View Full Version : [Space] NASA-ESA - Hubble Space Telescope
Cancellata l'ultima missione di servizio per Hubble (SM4):
NASA ha annunciato ieri di aver ufficialmente cancellato l'ultima servicing mission (SM-4) per il telescopio spaziale Hubble (HST) prevista per il 2006 con lo scopo di installare due nuovi strumenti già costruiti e sistemare i giroscopi non funzionanti (4 su 6 ancora funzionano, e 3 sono il minimo per continuare gli esperimenti scientifici) e controllare le batterie che stanno degrandandosi (sono ancora le originali).
La motivazione è essenzialmente legata alll'impossibilità di preparare in tempi utili una missione shuttle con la predisposizione per le riparazioni in orbita della navetta in caso di problema simil-Columbia, in assenza si appoggio all'ISS che garantirebbe il soccorso all'equipaggio, e quindi per risparmiare soldi come previsto dal nuovo piano presentato dal presidente Bush.
Il destino di Hubble rimane quindi incerto, dato che è difficile pensare che possa arrivare al 2011 in queste condizioni (data in cui dovrebbe entrare in servizio il sostituto, il nuovo James Webb Space Telescope). E' probabile che verrà fatto deorbitare entro il 2007.
http://www.spaceflightnow.com/news/n0304/30hubblegyro/hubble.jpg
NASA Cancels Shuttle Mission to Service Hubble
WASHINGTON -- Two days after U.S. President George W. Bush unveiled a new NASA vision requiring a shift in the space agency’s spending priorities, NASA announced that it was curtailing any further space shuttle missions to the Hubble Space Telescope.
Launched aboard the space shuttle in 1990, Hubble has been serviced by astronauts four times since then. The last such mission was in 2002.
NASA had planned to visit Hubble one last time in 2006 to change out instruments and replace its gyroscopes with the intent of keeping the telescope in service until at least 2011, when its heir apparent, the James Webb Space Telescope, is expected to launch.
Scrapping the final servicing mission raises the likelihood that Hubble will fail before Webb is on orbit.
NASA officials said the cancellation of the Hubble servicing mission was driven by concerns about astronaut safety -- heightened in the wake of the Columbia disaster -- not budget issues.
NASA chief scientist John Grunsfeld said conducting the Hubble servicing mission without violating the safety mandates issued by the Columbia Accident Investigation Board would have required the development of potentially costly inspection and repair techniques not otherwise needed.
Because a shuttle visiting the Hubble could not reach the International Space Station if something went wrong, Grunsfeld said NASA would have to have a second shuttle on the launch pad and ready to conduct an orbiter-to-orbiter rescue in an emergency.
Grunsfeld said the decision, announced by NASA Administrator Sean O’Keefe on Friday, was driven in part by the need to make tough choices in light of the president’s new vision.
"If we had plans to fly the space shuttle for another 15 years, this is an investment that we might have made to develop for all those rescue scenarios," Grunsfeld said.
Bush stated that all human spaceflight would be directed to support the effort of putting people on the Moon and Mars. The shuttle, which is the only means by which NASA could service Hubble, is to be devoted to finishing construction of the space station.
Astronomers had been concerned since Bush's speech that there "wasn't much wiggle room" to allow for further servicing of Hubble given the new vision, as one astronomer put it.
Kevin Marvel, an official with the American Astronomical Society, confirmed that the NASA chief had decided to cancel Hubble Servicing Mission 4 and had held a meeting with NASA employees today to announce that decision.
Marvel also said that Steve Beckwith, director of the Space Telescope Science Institute, which operates Hubble, held a meeting with his staff at about 3 p.m. EST (2000 GMT) Friday to tell them of O'Keefe's decision.
Marvel said the servicing mission would have prolonged Hubble's life and enhanced its capability with the addition of two instruments.
"Our situation as the [American] Astronomical Society is that we're concerned with the decision," Marvel said. "We haven't taken a position at this point but we're actively trying to learn the details."
Marvel added: "Without extending Hubble's lifetime the science that's currently being done and planned to be done with the new instruments would obviously not be achievable, and that would be an impact on the astronomy community."
Grunsfeld, a left-handed astronaut who earned the nickname "southpaw savante" for the hand he had in the 2002 Hubble servicing mission, said the decision not to return to the telescope was the right choice to make in light of NASA's new mandate.
But that does not make it any easier to let go, he said.
"I have been described by someone as a Hubble hugger because quite literally I have hugged the Hubble, so this is a hard one," Grunsfeld said.
NASA cancels final Hubble telescope servicing mission
A final planned shuttle mission to service and upgrade the Hubble Space Telescope, one of the most scientifically productive spacecraft ever launched, has been cancelled, primarily because of post-Columbia safety concerns and a new directive to retire the shuttle by 2010, NASA officials said today.
"This is sort of a sad day that we have to announce this," said NASA Chief Scientist John Grunsfeld, an astronaut who helped upgrade Hubble in 2002. "But I have to tell you, as somebody very close to the project, I can tell you they made the right decision. It's one that's in the best interest of NASA."
The decision means an advanced camera and light-splitting spectrograph - both already built - will not be installed. It also leaves Hubble's continued operation at the mercy of its aging gyroscopes, batteries and other equipment.
Based on the past performance of the gyros and other gear, engineers believe the observatory has a 50-50 chance of remaining in operation until mid 2007, three years shy of when NASA had earlier planned to retire the observatory.
Hubble's replacement, the James Webb Space Telescope, will not be launched until around 2011 at the earliest. Foregoing the final servicing mission means the gap between Hubble and Webb will stretch years longer than scientists had hoped.
"We're going to try to get as much life as we can out of the Hubble Space Telecope," Grunsfeld said. "We have a commitment from the office of space science that we will continue to support the research and analysis work even beyond (Hubble's demise)."
NASA Administrator O'Keefe told engineers and scientists at NASA's Goddard Spaceflight Center that his decision was based on a variety of factors, including a recommendation by the Columbia Accident Investigation Board that would require an autonomous tile repair capability for flights not bound for the international space station.
Hubble Servicing Mission 4, or SM-4, was the final flight on NASA's launch manifest that wasn't bound for the space station, where the crew of a crippled shuttle could attempt repairs or await rescue. The CAIB recommendation would have required NASA to develop stand-alone repair techniques for a single flight.
Grunsfeld said the cost of that effort, coupled with the Bush administration's recent directive to complete space station assembly and retire the shuttle fleet by 2010, left little choice.
"The president laid out for us a plan for space exploration," Grunsfeld said. "As part of that, he directed us to use this precious resource, the space shuttle, with a priority of completing the international space station and then retiring the shuttle.
"And so as part of that, when you look at what it would take to support this one single-use unique mission ... in light of retiring the shuttle, kind of pushed the decision over the edge and allowed the administrator to make that decision. As a result, this decision is reflected in the president's budget, which will come out on Feb. 2."
Hubble supporters were devastated.
"People here are brushing off their resumes," said one official at the Space Telescope Science Institute at Johns Hopkins University in Baltimore. "Hubble has been such a crown jewel for NASA, I would have hoped it would have tilted the balance the other way. ... It's been a sad day. It was like walking around a funeral home."
Before the Columbia disaster, NASA had planned to launch a final servicing mission to install the Cosmic Origins Spectrograph and a new, third-generation Wide Field Camera. Spacewalking astronauts also planned to replace stabilizing gyroscopes, aging batteries and other equipment in a bid to keep Hubble healthy until 2010 or so.
Only four of the telescope's six gyroscopes are operational and at least three are needed to continue scientific operations. Engineers hope to develop software that will allow the observatory to function with two gyros, but that work is not yet complete.
How long Hubble might continue to operate without another servicing mission is anybody's guess.
"The answer to how long it can last is completely probabilistic," said a project scientist who asked not to be named. "Who knows what will fail first? The two things we have always been most concerned with are the gyros and the batteries, both of which SM-4 would have addressed."
Based on the past performance of the gyroscopes, "it's our guess we have two years to go with 50 percent probability before we're down to two gyros," he said. "But it could be tomorrow and it could be eight years (from now).
"We need three gyros to do business as usual. We believe we can develop software to operate with two gyros and do 70 percent of the science the community would like to do. And indeed, headquarters had committed itself to asking Goddard and the institute to develop two-gyro mode several months ago. So clearly, we will do that."
That effort probably would keep Hubble operational into the mid 2007 time frame, but there are no guarantees. Batteries are another potential issue.
"The batteries are the original batteries, they are way past their experience baseline now," the astronomer said. "They are showing teeny little idiosyncratic signs of aging that no one really knows how to interpret. That's another wild card. And then, of course, you can name other things that could interrupt operations."
Up in the air is the fate of the Space Telescope Science Institute and the costly instruments already built for SM-4.
"The Cosmic Origins Spectrograph and the Wide Field 3 are almost complete and they are both fantastic instruments. We're really going to scratch our heads and find a good way to get the science out of those," Grunsfeld said.
"The various options that we are looking at, nothing definitive, but one possibility is that we find a way to incorporate the opportunity for those instruments to fly in ... our medium-class Explorer missions," he said.
"For instance the Origins Spectrograph could be combined with a relatively small mirror -- a one- or a one-and-a-half-meter mirror -- and still do the high-priority science."
Hubble, Its Fate Sealed, 'Has a Place in Everybody's Heart'
It was hard for astronomers to argue with astronaut and astrophysicist John Grunsfeld when he announced that the Hubble Space Telescope would no longer be serviced again, meaning the venerable observatory's days, or at least its years, were numbered.
Now chief scientist at NASA, Grunsfeld flew aboard the space shuttle Columbia's March 2002 mission to attach a new camera to Hubble, he took along an important science paper written by Edwin Hubble, for whom the telescope was named.
Edwin Hubble discovered in the 1920s that all galaxies are receding from each other -- that the universe is expanding.
