting anybody to even bid on making replacement items. Sometimes, with hat in hand, we have to knock on doors. Always, we have to offer premium payments to get those exotic, small production run parts made.
Given time and money, anything is possible. But we are always short on time and money. Life seems to be like that.
To take one little example: if we started today to build another external tank at MAF, there are probably enough parts on the shelf. But very shortly we would exhaust supplies of some parts. Maybe on the second tank -- which we need to start in 3 months or so -- would have to get a new supply of specialty parts. Sometimes the old vendor is still there and could be persuaded to make more of the old parts. But in many cases, a new vendor would have to be found. Since the production run would be small, a premium price would have to be paid; and a certification effort requiring 6 to 12 months would start. Initial production likely would have a number of rejects as the workers learn the process. Hmm. In probably 15 to 18 months would would have the parts to build that second tank -- only a year or so later than we needed them. So a new gap would form. Not between shuttle and orion but between shuttle and shuttle.
And what would we get: even higher price per flight of an old technology which is not nearly as safe as we would like . . .
Hey, I am the biggest shuttle hugger there is. I think it is the best spacecraft ever built. But I also deal in the real world.
Where does the money come from? Where do the people -- who should be working on the moon rocket -- where do they come from?
We started shutting down the shuttle four years ago. That horse has left the barn.
In sostanza i contratti con molti fornitori, con l'avvicinarsi della fine del programma, sono già stati terminati.
Se si volesse continuare a far volare lo Shuttle bisognerebbe trovare qualcuno che produca queste parti (molto spesso cose particolari, che non produce più nessuno) o certificarne di nuove. In tutti e due i casi occorrerebbe investire molti $$$ in un programma in chiusura, con comunque un gap di almeno un anno a causa dei tempi necessari a produrre questi pezzi e assemblarli.
Fosse per me vedrei bene una collaborazione con l'ESA per uno sviluppo velocizzato di una versione "capsula" di ATV. Però non so quanto sia fattibile dal punto di vista tecnico e politico..
Wayne Hale è poco convinto:
In sostanza i contratti con molti fornitori, con l'avvicinarsi della fine del programma, sono già stati terminati.
Se si volesse continuare a far volare lo Shuttle bisognerebbe trovare qualcuno che produca queste parti (molto spesso cose particolari, che non produce più nessuno) o certificarne di nuove. In tutti e due i casi occorrerebbe investire molti $$$ in un programma in chiusura, con comunque un gap di almeno un anno a causa dei tempi necessari a produrre questi pezzi e assemblarli.
Ho letto..infatti trovo le notizie pubblicate quantomeno contrastanti :eek:
Quello che posso pensare e' che possano pianificare l'estensione del programma Shuttle nel caso i rapporti tra USA e Russia si degradino ulteriormente (a causa della guerra in Georgia, scudo spaziale, ecc.)
Fosse per me vedrei bene una collaborazione con l'ESA per uno sviluppo velocizzato di una versione "capsula" di ATV. Però non so quanto sia fattibile dal punto di vista tecnico e politico..
Sarei curioso anch'io di sapere se una simile soluzione sia praticabile..
Dal punto di vista del vettore l'Ariane dovrebbe essere in grado, poi mancano capsula e soprattutto la volonta' politica di realizzarla.
Gli americani comunque sembrano preoccupati della loro "impotenza", della loro impossibilita' per almeno 5 o 6 anni di far vedere che sono in grado di mandare qualcuno sullo spazio (quando ci riescono i Russi e i Cinesi)
AlexGatti
01-09-2008, 12:04
Ho letto..infatti trovo le notizie pubblicate quantomeno contrastanti :eek:
Quello che posso pensare e' che possano pianificare l'estensione del programma Shuttle nel caso i rapporti tra USA e Russia si degradino ulteriormente (a causa della guerra in Georgia, scudo spaziale, ecc.)
Mi sembra proprio buttare via i soldi l'estensione dello shuttle per 5 anni.
O si decide di certificare nuove parti (e costruire nuovi orbiter) per estendere la vita dello shuttle di altri 15 anni, oppure è meglio la soluzione proposta da Rand:
Originariamente inviato da Rand
Fosse per me vedrei bene una collaborazione con l'ESA per uno sviluppo velocizzato di una versione "capsula" di ATV. Però non so quanto sia fattibile dal punto di vista tecnico e politico..
Sarei curioso anch'io di sapere se una simile soluzione sia praticabile..
Dal punto di vista del vettore l'Ariane dovrebbe essere in grado, poi mancano capsula e soprattutto la volonta' politica di realizzarla.
Questa sarebbe una soluzione molto più intelligente, del resto se prima volevano comprare le soyuz dall'ex nemico giurato, la russia, non vedo cosa ci sia di male a comprare le ATV capsula da un alleato di ieri e di oggi quale l'europa. Ovviamente l'Esa dovrebbe premere l'acceleratore per certificare L'ATV ad uso umano, ma al mio occhio questo è molto più semplice che non estendere la vita degli shuttle.
Gli americani comunque sembrano preoccupati della loro "impotenza", della loro impossibilita' per almeno 5 o 6 anni di far vedere che sono in grado di mandare qualcuno sullo spazio (quando ci riescono i Russi e i Cinesi)
Direi che fanno bene ad esserne preoccupati, questa è la conseguenza della politica con cui hanno gestito la nasa, il cui culmine è stato quando bush da una parte parlava di piani per la luna e per marte e dall'altra tagliava i bilanci.
P.s.: Ma non si potrebbe indire una gara per chiunque (imprese private) fosse in grado di fornire un sistema per raggiungere la Iss?
Sto pensando che forse Burt Rutan ce la potrebbe fare di qui al 2011.
Ho letto..infatti trovo le notizie pubblicate quantomeno contrastanti :eek:
Quello che posso pensare e' che possano pianificare l'estensione del programma Shuttle nel caso i rapporti tra USA e Russia si degradino ulteriormente (a causa della guerra in Georgia, scudo spaziale, ecc.)