Grunsfeld presented the decades-old paper to the American Astronomical Society (AAS) at a Seattle meeting in January 2003 and said, according to AAS president Catherine Pilachowski, that "he knew how dangerous the shuttle was but that the astronauts knew how important Hubble is to scientists and to everyone in the world."
Edwin Hubble's science paper, having flown to the telescope that bears his name, is now on the wall of the AAS headquarters in Washington, DC. The shuttle, it turned out, was dangerous, as seven of Grunsfeld's colleagues learned less than a month later when Columbia disintegrated upon re-entry.
On Friday, Grunsfeld confirmed what many astronomers feared, that Hubble would not be serviced again. The next time it fails, it is done. He cited astronaut safety as the primary reason for the decision.
"We all feel it as a devastating blow," Pilachowski said in a telephone interview from her home, just hours after NASA administrator Sean O'Keefe told a group of NASA employees about the decision.
Pilachowski represents more than 6,000 members, many of them working professional astronomers. "It was sort of sense of shock and disbelief on everyone's face," she said.
For anyone who thought only the public is wowed by Hubble's jaw-dropping images, Pilachowski said, "We astronomers see the pictures and they take our breath away. And we also see the incredible science." She said the decision was surely difficult for NASA officials, too.
The AAS president said initial frustration is likely to grow into appreciation for the decision, given the concern for human safety.
There is more to the decision, though. Under President George W. Bush's new space plan, the shuttle is to be devoted to finishing the construction of the International Space Station and then the fleet will be retired. That alone seemed to doom Hubble earlier in the week, when Bush announced his vision. Grunsfeld cited the Columbia Accident Investigation Board recommendation requiring a second shuttle be on the launch pad and ready to rescue astronauts doing a Hubble upgrade.
None of this can remove all the sting for astronomers losing the greatest astrophotography machine of all time. It is to be replaced in 2011 by a better observatory, the James Webb Space Telescope, but it's doubtful Hubble can last that long without being serviced.
"Hubble is a premier facility," Pilachowski said. "Hubble has a special place in everybody's heart."
Indeed, the observatory, launched in 1990, is often the only telescope that comes to the lips of the average person -- in a bar, a mall or a school -- asked to name a telescope.
Hubble has also done "really outstanding science," Pilachowski said and other astronomers agree. "To think of its premature end is just a hard thing to swallow."
Had it been serviced one more time, Hubble might have survived through 2011. Without servicing, it's unknown how long Hubble will last. It is in need of replacement gyroscopes to keep it properly pointed. And the servicing mission, tentatively planned until Friday, would have installed two new instruments to enhance Hubble's capabilities.
Astronomers are already contemplating creative ways to keep it online.
"It's not as if they're about to turn Hubble off," Pilachowski said. "We're hopeful that Hubble will continue to be productive for several more years." She added that researchers must now "think very hard about how do we get the most out of these last few years of Hubble."
duchetto
17-01-2004, 13:27
un vero peccato :(
Star trek
17-01-2004, 13:30
oh oh!!! se lo buttano via lo prendo io!!
:D bye
jumpermax
17-01-2004, 14:23
cmq
a parte che c'è già in orbita solare un altro telescopio spaziale
http://www.spitzer.caltech.edu/ che non durerà molto è vero (la missione prevede 2 anni e mezzo ossia fino al 2006
hubble sarebbe cmq stato rimpiazzato nel 2011
http://www.spaceflightnow.com/news/n0401/16hubblesm4/
Hubble's replacement, the James Webb Space Telescope, will not be launched until around 2011 at the earliest. Foregoing the final servicing mission means the gap between Hubble and Webb will stretch years longer than scientists had hoped.
E quest'anno poi dovrebbe :confused: attivarsi anche il VLST europeo... dai di occhi puntati ne abbiamo! ;)
ominiverdi
17-01-2004, 14:54
THE JAMES WEBB SPACE TELESCOPE
JWST will be a large, infrared-optimized space telescope. It will have an 18-segment, 6.5-meter primary mirror. It is being built by Northrop Grumman Space Technology and is scheduled to launch in 2011.
http://ngst.gsfc.nasa.gov/
c'e' anche un'immagine del telescopio
jumpermax
17-01-2004, 15:03
Originariamente inviato da ominiverdi
THE JAMES WEBB SPACE TELESCOPE
JWST will be a large, infrared-optimized space telescope. It will have an 18-segment, 6.5-meter primary mirror. It is being built by Northrop Grumman Space Technology and is scheduled to launch in 2011.
http://ngst.gsfc.nasa.gov/
c'e' anche un'immagine del telescopio
:eek: uno specchio di 6 metri e mezzo? notevole.... cmq mi sembra piùà simile allo Spitzer che ad Hubble...
http://www.pbs.org/newshour/science/hubble/mission.html
Although the length of Hubble's mission is still unclear, NASA has been hard at work developing another telescope that will help astronomers amplify their understanding of the universe. The James Webb Space Telescope, scheduled to launch in 2011, differs from Hubble in several ways. NASA hopes the new telescope will help scientists look even deeper into space to see the "first stars and galaxies in the universe," according to the agency's Web site.
One key difference between the two telescopes is that the new one will have better instruments for seeing infrared light, which has a longer wavelength and is seen at the far reaches of the universe. Meanwhile, Hubble is better at detecting the shorter wavelengths of light that can be seen with the human eye. Because of these differences between the two telescopes, the NASA panel recommended that the two telescopes' operations overlap so scientists can study both types of images from certain objects.
The James Webb Space Telescope's mirror will be six times larger than the one on Hubble, giving it a greater ability to collect light. The new telescope will also operate much farther from Earth -- some 940,000 miles away -- making it easier to operate than Hubble. Once in place, it will orbit the sun, unlike Hubble, which orbits the Earth. Its distance from Earth will also make it impossible for astronauts to reach it and make repairs.
The NASA-commissioned panel reported it was "impressed by the progress that has been made by the JWST [James Webb Space Telescope] team." However, after siting the amount of time it took to develop other observatories, the panel cautioned that the launch date "might be delayed substantially beyond 2011."
Originariamente inviato da GioFX
Il destino di Hubble rimane quindi incerto, dato che è difficile pensare che possa arrivare al 2011 in queste condizioni (data in cui dovrebbe entrare in servizio il sostituto, il nuovo James Webb Space Telescope). E' probabile che verrà fatto deorbitare entro il 2007.
e al James Webb Space Telescope che mi riferivo quando parlavo del successore dell'Hubble
e mi chiedo se non sarebbe meglio accellerare la sua messa in opera piuttosto che continuare a mandare sonde su marte da qui al 2010 a contare i ciottoli marziani che ancora non siano stati contati dalle sonde precedenti
ominiverdi
17-01-2004, 15:26
Originariamente inviato da fabio69
e al James Webb Space Telescope che mi riferivo quando parlavo del successore dell'Hubble
e mi chiedo se non sarebbe meglio accellerare la sua messa in opera piuttosto che continuare a mandare sonde su marte da qui al 2010 a contare i ciottoli marziani che ancora non siano stati contati dalle sonde precedenti
scusa ma che centrano i ciottoli, le attuali missioni non sono forse per cercare acqua o stabilire se vi fosse stata acqua in passato su marte, e analizzare anche il suolo marziano molto in profondita', oltre che analisi sull' atmosfera, cosa che le precedenti missioni non hanno fatto?
jumpermax
17-01-2004, 15:35
Originariamente inviato da fabio69
e al James Webb Space Telescope che mi riferivo quando parlavo del successore dell'Hubble
e mi chiedo se non sarebbe meglio accellerare la sua messa in opera piuttosto che continuare a mandare sonde su marte da qui al 2010 a contare i ciottoli marziani che ancora non siano stati contati dalle sonde precedenti
un analisi un tantino terra terra fabio... a parte che è in orbita da sei mesi lo spitzer, http://www.spitzer.caltech.edu/ e ci resterà altri 2 anni
le missioni su marte sono fondamentali per capire meglio anche la geologia terreste, nuove ipotesi sulla formazione della vita, sulla formazione del sistema solare ecc ecc... Oltre che ovviamente capire come e dove eventualmente iniziare una colonizzazione del pianeta... in un futuro lontano spero non troppo
jumpermax
17-01-2004, 15:38
a proposito ragazzi... c'è qualcun altro che ci invia cartoline non solo spirit...
http://photojournal.jpl.nasa.gov/browse/PIA04913.jpg
chissarammmai? La sonda cassini of course, che a luglio raggiungerà saturno. La foto è stata presa a circa 111 milioni di km di distanza dal pianeta...
ominiverdi
17-01-2004, 15:58
La Nasa sta iniziando a costruire il James Webb telescope, capace di spingere il suo sguardo fino a 14 miliardi di anni luce: quando il nostro universo stava prendendo forma
Era una splendida mattina di primavera quando, il 24 aprile 1990, lo shuttle Discovery portò nello spazio un occhio di 2,4 metri di diametro: l'Hubble space telescope. Il suo compito: esplorare l'universo più lontano e gli oggetti più misteriosi del cosmo.
A distanza di 13 anni è giunto il momento di costruire il successore. Si chiamerà James Webb space telescope, dal nome dell'amministratore della Nasa che guidò l'ente fino al 1968, preparando la strada allo sbarco dell'uomo sulla Luna. Lo specchio per raccogliere la luce sarà due volte e mezzo più grande e composto di berilio (elemento molto riflettente). Una volta in orbita, catturerà le radiazioni emesse da oggetti nati pochi milioni di anni dopo il Big bang e oggi distanti 13-14 miliardi di anni luce.
"Il James Webb andrà a occupare un punto dello spazio a 1 milione e mezzo di km dalla Terra, mentre ora lo Hubble è a circa 600 km d'altezza. L'area in cui si collocherà il nuovo telescopio si trova in un particolare equilibrio gravitazionale tra il Sole e il nostro pianeta: per mantenerlo in orbita saranno necessari pochi interventi di controllo della stabilità" anticipa Philip Stahl del Marshall space flight center, dove si provano i prototipi degli specchi. Il James Webb sarà dotato di tre strumenti che dovranno essere perfetti, perché sarà irraggiungibile da qualunque shuttle attuale o di prossima costruzione.
Il cuore del telescopio sarà la NirCam (Near-infrared camera): un rilevatore di immagini nell'infrarosso, lunghezza d'onda che serve per vedere gli oggetti più antichi e freddi. Riuscirà anche a captare la luce di eventuali grossi pianeti attorno alle stelle più vicine alla Terra.
Il secondo strumento sarà uno spettrometro, capace di stabilire composizione, temperatura e altre caratteristiche fisiche degli oggetti osservati. Il terzo dispositivo osserverà l'infrarosso a una lunghezza leggermente diversa rispetto ai precedenti: una radiazione emessa da galassie e stelle molto antiche. Inoltre potrà osservare gli oggetti che esistono oltre le nubi di polveri cosmiche. Spiega Greg Davidson, codirettore delle ricerche della Ngst, società che costruirà il telescopio: "Dal James Webb gli astrofisici si aspettano risposte su cosmologia e struttura dell'universo, origine ed evoluzione delle galassie, nascita e formazione delle stelle, evoluzione dei sistemi planetari extrasolari".
Il telescopio costerà circa 850 milioni di dollari, dei quali 200 verranno forniti dall'Agenzia spaziale europea e 50 da quella canadese. È programmato per funzionare almeno cinque anni, ma si spera di prolungarlo per dieci. Il progetto è ormai in fase operativa e il lancio è previsto per il 2011 a bordo di un razzo europeo Ariane 5. E lo Hubble che fine farà? Fino al disastro del Columbia si pensava di riportarlo a Terra con una missione che sarebbe avvenuta entro il 2010, ma ora l'idea sembra essere accantonata. Nel 2004 sarebbe dovuta partire la quinta missione di servizio, ma è stata spostata oltre il 2005.
Proprio in queste settimane una commissione di astronomi ha chiesto alla Nasa di prolungarne la vita fino a quando entrerà in funzione il James Webb. Sul tavolo dell'ente spaziale ci sono tre opzioni. La prima potrebbe dar vita a due missioni di mantenimento del telescopio per farlo durare il più a lungo possibile; la seconda prevede una sola missione e la sua fine verso il 2008; la terza nessuna missione, se lo shuttle non raggiungerà il livello di sicurezza richiesto dopo l'incidente al Columbia. D'altra parte lo Hubble si trova su un'orbita che non permette allo shuttle di raggiungere la stazione orbitante in caso di avaria, e ciò va contro i piani di sicurezza.
Comunque vadano le cose, il contributo del telescopio per la comprensione dell'universo è stato immenso. Ha eseguito oltre 300 mila osservazioni e studiato più di 14 mila oggetti, inviando a Terra qualcosa come 3,5 terabyte di dati (tali da riempire 3 miliardi e mezzo di dischetti da computer). Era giusto dunque immaginarlo tra le capsule Apollo e i rover marziani al National air and space museum dello Smithsonian institution di Washington, ma il suo destino potrebbe essere quello di diventare polvere al rientro nell'atmosfera.
http://www.panorama.it/scienze/ambiente/articolo/ix1-A020001020802
--
edit: se ho ben capito questa e' la prima immagine scattata da un prototipo di james webb http://ngst.gsfc.nasa.gov/science/NGC891.html
jumpermax
17-01-2004, 16:08
Appunto dalla descrizione è pari pari allo spitzer anche lui in orbita solare. Cmq la questione hubble sembra essere anche una questione di sicurezza non solo di costi... non so. O è un eccesso di zelo o davvero lo shuttle è messo peggio di quanto non sembri...
Originariamente inviato da jumpermax
Appunto dalla descrizione è pari pari allo spitzer anche lui in orbita solare. Cmq la questione hubble sembra essere anche una questione di sicurezza non solo di costi... non so. O è un eccesso di zelo o davvero lo shuttle è messo peggio di quanto non sembri...
Credo che non si voglia piu' rischiare... direi che e' questione di costi e di sicurezza...
Star trek
17-01-2004, 16:20
Originariamente inviato da jumpermax
a proposito ragazzi... c'è qualcun altro che ci invia cartoline non solo spirit...
http://photojournal.jpl.nasa.gov/browse/PIA04913.jpg
chissarammmai? La sonda cassini of course, che a luglio raggiungerà saturno. La foto è stata presa a circa 111 milioni di km di distanza dal pianeta...
boh a me sembra molto 3d enginnered
jumpermax
17-01-2004, 20:21
Originariamente inviato da Star trek
boh a me sembra molto 3d enginnered
si certo come no... e le foto di hubble invece le fanno con photoshop direttamente... :rolleyes: ecco la pagina della foto
http://photojournal.jpl.nasa.gov/catalog/PIA04913
Io non capisco... tutti pronti a credere ad alieni e facce nascoste sul pianeta marte e di fronte a dati scientifici ed immagini autentiche hop si tratta di un falso...
jumpermax
17-01-2004, 20:49
ah e per inciso la missione non è solo americana, c'è anche una parte sviluppata dall'esa che dovrebbe atterrare su Titano.
Una missione credo molto più interessante di quella su marte... la davvero mai tecnologia umana ha poggiato piede...
http://saturn.jpl.nasa.gov/spacecraft/instruments-huygens.cfm
http://www.esa.int/export/esaCP/SEMOGY374OD_index_0.html
Frank1962
17-01-2004, 20:57
http://photojournal.jpl.nasa.gov/jpegMod/PIA04913_modest.jpg
bellissima!!! ....se fate attenzione si vedono pure i satelliti!!! :eek:
jumpermax
17-01-2004, 21:01
Originariamente inviato da Frank1962
bellissima!!! ....se fate attenzione si vedono pure i satelliti!!! :eek:
:eek: :eek: :eek: e io che credevo di aver trovato un altro pixel bruciato... :D :D :D :D
ominiverdi
17-01-2004, 21:15
Originariamente inviato da jumpermax
ah e per inciso la missione non è solo americana, c'è anche una parte sviluppata dall'esa che dovrebbe atterrare su Titano.
Una missione credo molto più interessante di quella su marte... la davvero mai tecnologia umana ha poggiato piede...
http://saturn.jpl.nasa.gov/spacecraft/instruments-huygens.cfm
http://www.esa.int/export/esaCP/SEMOGY374OD_index_0.html
oltre a titano, del quale gli scienziati definiscono la sua atmosfera "misteriosa", qualcuno sa se sono previste delle missioni alla volta di IO ed Europa, per studiare atmosfera e suolo?
galileo ha fornito immagini davvero interessanti di questi due satelliti, tempo fa lessi che secondo alcuni scienziati vi potrebbero essere le condizioni affinche' si sviluppino forme di vita...
molto curioso l'aspetto di IO, non e' troppo "invitante", sembra un formaggio ammuffito con una specie di pus sopra :eek:
http://photojournal.jpl.nasa.gov/catalog/PIA02527
http://galileo.jpl.nasa.gov/images/io/ioimages.html
http://galileo.jpl.nasa.gov/moons/io.html
http://galileo.jpl.nasa.gov/moons/europa.html
ominiverdi
17-01-2004, 21:48
tornando IT su hubble, a me fanno letteralmente cadere la mascella le foto "deep field", dove si vedono centinaia e migliaia di galassie in un solo scatto, davvero d'impatto...
http://imgsrc.hubblesite.org/hu/db/2003/18/images/a/formats/full_jpg.jpg
http://hubblesite.org/newscenter/newsdesk/archive/releases/1996/01/
foto e video hubble:
http://hubblesite.org/newscenter/newsdesk/archive/releases/
http://hubble.nasa.gov/image-gallery/
http://www.skyimagelab.com/hubphot.html
Originariamente inviato da ominiverdi
scusa ma che centrano i ciottoli, le attuali missioni non sono forse per cercare acqua o stabilire se vi fosse stata acqua in passato su marte, e analizzare anche il suolo marziano molto in profondita', oltre che analisi sull' atmosfera, cosa che le precedenti missioni non hanno fatto?
sull'atmosfera si sa più o meno tutto da decenni in particolare dalle missioni viking
il punto sta nel trovare sta benedetta acqua di cui nelle varie missioni si sono raccolti indizi e poco altro
vedremo se ci riusciranno
Originariamente inviato da jumpermax
un analisi un tantino terra terra fabio... a parte che è in orbita da sei mesi lo spitzer, http://www.spitzer.caltech.edu/ e ci resterà altri 2 anni
le missioni su marte sono fondamentali per capire meglio anche la geologia terreste, nuove ipotesi sulla formazione della vita, sulla formazione del sistema solare ecc ecc... Oltre che ovviamente capire come e dove eventualmente iniziare una colonizzazione del pianeta... in un futuro lontano spero non troppo
si avevo letto il rimando che avevi già fatto su quel telescopio ed era una risposta anche a quello
sul fatto che le missioni su marte siano fondamentali avrei qualche dubbio
geologicamente marteè un pianeta morto e di vita non vi è nessuna traccia com'era lecito aspettarsi
sull'origine della formazione del sistema solare magari sarebbero più indicate missioni su comete o asteroidi (anche se ve ne sono in attuazione alcune)
quanto al viaggio e alla colonizzazione ho l'impressione che se non si riuscira ad approntare un modo più efficiente, sicuro ma soprattutto economico per un viaggio simile, altro che 2030 mi sa che il primo sbarco avverrà nel 2050 o giù di lì
intanto aspettiamo qualche scoperta fondamentale sul pianeta rosso rispetto alle già citate missioni viking
credo che tarderà ad arrivare ;)
jumpermax
18-01-2004, 16:38
Originariamente inviato da fabio69
sull'atmosfera si sa più o meno tutto da decenni in particolare dalle missioni viking
il punto sta nel trovare sta benedetta acqua di cui nelle varie missioni si sono raccolti indizi e poco altro
vedremo se ci riusciranno
più o meno tutto... va bene che l'atmosfera marziana è più semplice di quella terrestre ma pensare di sapere tutto sull'atmosfera di un pianeta con 3-4 satelliti in orbita mi sembra eccessivo.....