Il motivo è certamente quello, il problema è capire la soluzione migliore..
Sarei curioso anch'io di sapere se una simile soluzione sia praticabile..
Dal punto di vista del vettore l'Ariane dovrebbe essere in grado, poi mancano capsula e soprattutto la volonta' politica di realizzarla.
Per la LEO Ariane 5 è quasi certamente sufficiente, dovrebbe anche essere "facile" da certificare per il volo umano visto che era uno dei requisiti originali. La capsula non saprei quanto possa essere lunga da sviluppare.. In ogni caso prima bisognerebbe appunto superare gli scogli politici.
Per eventuali future missioni Lunari si parla di 2 o 3 lanci di una versione da 50 tonnellate di Ariane 5, in congiunzione con una ministazione in orbita polare intorno alla Luna. Questa minibase avrebbe come vantaggio quello di far comodo anche al programma USA (ad esempio in caso di malfunzionamenti gravi, gli astronauti potrebbero sfruttarla per salvarsi le :ciapet:).
Gli americani comunque sembrano preoccupati della loro "impotenza", della loro impossibilita' per almeno 5 o 6 anni di far vedere che sono in grado di mandare qualcuno sullo spazio (quando ci riescono i Russi e i Cinesi)
Giustamente.. adesso che hanno praticamente finito la ISS sarebbe bello essere sicuri di poterci arrivare :D
Mi sembra proprio buttare via i soldi l'estensione dello shuttle per 5 anni.
O si decide di certificare nuove parti (e costruire nuovi orbiter) per estendere la vita dello shuttle di altri 15 anni, oppure è meglio la soluzione proposta da Rand:
Questo significherebbe sostenere 2 programmi in parallelo (Constellation e Shuttle 2.0). Costa troppi $$$
P.s.: Ma non si potrebbe indire una gara per chiunque (imprese private) fosse in grado di fornire un sistema per raggiungere la Iss?
Sto pensando che forse Burt Rutan ce la potrebbe fare di qui al 2011.
Negli USA c'è già (se non ricordo male l'iniziativa si chiama COTS), solo che per adesso non si vedono risultati, specie per quanto riguarda il trasporto umano..
Per Burt Rutan la vedo dura visto che dovrebbe sviluppare un mezzo orbitale, con requisiti in termini di velocità da raggiungere e di conseguenza energia da dissipare al rientro molto più gravosi: la SpaceShipTwo fa 4,200 km/h, per andare in orbita ne occorrono circa 25,000 km/h.
AlexGatti
01-09-2008, 13:19
Per la LEO Ariane 5 è quasi certamente sufficiente, dovrebbe anche essere "facile" da certificare per il volo umano visto che era uno dei requisiti originali. La capsula non saprei quanto possa essere lunga da sviluppare.. In ogni caso prima bisognerebbe appunto superare gli scogli politici.
Mi sembra la via migliore di gestire la cosa.
Questo significherebbe sostenere 2 programmi in parallelo (Constellation e Shuttle 2.0). Costa troppi $$$
Se:
- non possono usare le soyuz
- non vogliono venire a patti con l'ESA
- non vogliono essere esclusi dalla ISS
Direi che questa è l'unica alternativa sensata.
Per Burt Rutan la vedo dura visto che dovrebbe sviluppare un mezzo orbitale, con requisiti in termini di velocità da raggiungere e di conseguenza energia da dissipare al rientro molto più gravosi: la SpaceShipTwo fa 4,200 km/h, per andare in orbita ne occorrono circa 25,000 km/h.
Peccato
Tornando al presente degli Shuttles, l'Atlantis e' ora al Pad 39A pronto per la missione STS-125 di manutenzione/upgrade al telescopio spaziale Hubble.
http://www.spaceflightnow.com/shuttle/sts125/images/sts125sidebar.gif
immagine presa da Spaceflightnow
l'Endeavour verra' tra pochi giorni portato al pad "gemello" 39B per l'eventuale missione di soccorso LON-400
In attesa della consueta apertura del thread dedicato da parte di GioFX metto un po' di links utili:
http://spaceflightnow.com/shuttle/sts125/status.html
http://spaceflightnow.com/shuttle/sts125/fdf/125flightplan.html
http://www.nasaspaceflight.com/content/cat.asp?cid=5
http://www.nasa.gov/mission_pages/hubble/servicing/SM4/main/index.html
Per STS-125 si possono trovare alcune belle foto qui (http://www.boston.com/bigpicture/2008/09/preparing_to_rescue_hubble.html)..
http://cache.boston.com/universal/site_graphics/blogs/bigpicture/shuttle_09_01/sts125_1.jpg
http://cache.boston.com/universal/site_graphics/blogs/bigpicture/shuttle_09_01/sts125_10.jpg
http://cache.boston.com/universal/site_graphics/blogs/bigpicture/shuttle_09_01/sts125_11.jpg
In Leaked Email, NASA Chief Vents On Shuttle Program's End
"In a leaked memo, NASA Administrator Mike Griffin discusses 'the jihad' to prematurely terminate the Shuttle and what that means for the International Space Station. One implication: there may come a long interval when only our Russian Allies are aboard the Space Station. Add that bit of irony to your new cold war kit and then wonder why Griffin discusses why we wouldn't sabotage the Space Station, and how and why the memo got leaked in the first place."
Fonte 1: Link (http://science.slashdot.org/article.pl?sid=08/09/08/0421222&from=rss)
Fonte 2: Link (http://www.space.com/news/080907-nasa-griffin-email.html)
danny2005
09-09-2008, 09:00
Caruccia l'astronauta americana :flower:
La notizia e' di qualche giorno fa ma merita comunque un po' di attenzione:
http://www.nasaspaceflight.com/Images/Thumbnails/Thumbnailer.ashx?Img=library/1016/A1(246).JPG&W=226&H=168
NASA's dream scenario of a 13 flight extension for shuttle
By Chris Bergin, 9/17/2008 4:13:07 AM
From a hardware standpoint, the space shuttle fleet could technically fly until 2015, involving up to 13 extra flights - that's the result of the opening findings from the on-going extension assessment.