Originariamente inviato da jumpermax
più o meno tutto... va bene che l'atmosfera marziana è più semplice di quella terrestre ma pensare di sapere tutto sull'atmosfera di un pianeta con 3-4 satelliti in orbita mi sembra eccessivo.....
già ma poi all'esa e anche alla nasa non si accontentano
secondo loro le sonde dovranno appurare se vi è acqua allo stato solido nascosta in qualche meandro della superficie marziana, riscontri atmosferici e analisi dettagliata della superficie
e naturalmente appurare se vi è stata vita anzi se vi è tutt'ora, e ti pareva
dichiarazioni vagamente propagandistiche volte a "pompare" le missioni
che marte sia un pianeta sterile da chissà quanti miliardi di anni non vi erano più dubbi dalle missioni viking
cmq per studiare l'atmosfera sono più adatte le sonde al suolo che non quelle in orbita
jumpermax
18-01-2004, 17:02
Originariamente inviato da fabio69
già ma poi all'esa e anche alla nasa non si accontentano
secondo loro le sonde dovranno appurare se vi è acqua allo stato solido nascosta in qualche meandro della superficie marziana, riscontri atmosferici e analisi dettagliata della superficie
e naturalmente appurare se vi è stata vita anzi se vi è tutt'ora, e ti pareva
dichiarazioni vagamente propagandistiche volte a "pompare" le missioni
che marte sia un pianeta sterile da chissà quanti miliardi di anni non vi erano più dubbi dalle missioni viking
cmq per studiare l'atmosfera sono più adatte le sonde al suolo che non quelle in orbita
Io proprio non avrei tutte queste certezze. Il viking ha esplorato una porzione infinitesimale di superficie, nessuna esplorazione in profondità solo 3 test per determinare la possibilità di vita. Di quello che c'è nel sottosuolo marziano non sappiamo un accidente, figurati che manco sapevamo l'esatta composizione del suolo del sito di spirit fintanto che il robot non ci ha appoggiato le ruote. Serviranno decine di missioni per riuscire ad avere informazioni sufficenti a pianificare una missione umana, oltre che ovviamente per affinare una tecnologia robotica in grado di durare su marte più di qualche mese e di compiere azioni decisamente più impegnative di qualche analisi del terreno. Che dire? E' l'unico pianeta colonizzabile che abbiamo a portata di mano. Direi che l'interesse è più che una semplice speculazione...
jumpermax
18-01-2004, 17:06
e per inciso... non abbiamo minimamente idea di cosa potrebbe succedere se un batterio alieno entrasse nel nostro ecosistema... o decidiamo che su marte non ci mettiamo piede oppure sarà il caso di fare attettenzione a quello che ci si può portare a casa...
Ho letto su "Le Scienze" di dicembre, mi pare, che e' stato fatto un test.
C'e' un deserto in sud america, a poche centinaia di chilometri dalla foresta amazzonica, dove piove mi pare 20 volte meno che nel sahara. Ecco, in questo deserto sono stati fatti gli esperimenti per la ricerca di resti organici che vengono fatti dalle sonde su marte.
Il risultato?
Bene, se una sonda aliena fosse atterrata li' e avesse cercato la vita come noi la cerchiamo su Marte, il risultato sarebbe stato che sulla terra non ci sono forme di vita :D
ominiverdi
18-01-2004, 19:16
probabile (praticamente certo) si trattasse del deserto di atacama, in cile :D
http://www.intraisass.it/extra16.htm
Originariamente inviato da ominiverdi
probabile (praticamente certo) si trattasse del deserto di atacama, in cile :D
http://www.intraisass.it/extra16.htm
Si', adesso non mi ricordavo il nome, comunque e' piu' che possibile... ;)
Da Nytimes.com (http://www.nytimes.com/2004/01/17/science/17HUBB.html):
NASA Cancels Trip to Supply Hubble, Sealing Early Doom
By DENNIS OVERBYE
Published: January 17, 2004
Savor those cosmic postcards while you can. The National Aeronautics and Space Administration decreed an early death yesterday to one of its flagship missions and most celebrated successes, the Hubble Space Telescope.
In a midday meeting at the Goddard Space Flight Center in Greenbelt, Md., two days after President Bush ordered NASA to redirect its resources toward human exploration of the Moon and Mars, the agency's administrator, Sean O'Keefe, told the managers of the space telescope that there would be no more shuttle visits to maintain it.
A visit by astronauts to install a couple of the telescope's scientific instruments and replace the gyroscopes and batteries had been planned for next year. Without any more visits, the telescope, the crown jewel of astronomy for 10 years, will probably die in orbit sometime in 2007, depending on when its batteries or gyroscopes fail for good.
"It could die tomorrow, it could last to 2011," said Dr. Steven Beckwith, director of the Space Telescope Institute on the Johns Hopkins University campus in Baltimore. Dr. Beckwith said he and his colleagues were devastated.
At a news conference last night, Dr. John M. Grunsfeld, the agency's chief scientist and an astronaut who has been to the Hubble two times, called the the telescope the "best marriage of human spaceflight and science."
"It is a sad day that we have to announce this," Dr. Grunsfeld added.
As the news flashed around the world by e-mail, other astronomers joined the Hubble team in their shock. Dr. David N. Spergel, an astronomer at Princeton and a member of a committee that advises NASA on space science, called it a "double whammy" for astronomy. Not only was a telescope being lost, but $200 million worth of instruments that had been built to be added in the later shuttle mission will also be left on the ground, Dr. Spergel said.
Dr. Garth Illingworth, an astronomer at the University of California at Santa Cruz who is also on the advisory committee, said, "I think this is a mistake," noting that the Hubble was still doing work at the forefront of science.
Dr. Tod Lauer, of the National Optical Astronomy Observatories in Tucson, said, "This is a pretty nasty turn of events, coming immediately on the heels of `W's' endorsement of space exploration."
The demise of the Hubble will leave astronomers with no foreseeable prospect of a telescope in space operating primarily at visible wavelengths. The announcement also precludes hopes that astronomers had of using the Hubble in tandem with the James Webb Space Telescope, scheduled for launching in 2011 and which is being designed for infrared wavelengths, to study galaxies at the far reaches of time.
Ground-based telescopes like the 10-meter-diameter Kecks on Mauna Kea are growing more powerful, and the use of adaptive optics to tune out the blurring effects of the atmosphere lets them approach the resolution of the Hubble in limited cases. But they are blinded by the atmosphere to ultraviolet and infrared light.
Floating above the murky atmosphere of Earth, the Hubble, launched in 1990, has had the ability to see into the depths of space and time with unprecedented clarity, glimpsing galaxies that were under construction when the universe was half its present age and helping cosmologists chart how the mysterious "dark energy" has gradually taken over the expansion of the universe.
Periodic service calls by shuttle astronauts repaired a series of early problems and have continually refurbished the telescope and kept it at the fore of cosmic research. The mission next year would have left the telescope in good shape to continue working through the end of the decade, when NASA plans to bring it down. But the service missions are expensive, more than $500 million each.
More important, NASA officials say, after the Columbia catastrophe a year ago, the missions are also considered dangerous. The shuttles do not carry enough fuel to reach the space station in case of trouble.
In its report on the shuttle disaster last summer, the Columbia Accident Investigation Board recommended that there be a way to inspect and repair the shuttle's heat shields, which were damaged after the Columbia lifted off. That is easily conducted if the craft is at the space station, but not at the Hubble.
In his remarks to the astronomers on Friday, according to those present, Mr. O'Keefe referred to that recommendation and said it would be too difficult to develop that ability for a single trip to the telescope.
Given enough time, NASA might have developed the tools to do it, Dr. Grunsfeld said, but the decision to retire the shuttles in 2010 foreclosed that possibility.
"Cost was not an issue," he said.
Many astronomers, however, noting that the decision came on the heels of Mr. Bush's directive to NASA to reallocate $11 billion of its resources over the next five years into returning people to the Moon, said money was doubtless also a consideration.
Presenting the decision as a safety-related issue, the astronomers said, lessened the odds that it would be challenged, by, say NASA's Congressional overseers.
NASA is not completely off the hook as far as the Hubble is concerned. The agency is committed to bringing it back to Earth safely after its useful life ends. Until the Columbia accident, NASA had planned to retrieve the telescope with a shuttle and put it in the Smithsonian. Now the plan is to build a robotic rocket that would go up, attach itself to the telescope and fire its engine to brake Hubble out of orbit and drop it in the ocean.
Paradoxically, Dr. Spergel said, the cost of developing such a rocket, estimated at $300 million or more, would come out of the NASA astronomy budget. It is, he said, another double whammy.
One mission gets canceled, he said, and "what's our next mission, deorbit the telescope?"
For now, of course, the Hubble lives. Dr. Beckwith said: "We at the institute are devastated by the potential loss of Hubble. But we will do our absolute best to make the final years of its life the most glorious science you've ever seen."
Da Space.com:
Help for Hubble: Officials Mull Donations, Russian Service Mission
By Robert Roy Britt
Senior Science Writer
posted: 12:20 pm ET
21 January 2004
A SPACE.com Exclusive
Hubble Space Telescope operators plan to ask Russia for help in keeping the observatory alive and will even consider accepting private donations, which have already been offered.
Every idea under the Sun will be considered for maintaining the popular and scientifically valuable observatory even though NASA has decided to let it die.
"We're in the mode of pursuing every wacky concept out there," said Steven Beckwith, the director of the Space Telescope Science Institute (STScI), which operates Hubble for NASA.
The stakes are high.
Citing safety concerns, NASA declared Friday it would not go forward with a planned servicing mission in 2006, in which astronauts would repair defective pointing gyroscopes and install two new and powerful instruments on Hubble. The decision came two days after President Bush's call for NASA to refocus on human spaceflight with an eye toward returning to the Moon.
Without a servicing mission, Hubble has a life expectancy of, at most, 3-1/2 years if some creative solutions can be employed, Beckwith said today in a telephone interview.
No replacement
There is no other telescope in existence, or any slated to go online in the next decade, that can replace Hubble's optical view of the universe.
"You miss what the human eye can see," Beckwith said. "You miss all the visible." He likened the astronomers' expected plight to a soldier on the battlefield having to rely on night vision goggles.
Ground-based optical observatories struggle to overcome the blurring effects of Earth's atmosphere. At times, they achieve or exceed Hubble's capabilities, but only in narrow, very limited bands of the optical portion of the electromagnetic spectrum, the scientists' term for light.
NASA's new Spitzer Space Telescope views the universe in the infrared, akin to night-vision goggles, as will the planned James Webb Space Telescope, tentatively slated for launch in 2011. Even if Webb goes up -- and that is not certain yet -- it won't see visible light.
Meanwhile, the two new Hubble instruments are already built. The Wide Field Camera 3 and the Cosmic Origins Spectrograph cost a combined $167 million and would have provided unprecedented peeks into the formation of the cosmos, astronomers say. The camera is nearly ready at NASA's Goddard Space Flight Center and the spectrograph, which splits and analyzes light, is ready and waiting at Ball Aerospace Technology Corp. in Boulder, Colo.
They would have made Hubble 10 times more capable of examining the early universe, making Hubble's final years "the best ever," Beckwith said. "If you liked Hubble up to now you would have loved it after Servicing Mission 4."
No one knows what will become of the two instruments, but it is unlikely they could be adapted for use on any other telescope.
All options considered
Beckwith said there is no precedent in the history of astronomy for removing a telescope from operation before a better one is online. A classic example: A 100-inch telescope on Mt. Wilson, in California, was built in 1917. It was still in operation in 1948 when the 200-inch Palomar Observatory was opened, also in California.
Both are still in use.
"I've had a lot of e-mail from people who want to donate money to help keep Hubble alive," Beckwith said. He and his team will consider the feasibility of accepting donations but he said "billionaires might be needed."
NASA still plans a robotic mission to attach a device to Hubble that would safely deorbit and destroy it. STScI engineers will consider whether a similar robotic effort might instead service the observatory. " We don't know if that's technologically feasible," Beckwith said.
There might also be discussion with the European Space Agency (ESA), which partnered with NASA to fund the original development of Hubble. Beckwith said, though, that talks have likely already taken place at a high level between NASA and ESA and he's not sure "how much leeway we'll have."
Others have suggested that the Russians might be willing to send a manned mission to upgrade and service Hubble.
"The Russians probably have the capability to do it," Beckwith said, and he plans to pursue the possibility. "It's not necessarily politically likely, but it shows that we're going to take all ideas and put them on the table."
Survival mode
Hubble has six gyroscopes onboard used for pointing the telescope. They fail regularly -- several have been replaced during previous servicing missions -- and only four are operating now. Three are needed to make Hubble work.
Engineers are currently working on ways to point the telescope with just two gyroscopes. If they can't succeed, then gyroscope failures could end operations in less than three years, Beckwith said. In reality, the end could come any day.
Meanwhile, mission planners and engineers at the STScI, on the campus of Johns Hopkins University in Baltimore, will soon have a new set of tasks.
Beckwith will ask his employees to present options for possibly servicing Hubble or extend its life without servicing. They might cycle power off during certain portions of the observatory's orbit to conserve batteries. Or they might immediately turn off one of the four working gyros to maximize its lifetime.
Not dead yet
Whatever happens, Hubble is still a working observatory for the moment.
Beckwith will set up a committee of astronomers from inside the STScI and outside, in the general astronomy community, to advise him on a short-list of observations that should be done under the assumption that time is running out. That effort would be a "political process" involving hundreds of astronomers who regularly stand in line hoping to get approval for their proposed observation sessions on the telescope.
No one in astronomy questions the value of Hubble. Astronaut and astrophysicist John Grunsfeld, now NASA's chief scientist, flew into space and worked on Hubble during the last mission. "This is a hard one," he said of the decision to let the telescope go.
"We all feel it as a devastating blow," said Catherine Pilachowski, president of the 6,000-member American Astronomical Society.
Perhaps the most telling measure of Hubble's success comes by comparison. Operators of other telescope often make the claim, and rightfully so, that they've observed a distant object with resolution comparable to or exceeding that of Hubble. They do so on a limited basis in a narrow bandwidth, but they do it. And they are proud to point it out. Their desire to match what Hubble does so easily on a regular basis is always apparent.
"We enjoy being the gold standard," Beckwith said with some determination today, "and we will remain so."
The STScI will set up a web site within a week or so to take suggestions from the public and to communicate the status of the effort to save Hubble.
Da Space.com (http://space.com/scienceastronomy/hubble_public_040125.html):
Public Bombards Operators to Save Hubble
By Alex Dominguez
Associated Press
posted: 03:45 am ET
26 January 2004
BALTIMORE (AP) -- The operators of the Hubble Space Telescope are being bombarded by suggestions from the public on how to save the craft -- which NASA has decided not to service anymore -- and say they are considering all offers.
Of the hundreds of e-mails, about a quarter ask, "Why can't the Russians help?"
Others suggest towing it to the space station for repairs, said Bruce Margon, associate director for science at the Space Telescope Science Institute, which operates Hubble for NASA.
"They are enormously concerned, they are perplexed, they are angry," Margon said. "They ask 'What percentage of the NASA budget is this?' And we tell them it's about 1 percent."
The Baltimore-based institute will set up a Web site to take suggestions from the public, he said.
The suggestions started arriving after NASA said last week it won't send the space shuttle in 2006 to service the Hubble, a mission considered essential to enable the orbiting telescope to continue operating. The Hubble has revolutionized the study of astronomy with its striking images of the universe.
Instead, NASA will focus on President Bush's plans to send humans to the moon and Mars. Virtually all remaining missions of the shuttle, which also is being phased out, will be used to complete construction of the International Space Station.
As for the suggestions received so far for saving the Hubble telescope, Margon said the Russians might be able to help, but towing the Hubble to the space station is impractical because the two are in very different orbits.
The space station is in a lower orbit, and takes a much different path around the Earth. If the Hubble could be moved into that orbit, it is not clear whether the space telescope could work because of drag from the small amount of the Earth's atmosphere present at that altitude, he said.
Sen. Barbara Mikulski, D-Md., the ranking minority member of the Senate Appropriations subcommittee that oversees NASA's budget, said in a letter to NASA Administrator Sean O'Keefe on Wednesday that she was shocked by the decision given the Hubble's extraordinary contributions to science.
"I ask you to reconsider your decision and appoint an independent panel of outside experts to fully review and assess all of the issues surrounding another Hubble servicing mission," Mikulski said.
The 2006 mission was to be the fifth and final mission to the space telescope before its planned retirement in 2010. The Hubble will eventually fall out of orbit and crash to Earth, probably in 2011 or 2012.
"We feel that we should consider every conceivable idea to get back the last four to six years of discovery that Hubble was on the brink of making," Margon said.
NASA does eventually plan one final mission to Hubble, an as yet undesigned, unmanned rocket that will guide the space telescope back to Earth for a fiery crash into the Pacific. NASA originally planned to use the shuttle to retrieve Hubble and display it at the Smithsonian.
"That's part of the heartbreak, something is going to have to visit Hubble anyway," Margon said.
http://hubblesite.org/gallery/wallpaper
@_@
Originariamente inviato da GioFX
http://hubblesite.org/gallery/wallpaper
@_@
Mi accodo: @_@
Originariamente inviato da gpc
Mi accodo: @_@
E' anche per questo che si sono "sollevati" in centinaia di migliaia solo in america contro la decisione di O'Keefe in merito ad Hubble... perchè è da tutti considerata la più importante e riuscita missione scentifica astronomica. Motivazioni legate a problemi di sicurezza, certo (anche se non tutti pensano che sia solo questo), il problema è che comunque dovranno progettare un sistema automatico in grado di deobirtare Hubble per cadere in una remota regione di un'oceano... e non sarà cosa poco costosa. Pensando poi che il JWST non sarà lanciato prima del 2011...
duchetto
26-01-2004, 22:40
Originariamente inviato da GioFX
http://hubblesite.org/gallery/wallpaper
@_@
stupende queste immagini :eek:
soprattutto le nebulose con tutti quei colori...
NASA Chief: Hubble Decision Under Review
By Brian Berger
Space News Staff Writer
posted: 04:20 pm ET
26 January 2004
WASHINGTON -- Retired U.S. Navy Adm. Harold Gehman, the chairman of the now disbanded Columbia Accident Investigation Board, will be taking a second look at NASA's decision to curtail the use of the space shuttle for any further servicing of the Hubble Space Telescope, NASA Administrator Sean O'Keefe said Thursday.
O'Keefe said he has asked Gehman to review the decision to cancel what would have been the fifth and final Hubble servicing mission to satisfy a request by Sen. Barbara Mikulski (D-Md.) that NASA not scrap the mission without getting a second opinion. Mikulski wrote O'Keefe last week to say she was "shocked and surprised" by the decision and urged him to reconsider.