Several options - all based around flying two orbiters past 2010, with the support of an ISS "lifeboat" - have been created, although the forward plan of extending the Iran/North Korea/Syria Agreement (INKSA) waiver to utilize the Russian Soyuz remains the favored approach.
E qui leggete il resto dell'articolo:
http://www.nasaspaceflight.com/content/?cid=5516
Prosegue (http://www.nasaspaceflight.com/2008/10/rcc-panel-tiger-team-update/) il lavoro per comprendere a pieno alcuni fenomeni di degradazione del rivestimento protettivo dei pannelli in RCC dello Shuttle:
Another status update has been issued by the NASA Tiger Team which is investigating the cause of a potential problem with the orbiter’s Reinforced Carbon-Carbon (RCC) leading edge panels.
About a year ago this group was established to determine the circumstances behind an issue where the RCC’s Silicon Carbide (SiC) coating can flake away, and to find out what methods should be used to test the panels and how to go about getting replacement panels for future missions.
The focus of this team is based upon concern about a loss of critical SiC coating, which could result in the loss of crew and vehicle. To reduce the risk, the Space Shuttle Program (SSP) inspects, removes and replaces panels with a line scan magnitude (Wf) of 0.2. That criteria has resulted in 10 panels being removed from the fleet.
Six new panels have been procured to maintain a spare inventory of at least one panel per location. Three have been ordered, the first of which (10R) is expected to be delivered in December. A mid-summer progress report detailed tests that had been completed along with early results while the investigation continues ahead of a Technical Interchange Meeting (TIM) scheduled for October 28-30.
Fifteen of 21 scheduled tests have been completed at this point, with five more in progress and one additional (Hot Gas Testing) still in the planning stage. The fracture mechanics summary has shown that on-orbit cold soak will not propagate any existing defects, but it’s possible that forces from re-entry could exceed the capability of the RCC coating. Three-dimensional fracture analysis is in work to reduce the conservative nature of that test.
Some of the arc jet testing has resulted in major changes in panels’ Wf values. Two samples of panel 10L have show dramatically different behaviors than other test samples and flight history, with one climbing from a Wf of 0.3 to as high as 1.3.
Changes in temperatures from a so-called “Stress Free Temperature” have been shown to cause stress on the panels. At this SFT (usually around 1350 degrees F, but can range from 700-1700 degrees F) the craze crack surfaces are just touching. There are no stresses in the SiC coating or at the SiC/C-C interface.
If the temperature is below the SFT (for example, during on-orbit cold soak) then cracks can open because the SiC contracts at a faster rate than the C-C, generating stress in the interface - a mode II fracture. If the temperature is higher than the SFT (during re-entry or panel refurbishment) the SiC expands at a higher rate than the C-C, so the islands are forced together and upward - mode I.
The fault tree for a root cause mechanism has been about 40 percent completed. The hypothesis is related to the local curvature along the joggle, with indications that stress induced from re-entry temperatures may exceed the material strength. Damage at or near the SiC/CC interface has been observed to grow during arc-jet and thermal tests.
Variations in the material could explain why damages are not more widespread, and subsurface damage near the interface is a significant contributing factor to the coating falling off (spallation.) However at this point, the exact mechanism leading to spallation, or the conditions under which it can occur, have not been identified.
The thermal loads of re-entry do not appear to be sufficient to cause spallation based on arc-jet conclusions, so questions remain if vibration and pressure loads are enough to spall the coating.
An additional 190 re-entry cycles are to be simulated in arc-jet testing, with a statistical evaluation of data to determine the safe-to-fly limit. Analysis of defect flight history and test data will help provide confidence in the expected growth rates of defects. Global stress assessment sensitivity cases are also to be completed.
Microscopy of flown and unflown joggles will continue, in order to support closing additional fault tree blocks. It may help explain the cause of reduced material strength by looking at the coating thickness, porosity of the material, or other parameters.
The stress free temperature (SFT) needs to be refined, and 2D/3D fracture mechanics need to be understood. The 3D models will reduce conservatism of the current 2D analysis. The refurbishment fault tree block is hoped to be closed with arc-jet and multi-parameter tests of refurbished joggles.
RCC joggle testing at Sandia National Lab using acoustic and infrared techniques should improve the understanding of when joggle damage initiates or grows, which would help determine the criticality of damage or spallation.
Three existing data points show damage occurs at peak heating (IR data analysis, arc-jet thermal response, and “off-gassing” during arc jet tests.) If SiC falls off during re-entry, the Carbon-Carbon is exposed for less than a full re-entry thermal cycle, so the time and location will dictate the extent of oxidation and/or burn-through time.
The arc jet needs to be tested to see if the environment matches the actual state from entry interface to 1100 seconds. If it is not representative, then wind tunnel testing of test coupons might be necessary at Ames Research Center or Texas A&M to simulate pressure loads.
It is estimated that the ascent vibration is an order of magnitude greater than re-entry, but that needs to be formally assessed. A determination then can be made of how many equivalent re-entry vibration cycles panel 16R has been exposed to during testing. They may then need to clean that panel and re-vibe it with an existing 0.46 Wf defect.
Analysis will be performed to determine local pressure effects on a degraded piece of joggle SiC, as aerodynamic loads may be sufficient to spall a chip during re-entry. Along the same lines, hot gas testing of a panel with a large defect (over 1.3 Wf) might help determine what loads are necessary to induce spallation.
Arc jet cycles will continue on specimens until spallation occurs, and other pieces will be vibration tested until SiC spallation.
Much progress has been made in understanding the mechanism for SiC damage initiation and growth. The current focus is on the timing and cause for SiC spallation. At the TIM (Technical Interchange Meeting) later this month, the team will review data, refine a forward plan for root cause investigation, and discuss raising the 0.2 Wf “go/no-go” limit for RCC panels.