The two have spoken about the matter several times since then, according to O'Keefe, and the decision to ask Gehman to weigh in was made out of respect for the senator.
O'Keefe said he did not set a deadline for Gehman to report back, but that he would "expect a pretty expeditious answer." He also said that he has not reversed orders that the Hubble team wind down preparations for the servicing mission and transfer personnel to other activities.
Hubble scientists and engineers have said that the 14-year-old space telescope could last another three or three and a half years without the servicing mission. The purpose of the mission was to change out Hubble's failing gyroscopes and other components in order to improve the chances of the observatory staying in service at least until the James Webb Space Telescope is launched in 2011.
O'Keefe told reporters here that he is unlikely to change his judgement that sending a shuttle to Hubble is too risky, given the restrictions imposed on the shuttle program by the Gehman board in the aftermath of the Columbia disaster a year ago Feb. 1.
The Gehman board did not issue any recommendations that would specifically preclude a Hubble servicing mission, but did advise NASA to postpone any space shuttle mission not bound for the international space station until developing the means for a shuttle crew to inspect and repair any damage the might occur to the orbiter during launch.
NASA is working on the means to inspect and repair a shuttle docked to the station and has to have those capabilities in place in time to fly again this fall. O'Keefe said that even with on-board capabilities to inspect and repair a shuttle, the mission would still be much riskier than flying a shuttle to the station.
"In the end of the day its still a judgement call and my judgement is this is a real leap of faith," O'Keefe said.
Mikulski, meanwhile, is scheduled to speak to Hubble scientists and engineers at the Space Telescope Science Institute in Baltimore on Friday. She had planned to go there on Monday, but a winter storm that hit the East Coast prompted her to postpone her visit.
NASA asks Columbia inquiry expert for opinion on abandoning Hubble
WASHINGTON (AFP) Jan 29, 2004
NASA has asked the man who led the inquiry into the Columbia space shuttle tragedy his view on its decision to stop servicing the Hubble Space Telescope on safety grounds, NASA boss Sean O'Keefe said Thursday.
The National Aeronautics and Space Administration announced mid-January it was canceling the telescope's next servicing mission, scheduled for 2006, by shuttle astronauts.
NASA cited safety concerns and also budget problems for its decision that effectively condemns the Hubble to an early demise.
The telescope will remain in orbit as long as it can fulfill its duties, then be brought crashing back into Earth's atmosphere.
While a service mission would have allowed the Hubble to keep going beyond 2010, it could now stop working as early as 2007.
"We are dealing with a level of risk that's higher than on" the International Space Station (ISS), O'Keefe told journalists Thursday, to explain what he earlier described as the "painful decision."
The next mission to the Hubble would have required expensive shuttle safety updates that are not necessary on the ISS, the shuttle's only other job, NASA's chief scientist John Grunsfeld said late last week.
The updates were deemed necessary following the loss of the space shuttle Columbia, which disintegrated upon re-entry into the Earth's atmosphere in February 2003, killing all seven astronauts on board.
NASA's decision has provoked criticism among researchers and at Congress.
O'Keefe said Thursday that he was asking retired admiral Hal Gehman his view on NASA's decision in response to Democratic Senator Barbara Mikulski's request that he reconsider.
"I've asked admiral Gehman for his view -- not his judgment, not his analysis -- just his view," O'Keefe said, offering little hope, however, that he intends to go back on the decision.
NASA's announcement that it was dropping the Hubble came just days after President George W. Bush announced an ambitious space program to take US space travel back to the Moon to prepare the way for later missions to Mars.
NASA Firm on Hubble Decision but Would Listen to Options
By Robert Roy Britt
Senior Science Writer
posted: 10:46 am ET
04 February 2004
NASA is standing firm on its decision not to service the Hubble Space Telescope, but the agency would not ignore offers from other parties to extend the observatory's life providing someone else footed the bill and took responsibility for mission safety.
In a conference call with reporters today, the Associate Administrator for the NASA’s Office of Space Science, Ed Weiler, said he does not see anyone lining up to make such an offer, however.
Weiler also said that contrary to press reports, no serious layoffs of Hubble staff are planned. The agency's 2005 budget request includes money for continued operation of the telescope for the next few years, he said.
NASA announced in mid-January that Servicing Mission 4, slated for 2006, was cancelled because it could not reasonably meet new safety requirements set out by the Columbia Accident Investigation Board (CAIB).
Astronomers and even a senator called on NASA to reconsider. Despite NASA's insistence that the decision was entirely safety based, some saw it as the first casualty of the White House's new vision for expanded human spaceflight.
NASA chief Sean O'Keefe has since asked Retired U.S. Navy Adm. Harold Gehman, the chairman of the now disbanded CAIB, to evaluate the concerns and report back to him.
While from a science standpoint Weiler said today he would choose to keep Hubble going, he understands the safety-based decision not to send astronauts to work on the aging observatory.
Asked if NASA would consider an offer from someone to fund a servicing mission and take responsibility for safety, Weiler said, "I'm sure that NASA would listen to them." But he added: "I don't see anybody stepping up with a billion dollars."
Weiler said Hubble could remain operational at least through 2007 "and maybe 2008" if engineers are successful at conserving its batteries and figuring out how to point the telescope with two gyroscopes instead of three, as is now required.
Hubble currently has four working gyroscopes out of six. Several have been replaced in previous missions, the last time in 1999, and those still working will eventually fail.
Hubble is operated for NASA by the Space Telescope Science Institute (STScI) in Baltimore. STScI Director Steven Beckwith recently said he would consider all ways to keep Hubble going beyond its expected lifetime.
NASA, however, would have to approve any change in plans for Hubble.
"We have not pursued any avenues of asking for outside help," Beckwith said today. "We for the moment are working on ways to extend the lifetime of Hubble, working with NASA."
Beckwith made it clear that "we are not soliciting offers. When people make offers, we listen."
Hundreds of public pleas to keep the venerable observatory alive have rolled in to the STScI. Among the suggestions are asking the Russians to service the telescope. Others have asked if Hubble could be moved to the International Space Station.
"That ignores the laws of physics," Weiler said. Hubble is simply too heavy and in the wrong orbit to be maneuvered in that manner.
Others have suggested a robot might service Hubble. Weiler noted that astronauts have done "impossible things" to make previous servicing missions successful. "I frankly don't see how a robot could do the things an astronaut has to do," such as "closing doors that don't want to close."
Weiler, a scientist himself, is sympathetic with astronomers who bemoan O'Keefe's decision to let Hubble's mission wind down.
"Based on the science, we should do a Servicing Mission 4," Weiler said. "No question. Trouble is, there's more than science to be involved here." He cited astronaut safety in the wake of the Columbia shuttle disaster.
"I understand the things [O'Keefe] had to look at," Weiler said. "If I were in his position, I would have made exactly the same decision."
Weiler also allayed fears that the decision not to service Hubble would lead to immediate layoffs. President Bush's 2005 budget request leaves Hubble's operational budget intact.
Funding for daily operation of the telescope "has been untouched," Weiler said. The work force at NASA and the STScI will, however, be shifted to work on life-extension plans. "There are no massive layoffs planned" through 2005, he said.
Ultimately NASA must launch a robotic probe to capture and deorbit Hubble into the Pacific Ocean, a plan that has been in place since the telescope launched. It is too big to allow it to crash to Earth uncontrolled and risk hitting a populated area.
Weiler said some of the technology needed to carry that mission out still needs to be developed.
But there is no rush. Regardless of when Hubble stops being scientifically useful, it will remain safely in orbit until at least 2013, he said. The new budget allows $300 million over the next five years to plan for the deorbiting project. NASA has not decided in which year it will carry that mission out.
Meanwhile, the closest thing to a replacement for Hubble gained support in the new budget.
The James Web Space Telescope (JWST) is slated for launch in 2011. The infrared observatory will be powerful, but it will not record visible light, as does Hubble. Many astronomers have expressed a desire to keep Hubble going until 2011. And since JWST's development funding has not been entirely solid, they were also concerned its launch could be pushed back to 2012.
The JWST launch date is now "realistic" based on the new budget, Weiler said.
SpaceRef:
NASA Request for Information: Hubble Space Telescope End of Mission Alternatives
Synopsis - Feb 20, 2004
General Information
Solicitation Number: N-A
Posted Date: Feb 20, 2004
FedBizOpps Posted Date: Feb 20, 2004
Response Date: Mar 22, 2004
Classification Code: A -- Research and Development
Contracting Office Address NASA/Goddard Space Flight Center, Code 210.S, Greenbelt, MD 20771
Description THIS IS **NOT** A REQUEST FOR PROPOSAL, QUOTATION, OR INVITATION TO BID NOTICE.
NASA/GSFC is seeking methods and technologies at Technology Readiness Level 5 and higher to extend the useful scientific life of HST and to safely dispose of the observatory at the end of the HST mission. We are therefore requesting information from industry about approaches and techniques to accomplish both of these objectives. While our intent may be to team with industrial partner(s), we are not bound by this RFI to do so. It is neither a Request for Proposal, nor an Invitation to Bid, nor a Request for Quotation. Therefore, this RFI is not to be construed as a commitment by the Government to enter into a contract nor will the Government pay for information provided in response to this RFI.
The HST observatory operates in a low earth orbit at an approximate altitude of 568 Km. The HST science program executes around the clock, utilizing the full suite of HST scientific instruments. HST Servicing Mission 4, previously scheduled for launch in June 2006, has been cancelled. Further, HST retrieval by the Space Shuttle at the end of the HST mission is no longer an option.