All testing and analysis is expected to be completed by mid-December, with peer review scheduled for the late February/early March 2009 timeframe.
Wayne Hale parla (http://blogs.nasa.gov/cm/blog/waynehalesblog.blog/posts/post_1224882373544.html) delle procedure che prevedono di far autodistruggere lo Shuttle se va fuori controllo e diventa una minaccia per la popolazione civile:
Deputy of the Range
Each time I sat at the Flight Director console during a shuttle countdown, about three hours before launch time, they brought me a plain white envelope, sealed.
The envelope contained exactly one sheet of plain white paper with less than a dozen words typed in crisp black font.
On that paper were the Code Words.
A few minutes later, an unfamiliar voice would call over the Flight Director’s communication loop: “Flight, this is FCO. How do you read?” My response as prescribed by this particular ritual was always: “Loud and Clear. How me?” And like clockwork, the unfamiliar voice would say: “Loud and Clear”. We always followed that up with some very stilted pleasantries: How are you today? Fine. And you?
And then, having established that voice communications were working properly, the unfamiliar voice would go away. And I would fervently wish not to hear it again that day.
FCO, the Flight Control Officer, is a military officer whose duty station is in the Range Operations Control Center – the ROCC, pronounced “rock” – a dozen miles south of the shuttle launch pads. The President of the United States had delegated the authority and responsibility of the protection of the civilian population of the state of Florida from errant space vehicles to the FCO. All launch vehicles are required to have a "flight termination system" installed which the FCO will utilize to protect the public. This requirement includes, of course, the space shuttle.
By long standing jointly signed Flight Rules, if the shuttle were to veer off course, spin out of control, or break up, my responsibility as Shuttle Ascent Flight Director was to transmit those Code Words on my loop. On hearing those words, the FCO would depress the two buttons in front of him to – as we say – ‘terminate the flight’. That means exactly what you think it means. I don't have to spell it out.
It goes without saying that I never wanted to say those words.
Not that it would likely matter. The FCO has radar trackers, optical sites, observer reports. The FCO would have probably already "Sent Functions" before I would be able to call him. Small comfort, that.
When you go to the ROCC and get the range safety briefing from the FCO, they show you a video of an early Chinese Long March rocket that suffered a boost phase failure. Flaming chunks of rocket streamed down on an unsuspecting village, killing dozens and wounding hundreds. Just a few miles from the shuttle launch pads are the large and growing Florida communities of Titusville, Cape Canaveral, Cocoa Beach, Melbourne, Rockledge, Cocoa, and more. Not far north lays Daytona Beach. And the shuttle launch trajectory does not go far from the outer banks of North Carolina, New England, Newfoundland. There are a lot of people that might need protection.
After a very social evening filled with many vodka toasts, a Russian colleague of ours asked the very pertinent question: “Why would you put a range safety destruct package on a manned spacecraft?”
That question was the reason the FCOs always showed the video of the Chinese village. The FCOs shows the same video to the astronauts, too.
You see, the shuttle Commander and Pilot are designated Agents or Deputies of the Range. The destruct package is built into the Solid Rocket Boosters and those are jettisoned two minutes into an eight and a half minute powered flight. After that, should the shuttle go off course toward a populated area, the FCO can do nothing about it. The responsibility which the President of the United States has given to the FCO cannot be accomplished – except to call the crew and tell them to do what is necessary.
So we practice these scenarios – far fetched as they may be – to ensure that the crew knows what to do. Steer out to sea; shut down the main engines, protect the population along the eastern seaboard. One small problem – that procedure puts the shuttle crew into what is delicately labeled a “black zone”. If the shuttle is high enough – as it is for much of the boost phase – but with forward velocity significantly below orbital speed – then an unpowered entry will result in the g-loads and heating which builds up too fast, faster than the wings can generate lift. And the result? Well.
So the Commander and the Pilot are designated Deputies of the Range. If the really bad thing happens, they are sworn to protect the population of the east coast, even at the expense of their crews’ lives.
It takes courage to fly in space.
Un fornitore della NASA rischia (http://www.myfoxhouston.com/myfox/pages/News/Detail?contentId=7860546&version=2&locale=EN-US&layoutCode=TSTY&pageId=3.2.1) fino a 15 anni di prigione e 500000 dollari di multa per aver consegnato un "pezzo" che non rispettava le specifiche e aver cercato di nasconderlo:
Alvin Man Indicted on Allegations He Gave NASA Faulty Shuttle Part
HOUSTON -- As Space Shuttle Endeavour gets ready to launch Friday night, a NASA contractor is facing a 2-count federal indictment involving shuttle parts.
A federal grand jury indicted 60-year-old Richard Harmon, owner of Cornerstone Machining, Inc. in Alvin. He is charged with fraud and making a false statement.
Before Endeavor launched in March 2008, a damaged part was discovered in the shuttle's payload bay. The damage reduced the structural strength of the part by approximately 40 percent. The indictment alleges the part was damaged during construction and Harmon attempted to fix it with a weld, but didn't tell anyone.
"There's no allegation he built the part poorly, he did not build the part to specifications and he tried to cover that up," said acting U.S Attorney Tim Johnson.
According to the indictment, "If NASA had used the damaged PFIP as planned to secure cargo to the Endeavour the weld could have cracked open during flight, allowed cargo to come loose and possibly result in the loss of the spacecraft."
If convicted Harmom faces a maximum of 15 years in prison and a $500,000 fine.
Attempts by Fox 26 to reach Harmon were unsuccessful. NASA refused to comment.
in base a quanto riportato il componente, utilizzato per assicurare il payload all'interno dello Shuttle, si era danneggiato durante la lavorazione ed è stato riparato con una saldatura.
Se non fosse stato scoperto e sostituito avrebbe potuto rompersi durante il lancio liberando il carico, portando alla perdita dello Shuttle (e del suo equipaggio).
Altre belle foto (http://www.boston.com/bigpicture/2008/12/round_trip_with_endeavour.html) da The Big Picture:
http://cache.boston.com/universal/site_graphics/blogs/bigpicture/roundtrip_12_22/26_17372687.jpg
http://cache.boston.com/universal/site_graphics/blogs/bigpicture/roundtrip_12_22/08_08pd2615.jpg
Nel sito ho trovato anche la foto del recupero booster, pensavo fossero quasi distrutti e invece si sono tenuti, ma come fanno con un impatto così alto?!
Nel sito ho trovato anche la foto del recupero booster, pensavo fossero quasi distrutti e invece si sono tenuti, ma come fanno con un impatto così alto?!
Vengono sganciati relativamente presto (dopo circa 2 minuti dal lancio), quindi vanno abbastanza piano da non subire un riscaldamento eccessivo. Poi quando arrivano ad una certa altezza si apre il paracadute che rallenta la caduta nell'oceano in modo che non subiscano danni "eccessivi" e dopo un opportuna manutenzione/sostituzione di alcuni pezzi possano essere riutilizzati.
Contribuisce il fatto che essendo a combustibile solido sono semplici (niente motori complessi e fragili) e che sono realizzati in acciaio (essendo sganciati presto il loro peso è relativamente poco influente sul carico totale che può essere portato in orbita).
Qui (http://it.youtube.com/watch?v=FVUcW-4C18U) si può vedere un bel video dal lancio all'ammaraggio.
Vengono sganciati relativamente presto (dopo circa 2 minuti dal lancio), quindi vanno abbastanza piano da non subire un riscaldamento eccessivo. Poi quando arrivano ad una certa altezza si apre il paracadute che rallenta la caduta nell'oceano in modo che non subiscano danni "eccessivi" e dopo un opportuna manutenzione/sostituzione di alcuni pezzi possano essere riutilizzati.
Contribuisce il fatto che essendo a combustibile solido sono semplici (niente motori complessi e fragili) e che sono realizzati in acciaio (essendo sganciati presto il loro peso è relativamente poco influente sul carico totale che può essere portato in orbita).
Qui (http://it.youtube.com/watch?v=FVUcW-4C18U) si può vedere un bel video dal lancio all'ammaraggio.
:ave:
Rilasciato un ultimo report (http://www.nasa.gov/pdf/298870main_SP-2008-565.pdf) sull'incidente del Columbia:
NASA commissioned the Columbia Accident Investigation Board (CAIB) to conduct a thorough review of both the technical and the organizational causes of the loss of the Space Shuttle Columbia and her crew on February 1, 2003. The accident investigation that followed determined that a large piece of insulating foam from Columbia’s external tank (ET) had come off during ascent and struck the leading edge of the left wing, causing critical damage. The damage was undetected during the mission. The CAIB’s findings and recommendations were published in 2003 and are available on the web at http://caib.nasa.gov/. NASA responded to the CAIB findings and recommendations with the Space Shuttle Return to Flight Implementation Plan. Significant enhancements were made to NASA’s organizational structure, technical rigor, and understanding of the flight environment. The ET was redesigned to reduce foam shedding and eliminate critical debris. In 2005, NASA succeeded in returning the space shuttle to flight. In 2010, the space shuttle will complete its mission of assembling the International Space Station and will be retired to make way for the next generation of human space flight vehicles: the Constellation Program.
The Space Shuttle Program recognized the importance of capturing the lessons learned from the loss of Columbia and her crew to benefit future human exploration, particularly future vehicle design. The program commissioned the Spacecraft Crew Survival Integrated Investigation Team (SCSIIT). The SCSIIT was asked to perform a comprehensive analysis of the accident, focusing on factors and events affecting crew survival, and to develop recommendations for improving crew survival for all future human space flight vehicles. To do this, the SCSIIT investigated all elements of crew survival, including the design features, equipment, training, and procedures intended to protect the crew. This report documents the SCSIIT findings, conclusions, and recommendations.
Wayne Hale ha riproposto un intervento che aveva scritto nel 2004. Lettura consigliata:
Tomorrow marks the 5th anniversary of a fundamental change in national direction for space exploration. You can look up that text at
http://www.whitehouse.gov/news/releases/2004/01/20040114-3.html
This came at an interesting time in my life. Reflecting on that direction and the other turbulent events of those days, I wrote an email to my space shuttle team members as I often did in those days. Looking back, I think it was one of the best things I ever wrote. I have re-read it and still agree with every single sentence. I hope you won't mind if I recycle this essay for your consideration on this anniversary:
From: HALE, N. W., JR (WAYNE) (JSC-MA) (NASA)
Sent: Tuesday, January 27, 2004 5:25 PM
Subject: Adjusting Our Thinking
To the Space Shuttle Team:
I have been doing a lot of thinking lately: the approaching anniversary of the Columbia accident, reading the new book on the accident, the incessant questions from the press, the opportunity to observer our JPL colleagues in their time of testing, and most importantly thinking about the new policy and direction from our leaders. Like many of you I have had some mixed emotions from all of this. I would like to share some of my thoughts with you.
The vision of future space exploration existed long before we came to work here. It is a natural continuation of the American dream. The vision has shown up over the years in dozens of NASA strategic planning documents, reports from special commissions, and the like. I signed onto the vision as a schoolboy, long before I came to work here. Many of you did the same. The vision has variations in detail and timetable, but the central theme has not varied for decades. Explore the solar system; first by sending robots and then with people establishing outposts, then base camps, and eventually colonies.
In my mind's eye our progress is like the Olympic torch relay: each person and each program holds the flame of exploration and progress high for an allotted portion of the route, and then the torch is passed to the next runner in the relay. Sometimes we run alone and sometimes we run together with others, but the goal is to move the flame forward, to illuminate the darkness, to allow the next generation to start just a little closer to the goal. The goal of exploring and settling the solar system will not be completed in our lifetime or our children's lifetime. But we - here and now - are called to run our lap with skill, dedication, vigilance, hard work, and pride.