NASA policy requires the safe disposal of HST. Current HST orbit decay models predict an uncontrolled HST re-entry no earlier than the year 2013. At present, the projected battery life is the principal limiting factor for overall observatory lifetime, and it is expected that the observatory will not be totally stationary in inertial space at the end of its life in orbit. NASA's plan is to maximize HST's scientific productivity through the remainder of the mission by extending its useful productive lifetime and sustaining its unique scientific capabilities as long as possible. Once the HST science program is no longer viable, the plan is to either de-orbit HST in a controlled manner or boost to a higher safe parking orbit (2,500 Km) utilizing a propulsion module that is to be attached to the spacecraft. In this scenario, the propulsion module will be launched on an expendable launch vehicle; rendezvous, capture, and dock with the HST; and provide for its controlled re-entry or boost to a higher safe parking orbit when required. There may be advantages to performing the de-orbit or orbit boost immediately after the completion of science operations, which could be as early as 2007 or 2008.
The objective of this RFI is: 1) to invite industry to submit information that will allow NASA to assess various design alternatives while formulating its detailed requirements for the re-entry or orbit boost mission; 2) to invite alternative mission concepts by which NASA may more fully accomplish its goal of maximizing HST science productivity; e.g., life extension approaches and techniques, with or without robotic servicing (which might simultaneously further objectives of NASA's new Exploration initiative); 3) to improve NASA's knowledge of industry's capability; and 4) to improve the overall understanding of current HST de-orbit or orbit boost mission plans.
NASA has posted certain information at ( http://hubble.gsfc.nasa.gov/end-of-mission.html ) in order to allow interested parties to learn more about the HST Program.
So as to consolidate our planning we request responses from industry within the next 30 days in the form of written and illustrated concepts, ideas, and descriptions of capability. We plan to invite formal presentations and discussions at GSFC of the more compelling responses within 45 days of the RFI issuance. Submission of responses may be via email. The subject line of the submission should be "HST End of Mission Alternatives RFI" and attachments should be in Microsoft WORD or PDF format. In the body of the email message please designate a point-of-contact and provide his or her name, address, telephone and fax numbers, and email address. The information is requested for planning purposes only, subject to FAR Clause 52.215-3, entitled "Solicitation for Information or Planning Purposes."
It is not NASA's intent to publicly disclose vendor proprietary information obtained during these discussions. To the full extent that it is protected pursuant to the Freedom of Information Act and other laws and regulations, information that is identified by a respondent as "Proprietary or Confidential" will be kept confidential.
It is the responsibility of industry to monitor the NASA Acquisition Internet Service for information concerning release of future solicitations.
SpaceRef...
Rep. Mark Udall Intorduces Resolution to Save Hubble Space Telescope
(Washington, D.C.) - Congressman Mark Udall (D-CO) today introduced a House resolution urging that an independent panel review NASA Administrator Sean O'Keefe's decision not to extend the life of the Hubble Space Telescope, thus condemning the Hubble to a premature death. The resolution also urges NASA to continue planning for Hubble's next servicing mission as NASA develops its inspection and repair capability, which will enable shuttles to fly both to the International Space Station and to the Hubble Space Telescope. Reps. Todd Akin (R-MO), Roscoe Bartlett (R-MD), Bart Gordon (D-TN), Steny Hoyer (D-MD), Nick Lampson (D-TX), Jim McDermott (D-WA), and C.A. Dutch Ruppersberger (D-MD) joined Rep. Udall as original cosponsors.
Rep. Udall stated: "My goal in introducing this resolution is simple - I want to call attention to the Hubble Space Telescope's contributions to scientific research and education and ensure that any decision affecting its future is made carefully and seriously and for the right reasons. Precisely because of Hubble's extraordinary contributions in the past and promised contributions in the future, I also believe it is important that the decision to cancel the planned servicing mission to Hubble be reviewed by an independent panel of experts and all options for safely carrying it out be examined.
"I also want to try to ensure that preparations for the servicing mission continue at least until the panel comes up with its recommendations and until NASA provides its timetable for complying with recommendations of the Columbia Accident Investigation Board report relating to on-orbit inspection and repair, since NASA's compliance will allow both a Hubble servicing mission and a mission to the International Space Station to be carried out safely.
"Hubble's scientific contributions continue to amaze us all, year in and year out. Hubble remains one of the most productive scientific instruments in history, and certainly NASA's most productive scientific mission, accounting for 35 percent of all its discoveries in the last 20 years.
"This resolution will be welcomed by scientists and interested citizens in this country and around the world who understand that Hubble is a national treasure that we should not abandon. The potential gains from extending Hubble's life are real and achievable - and I believe we should not arbitrarily cancel the servicing mission without exploring all options for safely carrying it out."
The text of the resolution is available at: http://www.house.gov/science_democrats/releases/udall_hubble_resolution_04mar03.pdf
Mr. Udall's statement introducing the bill can be found at: http://www.house.gov/science_democrats/releases/udall_hubble_statement_04mar03.pdf
Hubble Space Telescope Study Group Selected
By Leonard David
Senior Space Writer
posted: 06:30 pm ET
16 April 2004
A newly formed 20-person blue-ribbon panel that includes scientists, former astronauts, NASA managers, aerospace industrialists, a member of the Columbia Accident Investigation Board, and a robot expert will be taking a hard look at prolonging the mission of the Hubble Space Telescope (HST).
The study team is charged with independently evaluating what course of action can be taken regarding the fate of the famed orbiting observatory.
The National Academy of Sciences study is tagged "Assessment of Options for Extending the Life of the Hubble Space Telescope" and is to be completed under the auspices of the academy’s National Research Council and its Space Studies Board and Aeronautics and Space Engineering Board.
Louis Lanzerotti has been selected to chair the study group. He currently consults for Bell Laboratories, Lucent Technologies and is a distinguished professor for solar- terrestrial research at the New Jersey Institute of Technology.
Shuttle servicing option
The study group is taking on several items:
Consider issues of safety in using the space shuttle for HST servicing with an astronaut crew;
Look into the feasibility of robotic servicing approaches;
Assess the impacts of servicing options on the scientific capability of the HST, and;
Judge risk/benefit relationships between servicing options that are deemed acceptable.
The prestigious group is also charged to estimate to the extent possible the time and resources needed to overcome any unique technical or safety issues associated with HST servicing that are required to meet recommendations outlined by the Columbia Accident Investigation Board (CAIB), as well as an internal NASA study team, called the Stafford-Covey Return-to-Flight committee.
In addition, the panel is to assess the response of Hubble Space Telescope to likely component failures and the resulting impact on servicing feasibility, lost science, and the ability to safely dispose of HST at the end of its service life.
Innovative techniques
According to the study group’s statement of work provided to SPACE.com :
"NASA plans to continue operation of the HST until it can no longer support scientific investigations--currently anticipated to occur in the 2007-2008 time frame. The telescope's life may, in fact, be extended if NASA is successful in employing operational techniques to preserve battery and gyroscope functions. Meanwhile, NASA is investigating innovative ways to extend the science lifetime of the HST for as long as possible, including robotic servicing. Current plans are to safely de-orbit HST by means of a robotic spacecraft by approximately 2013."
One-gyro mode
The Hubble Space Telescope uses three gyroscopes to provide precision attitude control. They are required to make pinpoint observations of distant astronomical targets.
"There are currently four functional gyros on HST--three in operation plus one spare. Based on longevity experience with the gyros to date, it is likely that the system will be down to two operating gyros by about March 2006," points out the statement of work.
"The HST engineering team is currently working on approaches to sustaining useful astronomical operations with only two gyros, and they hope to have that capability by the time it becomes necessary. Two-gyro testing is slated to begin in March 2005, and there are hopes that even a one-gyro mode might be feasible for limited operations. The spacecraft can be held in a safe configuration with no operating gyros, but science operations would not be possible then," the statement of work observes.
While no deadline for the committee report is specified in the material provided to SPACE.com , it is noted that the panel will investigate the possibility of providing an interim report to NASA on a fast-track basis.
Hubble Space Telescope Study Group Members
Louis Lanzerotti, chair of the Hubble study group, consults for Bell Laboratories, Lucent Technologies and is a distinguished professor for solar- terrestrial research at the New Jersey Institute of Technology.
Steven Battel, a private consultant expert in space research and engineering;
Charles Bolden, Jr., former shuttle astronaut and now senior vice president at TechTrans International, Inc.;
Rodney Brooks, director of the Computer Science and Artificial Intelligence Laboratory at the Massachusetts Institute of Technology;
Jon Bryson, senior vice president at The Aerospace Corporation;
Benjamin Buchbinder, an expert in risk assessment;
Bert Bulkin, emeritus director of Scientific Space Programs at Lockheed Missiles and Space Company;
Robert Dunn, vice admiral, U.S. Navy (retired) and an independent aerospace consultant; Sandra Faber, professor of astronomy at the UCO/Lick Observatory, University of California, Santa Cruz;
Riccardo Giacconi, president of Associated Universities, Inc., and a research professor at Johns Hopkins University;
Gregory Harbaugh, a former shuttle astronaut and currently vice president and director of the Florida Air Museum;
Tommy Holloway, retired manager of the International Space Station Program Office for NASA's Johnson Space Center;
John Klineberg, former president of Space Systems/Loral;
Vijay Kumar, professor and deputy dean for research in the School of Engineering & Applied Sciences at the University of Pennsylvania;
Forrest McCartney, retired vice president for Launch Operations at Lockheed Martin Astronautics Cape Canaveral Air Station, Florida;
Stephen Rock, associate professor in the Department of Aeronautics and Astronautics at Stanford University;
Joseph Rothenberg, currently an independent consultant and former NASA associate administrator for Space Flight;
Joseph Taylor, Jr., the James S. McDonnell Distinguished University Professor of Physics and former dean of the faculty at Princeton University;
Roger Tetrault, recently served as a member of the Columbia Accident Investigation Board (CAIB); and
Richard Truly, director of the National Renewable Energy Laboratory and a past NASA administrator and former astronaut.
bisogna cercare un altro metodo di propusione! non dimenticate che ancora non si sa nulla dell'iterazione fra gravità e le altre forze come il magnetismo
Da Space.com (http://www.space.com/news/hubble_glitch_040807.html):
Hubble Trouble: One of Four Instruments Stops Working
By Robert Roy Britt
Senior Science Writer
posted: 07 August 2004
09:16 am ET
One of the four astronomical instruments on the Hubble Space Telescope shut down earlier this week and engineers are trying to pin down the problem. The other three instruments continue to operate normally.