It sometimes seems that there is never enough commitment or enough money to accelerate the vision into fast forward. The march to the future moves with fits and starts. Sometimes we have had to compromise for what we could get, accept the part of the dream could be sold at any given time. This is what happens in so much of real life: doing the best we can with what we have. In spite of this, this generation has done great things in low earth orbit and our colleges have made tremendous strides exploring ahead of us with robots.
The steady grind and necessary constant attention to the daily tasks has shifted our gaze from the higher vision. We have become accustomed to putting the vision off, waiting for the day - long to come - when we could take the next step into the cosmos. Every year we have tried to be more efficient than the year before in the hopes that we could sock away enough money to build the future, to prove to our national leaders that we were fit to be given the permission to take the next bold step. Our attention shifted from the vision to the next flight. We came to accept the status quo as the best that could be. We became complacent in more than our technical abilities. We became complacent about the vision. It became enough for us to do great things in low earth orbit. And in that day to day grind our hearts have come to believe the vision is something far off, something for the distant future.
The shuttle is a marvelous and revolutionary machine. You, the people that make her fly, are incredible in your dedication and attention to detail. The achievements that the shuttle has produced will be heralded in the history books of future years. A short list hardly covers all the shuttle's achievements: first and only reusable spacecraft, heavy lift launch vehicle, heavy cargo return vehicle, delivering three times more people to orbit than all other space vehicles to date combined, the most successful launch vehicle in the world, the most efficient engines ever made; the list could go on for many pages. Don't believe the critics when they sell her short.
But those of us who know her best know her shortcomings. She is terribly complex; she is extraordinarily difficult to prepare for flight, she is too expensive to operate, and frankly, she is not as safe as we need our human transport vehicle to be.
The shuttle is an amazing machine, but like every other machine ever built, she is the result of a series of compromises, built within financial constraints, a product of the state of the art of technology when she was designed.
So too will be the next space vehicle we build.
The shuttle was supposed to be the DC-3 of space travel; the DC-3 became the first economically successful airliner; safer than anything flying at the time - not perfect, but just what was needed to cause air travel to become commonplace. Yet the analogy falls apart when we remember that in the 31 years between the Wright flier and the DC-3 ten thousand different aircraft types were designed and build. Designs and technologies were tried, tested, evaluated, and either discarded or incorporated into future, better aircraft. In the 42 years of human space flight, there have been exactly 9 different model spacecraft built by all the nations of the world. Without similar experience of trial and evaluation building multiple space vehicles, the wonder is that we came so close, not that we fell short. The real truth is, the shuttle does her job too well. She has never been quite bad enough to motivate the nation to build the next and better spacecraft. If the shuttle was not the DC-3 of the space age, the fact remains that the shuttle remains a huge advance in capability, technology, and even safety over all other spacecraft.
We cannot let the familiarity of long years and the investment of our personal time and energy in any one program or any one vehicle confuse that program or that vehicle with the vision. The shuttle has its place and time in the great relay but it is not an end in itself. Those of us in the shuttle program need to take care lest we become the battleship admirals of the new century; failing to understand when times have changed and in which direction progress is marching toward. We must move out of what is comfortable and familiar.
It is time to adjust our thinking.
In a virtual reality age, spaceflight is profoundly real. Surrounded by imitations of real life on computers, at the movies, on television, our work has real consequences. Every time we light the SRBs, the stakes are high. First of all the lives of the crew are on the line. Next, a great investment of our nation's treasure in the form of the vehicle itself and the facilities that support and surround it are at risk. They are at real risk, not theoretical or philosophical or virtual risk, but risk of life and limb and physical destruction. There is more. You must understand that every time the countdown clock reaches T=0, we bet the future, and we do it with the whole world watching. Not only are we wagering the program; we lay the agency on the line. Not only is the agency at risk, but national pride and esteem are in question. Not only national pride is at stake, but we place the human exploration of the cosmos for a generation on the table. Until the wheels safely kiss the runway, everything is in play. I don't know any other agency or any other organization where that is so completely and thoroughly true. With all of that at stake, the very best of our abilities and efforts is required.
When we build the new human space launch vehicle and count the clock down to T=0, we will make same gamble. It is the only way to get to the universe; bet everything on every single step forward.
Last year we dropped the torch through our complacency, our arrogance, self-assurance, shear stupidity, and through continuing attempt to please everyone. Seven of our friends and colleagues paid the ultimate price for our failure.
Yet, the nation is giving us another chance. Not just to fly the shuttle again, but to continue to explore the universe in our generation. A year ago it was my firm belief that a second fatal accident in the shuttle program would result in the lights being turned out at NASA, the vision would go into hiatus for a generation, and we - all of us in the agency - would be through. Instead, the nation has told us to get up, fix our shortcomings, fly again - and make sure it doesn't happen again. That is the goal to which we are all working now.
No matter how hard we worked before, now is time to redouble our efforts. The vision runs right through the next launch of the shuttle. We cannot be found wanting again. The future steps depend on flying the shuttle safely and building the space station. These accomplishments are the necessary requirement to go on to the future.
Now we have been asked to raise our eyes to the bigger vision again. We are asked to look at what and who will run the next leg of the relay. Our lap may come to an end sooner that we had come to believe but the distance we have yet to run ahead is longer than it rightfully should be for those who have dropped the torch. We must not fail. It will demand constant attention in the face of many many many distractions, doubts, and critics. The task ahead is not easy. But then, it never has been easy. We just understand better what is required.
Therefore, do not worry about the future. We have work to do today. If we do it well, there will be even more work for us to do in the very near future. The foundation for that work is to fly the shuttle safely. We have been given a great mandate. Those of us who are in the shuttle program now will be required to help the next generation succeed. Write down what you have learned; pass it on to those who are starting to consider future designs. Many of you will be called on to lead that effort. Eventually, all of us will be called. But until then, stay focused on the task at hand. We must make sure that the next launch - and landing - and those that follow are safe and successful. That will be our finest contribution to the future, carrying the torch ahead.
P. S. A final, personal note: a worker at KSC told me that they haven't heard any NASA managers admit to being at fault for the loss of Columbia. I cannot speak for others but let me set my record straight: I am at fault. If you need a scapegoat, start with me. I had the opportunity and the information and I failed to make use of it. I don't know what an inquest or a court of law would say, but I stand condemned in the court of my own conscience to be guilty of not preventing the Columbia disaster. We could discuss the particulars: inattention, incompetence, distraction, lack of conviction, lack of understanding, a lack of backbone, laziness. The bottom line is that I failed to understand what I was being told; I failed to stand up and be counted. Therefore look no further; I am guilty of allowing Columbia to crash.
As you consider continuing in this program, or any other high risk program, weigh the cost. You, too, could be convicted in the court of your conscience if you are ever party to cutting corners, believing something life and death is not your responsibility, or simply not paying attention. The penalty is heavy; you can never completely repay it.
Do good work. Pay attention. Question everything. Be thorough. Don't end up with regrets.
Si fa più probabile il lancio (http://www.forumastronautico.it/index.php?topic=9857.0) di AMS (http://en.wikipedia.org/wiki/Alpha_Magnetic_Spectrometer) sulla ISS, che dopo l'incidente del Columbia era seriamente in dubbio (non c'era nessun volo dello Shuttle assegnato al suo trasporto):
E' probabilmente un altro passo verso la sua ufficializzazione ma dall'ultima review del programma di lanci della ISS per i prossimi due anni è comparsa questa volta come volo reale e non più come "possibile" la missione STS-134 per il trasporto sulla ISS, come payload principale, di AMS (Alpha Magnetic Spectrometer), l'importante strumento per la ricerca nei campi della fisica e dell'astrofisica di base e che vede la collaborazione per la realizzazione di diversi Paesi sparsi in tutto il mondo (per un totale di circa 1.5 miliardi di dollari di costo) e tra cui l'Italia partecipa fra i principali finanziatori.
Con l'inserimento della missione all'interno del calendario dei lanci sono stati ovviamente definiti anche la data di lancio, che per ora è fissata al 16 Settembre 2010 e la navetta, il Discovery.
Un'altro motivo di interesse per l'Italia oltre alla strumentazione scientifica di AMS è la possibile partecipazione alla missione di Roberto Vittori, già al JSC per l'addestramento al suo primo volo shuttle (dopo i due a bordo della Soyuz) e in fase di assegnazione ad una delle missioni del 2010 (STS-130 esclusa per equipaggio già nominato).
Sempre per l'inserimento della missione STS-134 in calendario è in fase di rivalutazione la distribuzione dei ricambi (ORU) fra le quattro missioni ora disponibili visto che il trasporto di AMS lascerà molto spazio e peso disponibile per altro materiale nella propria missione, con le tre missioni precedenti, STS-131, STS-132 e STS-133, che saranno completamente dedicate al trasporto di ricambi e materiale di scorta (fra questi probabilmente anche il nuovo anello del SARJ che non verrà installato ma solamente trasportato sulla ISS per esigenze eventuali future).
Dopo la missione STS-134 che attualmente rimane l'ultima del programma Shuttle regna ancora l'incertezza, ma da alcune notizie trapelate dagli stabilimenti NASA, e in particolare al MAF, dove vengono costruiti e assemblati i serbatoi esterni della navetta sembra possibile un prolungamento delle attività in orbita della navetta (al costo di circa 3 miliardi di dollari all'anno) con la costruzione degli ET-140 (STS-135) e ET-141 (STS-136) approvata e iniziata da pochi giorni con inoltre, i lavori di ripristino del serbatoio STS-122, danneggiato dall'uragano Katrina, precedentemente abbandonato e ora in fase di reimmissione in linea che proseguono e consistono ora nella rimozione della schiuma originale per riportarlo agli standard attuali di volo.
http://upload.wikimedia.org/wikipedia/en/0/0c/Alpha_Magnetic_Spectrometer.jpg
Si parla inoltre di un estensione dei voli Shuttle fino al 2012, anche se per ora non c'è niente di ufficiale (a giudicare dalle voci "nell'ambiente" sembra abbastanza probabile).
So che è un post vecchio, ma siccome è un opinione abbastanza comune è meglio fare un po' di chiarezza (imho :D)..
continuo a pensare che non sarebbe stata poi una cattiva idea continuare il progetto X33 (ormai ad uno stadio avanzato?) per le orbite LEO e sviluppare con piu' calma un vettore per le destinazioni piu' lontane.
Forse la mia e' solo nostalgia..
A breve-medio termine non sarebbe il modo migliore di procedere:
- X-33 era un dimostratore tecnologico per Venturestar: essendo suborbitale e con payload nullo come mezzo "in se" è inutile. Venturestar sarebbe un progetto da circa 15 miliardi di dollari da sviluppare praticamente da zero.
- Un SSTO riusabile con le tecnologie attuali è molto difficile da realizzare, per avere le dimensioni della sfida:
http://upload.wikimedia.org/wikipedia/commons/thumb/0/01/STS120LaunchHiRes.jpg/391px-STS120LaunchHiRes.jpg
bisogna mettere tutto nel veicolo mantenendo un payload decente. Per avere un buon margine o si migliora l'efficienza dei motori (quelli chimici sono già al limite, servono motori nucleari (http://en.wikipedia.org/wiki/Nuclear_thermal_rocket) o l'equivalente a fusione) o servono materiali estremamente leggeri.
- Per diventare conveniente rispetto a un veicolo "usa e getta" serve un elevato numero di voli all'anno (si parla di 25 circa). Ad oggi non esiste un mercato (o budget pubblici sufficienti) per un numero cosi' elevato di lanci.
Interessante post, Rand... un sistema tipo X-33 o cmq limitato al LEO, per durare almeno 20 anni, sarebbe improponibile in questo momento.
Bella questa immagine, che mette in scala i due veicoli attualmente più usati:
http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Space_Shuttle_vs_Soyuz_TM_-_to_scale_drawing.png/679px-Space_Shuttle_vs_Soyuz_TM_-_to_scale_drawing.png
Interessante post, Rand... un sistema tipo X-33 o cmq limitato al LEO, per durare almeno 20 anni, sarebbe improponibile in questo momento.
Se a breve-medio termine si volesse comunque un veicolo completamente riusabile imho* la strada da seguire è un TSTO (twin-stage to orbit). Per capirci una cosa cosi':
http://img101.imageshack.us/img101/4843/gfgfddgfvy1.jpg
* ovvero secondo le mie limitatissime conoscenze :D
Il lancio di STS-119 è stato rimandato in seguito a dei problemi con una valvola, che la NASA vuole capire nel dettaglio prima di procedere al lancio. Su nasaspaceflight.com c'è una (http://www.nasaspaceflight.com/2009/02/agency-frr-change-net-for-sts-119/) serie (http://www.nasaspaceflight.com/2009/02/understanding-the-threats-fcv-flight-rationale/) di (http://www.nasaspaceflight.com/2009/02/sts-119-net-february-22-risk-of-a-two-month-delay/) articoli (http://www.nasaspaceflight.com/2009/02/sts-119-net-february-22-risk-of-a-two-month-delay/) che spiegano nel dettaglio l'evoluzione della vicenda:
STS-119: Major NASA effort working through FCV testing and flight rationale
February 10th, 2009 by Chris Bergin
STS-119’s latest NET (No Earlier Than) launch target of February 22 remains the target, as engineers work through the Flow Control Valve (FCV) issue with the goal of approving flight rationale. Testing and documentation are being ramped up ahead of Friday’s special PRCB (Program Requirements Control Board) meeting.
Processing at Pad 39A is now holding for the outcome of the latest meetings, which will hopefully lead to a Delta Flight Readiness Review (FRR) on February 18. That in turn will decide whether to proceed towards the latest refined launch target of February 22.
“Sent out note last week announcing the schedule for STS-119 - PRCB this week on February 13; targeting an FRR next week on February 18; and launch NET February 22, obviously pending success as we go along,” noted information on L2. “When it firms up, we will send out an official letter with the actual dates and times.
“(Shuttle manager) John Shannon added that would be a Special PRCB on Friday just to talk Flow Control Valves (FCVs). Will have the normally scheduled PRCB on Thursday to do org clean-up items that we need to get to before flight.”
With the 22nd used as a planning date, processing flow realignments have set the preparations for the additional loading of Discovery’s Forward Reaction Control System tanks - called for the reboost the orbiter will carry out for the International Space Station (ISS), and final ordinance installation.
“Pending Program approval, S0024, the FRCS load, will pick up Wednesday morning with QD (Quick Disconnect) mates (and will hold at that point),” noted processing information on L2. “S5009, Final Ordnance Installation, is tentatively scheduled for Friday, February 13, 2009.”
“Are also in the process of re-laying out their schedule, the overall plan to get to the February 22 launch date. Flight Design folks are still working to look at increasing forward RCS load; will have that answer no later than Wednesday morning.”
In order to launch this month, engineers are conducting a series of tests - along with the evaluation of risk assessments - which will ultimately result in the flight rationale required by the FRR.
Tests and evaluations are continuing this week at no less than six facilities, involving NASA and numerous contractors relating to the systems linked with the FCVs.
...
Nel caso peggiore potrebbe esserci un ritardo di due mesi per permettere la ri-progettazione della valvola.
... e infatti anch'io sto aspettando di aprire il thread dedicato all'STS-119, non vorrei mai che poi finisse come la 125... :D
Le voci in effetti sono sempre più insistenti su un possibile ulteriore ritardo...
... e infatti anch'io sto aspettando di aprire il thread dedicato all'STS-119, non vorrei mai che poi finisse come la 125... :D
Le voci in effetti sono sempre più insistenti su un possibile ulteriore ritardo...
Per ora è stato spostato (http://www.nasaspaceflight.com/2009/02/sts-119prcb-on-fcvs-moves-net-to-february-27/) al 27..
http://www-pao.ksc.nasa.gov/kscpao/images/medium/2009-1951-m.jpg
CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians install three gaseous hydrogen flow control valves on space shuttle Discovery. The valves were retested after installation. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have worked to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Space Shuttle Program managers decided to replace Discovery's valves with others that have undergone a detailed eddy current inspection. Program managers will review the testing and determine whether to meet on March 6 for the Flight Readiness Review for the STS-119 mission. Launch of Discovery tentatively is targeted for March 12. Photo credit: NASA/Chris Rhodes
link (http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=40031)
http://www-pao.ksc.nasa.gov/kscpao/images/medium/2009-1873-m.jpg
CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians have removed space shuttle Discovery's three gaseous hydrogen flow control valves, two of which will undergo detailed inspection. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have been working to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Approximately 4,000 images of each valve removed will be reviewed for evidence of cracks. Valves that have flown fewer times will be installed in Discovery. NASA's Space Shuttle Program has established a plan that could support shuttle Discovery's launch to the International Space Station, tentatively targeted for March 12. An exact target launch date will be determined as work on the valves progresses. Photo credit: NASA/Dimitri Gerondidakis
link (http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=39965)
Una delle famose valvole:
http://www-pao.ksc.nasa.gov/kscpao/images/medium/2009-1876-m.jpg
CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a technician holds one of space shuttle Discovery's gaseous hydrogen flow control valves after its removal. Two of the three valves being removed will undergo detailed inspection. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have been working to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Approximately 4,000 images of each valve removed will be reviewed for evidence of cracks. Valves that have flown fewer times will be installed in Discovery. NASA's Space Shuttle Program has established a plan that could support shuttle Discovery's launch to the International Space Station, tentatively targeted for March 12. An exact target launch date will be determined as work on the valves progresses. Photo credit: NASA/Dimitri Gerondidakis
link (http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=39968)
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