The instrument, called the Space Telescope Imaging Spectrograph (STIS), does not make the classic pictures that Hubble is famous for, but instead splits light into its constituent colors. It has been used to discover dim stars that reveal clues about the age of the universe, study planet-forming environments around other stars and provide insight into black holes.
The STIS stopped working Tuesday, Aug. 3, going into what officials call a suspended mode, according to a NASA statement released Friday. Mission managers think there is a malfunction in a power converter. It is not known if the glitch can be fixed.
The spectrograph was installed during the second Hubble servicing mission, in 1997. It was designed to operate for five years. NASA says it has met or exceeded all its scientific requirements.
NASA has convened an Anomaly Review Board to investigate the problem and determine if the instrument is recoverable.
"A final decision on how to proceed is expected in the coming weeks as analysis of the problem progresses," according to the statement.
The instrument is not slated for replacement by the next servicing effort. That mission, which NASA Administrator Sean O'Keefe cancelled in January due to safety concerns for the space shuttle fleet, is up in the air right now. O'Keefe reconsidered his decision and said a robotic mission might be undertaken, though he continues to resist expert suggestions that a manned shuttle mission to service the telescope remain a serious option.
Hubble's other instruments -- the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), the Advanced Camera for Surveys, and the Wide Field/Planetary Camera 2 -- are not affected by the problem.
The STIS is used for about 30 percent of Hubble's observing time. A standby list of targets for the other three instruments will likely take up that time.
Hubble has otherwise been in good health. But its batteries and pointing gyroscopes are expected to fail in the next two to three years. If they are not replaced by a robotic or human servicing mission, Hubble will likely cease operations by 2008, engineers have concluded.
Da Space.com (http://www.space.com/news/hubble_mission_040810.html):
NASA Chief: 'Let's Go Save the Hubble'
By Robert Roy Britt
Senior Science Writer
posted: 10 August 2004
01:53 pm ET
Amid uncertainty over the fate of the Hubble Space Telescope and with a key instrument not working, NASA Administrator Sean O'Keefe gave the go-ahead Monday for planning a robotic servicing mission.
"Let's go save the Hubble," O'Keefe said. He did not say whether the failed instrument would be repaired.
O'Keefe told about 200 employees at NASA's Goddard Space Flight Center to develop a firm proposal within a year, at which time a decision would be made whether to proceed.
Costs not known
Al Diaz, NASA associate administrator for the agency’s Science Mission Directorate, would not say how much NASA expects the mission to cost.
NASA officials have stated previously that a full-fledged robotic servicing mission would likely cost in excess of $1 billion. A recent internal NASA study, according to government and industry sources, estimated the cost at $1.6 billion to $2.3 billion -- several times more than what NASA has spent in the past mounting space shuttle missions to the telescope.
It is not clear where the money would come from.
"That would have to be worked," NASA spokesperson Don Savage told SPACE.com Tuesday. The funding might involve a supplemental request to Congress or could come from shifting funds in NASA's existing budget, Savage said.
However, other sources, who did not wish to be identified, told Space News that NASA plans to ask Congress for supplemental funding when the lawmakers return to Washington in September.
Details of the robotic mission are still to be laid out. But in an encouraging sign for astronomers, O'Keefe asked engineers to consider a mission that would meet all of the objectives for a manned servicing mission that had originally been planned but was since canceled. That mission was designed to replace crucial parts and add two new instruments.
"He's thinking it's looking more and more like we ought to do full robotic servicing," Savage said.
Meanwhile, in a major blow to the Hubble program, prospects look dim for reviving an important instrument that stopped working last week. Its loss would leave a huge hole in astronomers' ability to study certain aspects of the universe, adding urgency to unsettled plans to service the observatory.
'Big loss'
The Space Telescope Imaging Spectrograph (STIS) conked out Aug. 3 when a power converter malfunctioned. People associated with the 14-year-old observatory said engineers were still trying to figure out whether the problem could be fixed remotely, but that early indications were a solution did not appear likely.
A spectrograph does not produce traditional pictures but instead analyzes light to discern a source's chemical compositions and temperature. STIS is the only spectrograph in space that records ultraviolet light, covering a range of the spectrum that can't be observed from Earth. The device made the only discovery of an atmosphere around another star. It has also studied black holes and provided confirmation of the age of the universe.
"It's a big loss," said Paul Scowen, a researcher at Arizona State University. "Without that a lot of science simply cannot be done now, until a new mission flies."
There are no firm plans for any such mission.
With colleagues, Scowen has proposed to NASA a future space-based observatory that would include a UV spectrograph, effectively replacing the STIS. It is one of nine competing proposals under the agency's Astronomical Search for Origins Program.
Scowen called the STIS second only to Hubble's Advanced Camera for Surveys (ACS) in importance to astronomers. The ACS and two other science instruments on Hubble continue to operate normally.
Partial replacement ready
The STIS was added to Hubble by shuttle astronauts in 1997. It was designed to last five years.
A partial replacement and complementary instrument, called the Cosmic Origins Spectrograph (COS), is built and was supposed to be installed during another servicing mission originally slated for last year. The mission was delayed by the Space Shuttle Columbia disaster on Feb. 1, 2003, and it was canceled by O'Keefe, NASA's chief, this January.
After a public, political and scientific outcry and accusations of back-room decision making, O'Keefe decided to consider a robotic mission to service Hubble. Its primary goals would be to replace the telescope's batteries and gyroscopes and to install a module that would eventually be used to safely de-orbit the observatory. If not serviced, Hubble would likely stop working altogether by 2008.
It has not been determined whether a robotic servicing mission could fix the vital STIS instrument or take on the daunting task of hooking up the phone-booth-sized COS.
Scowen is familiar with engineering discussions over the possible robotic servicing mission.
"Installing COS is a very tall pole right now," he told SPACE.com. "It is a proposal fraught with risk."
Astronaut John Grunsfeld, who has twice serviced Hubble and is now NASA's Chief Scientist, did much of the lobbying that led to O'Keefe considering a robotic mission. In an interview in May, Grunsfeld said swapping equipment robotically poses challenges. Astronauts can make adjustments if things get stuck, he said, but on the other hand "robots can do really pure motions."
Leaning toward robots
On July 13, a 20-member National Academy of Sciences commission suggested NASA Administrator Sean O'Keefe reconsider his ban on a crewed servicing mission.
The group's interim report on the matter cited limitations of robotics given the industry's infant stage. It pointed out that four previous crewed trips to Hubble were successful and said safety concerns do not preclude sending astronauts again. The panel urged NASA to commit to the original servicing mission, including installation of COS and another already-built camera called the Wide Field Camera 3 (WFC3), which would replace Hubble's Wide Field and Planetary Camera 2.
(Another of the nine proposals in the Astronomical Search for Origins Program would fly COS and WFC3 on a new observatory.)
O'Keefe praised the National Academies interim report but sidestepped any serious rethinking of his opposition to using astronauts. He has called such a mission too dangerous to ponder in the wake of the Space Shuttle Columbia disaster and subsequent investigations and recommendations made by the Columbia Accident Investigation Board.
While he hasn't ruled out a shuttle mission, a spokesperson said last month, O'Keefe is focusing on the robotic option.
"Everybody says, 'We want to save the Hubble' -- well, let's go save the Hubble," O'Keefe told The Orlando Sentinel after Monday's meeting with employees.
O'Keefe said it would take nine months to a year to formulate a solid mission plan from various proposals that NASA has been studying in recent weeks.
Fix STIS?
Engineers are probably a couple of weeks away from determining whether or not the power supply to the defunct STIS can be restarted from the ground. Importantly, the power unit was not designed to be serviceable, so any mission to the telescope -- robotic or human -- would face an as-yet undetermined project if officials decide to resurrect the STIS.
Savage, the NASA spokesperson, said it's too early to decide if a robotic mission could fix the STIS, as "engineers haven't been able to determine what caused it to fail." The possibility of repairing it would have to compete with other aspects of the robotic mission.
When asked if a manned shuttle mission to Hubble was still being considered, Savage said, "We're not doing anything to preclude doing that."
"Although it is too early to tell if STIS can be serviced, the astronauts have been remarkably versatile on previous missions for fixing instruments not designed to be serviced," Steven Beckwith, outgoing director of the Space Telescope Science Institute, which operates Hubble for NASA, said over the weekend.
In one example of astronaut capability, a shuttle mission in 2002 revived Hubble's infrared camera by installing a new cooling system.
Engineers have for months been testing robotic equipment for a possible automated effort, controlled from the ground, to repair or upgrade Hubble.
O'Keefe told employees Monday the robotic mission would cost up to $1.6 billion, according to press reports, but that a firm estimate could not be calculated until a final plan was developed.
It is not clear, however, if NASA will even get the basic funds it has asked for next year. Despite a White House-backed request for more money than last year, to support President Bush's vision of sending astronauts to the Moon and Mars, NASA's budget stands to be trimmed $229 million in the latest version in Congress.
Urgent need
If STIS is not fixed or replaced, one key loss will be the ability to examine atmospheres of extrasolar planets.
The spectrograph was used to discover and then characterize the atmosphere of HD 209458b, a planet orbiting a distant star. Astronomers termed it a shrinking lava-like world.
The compelling observations were possible only because HD 209458 transits directly in front of its host star, as seen from our vantagepoint. Astronomers expect as many as 10 similarly configured planets to found over the next five years, Beckwith said. "STIS will be the only way to analyze the atmospheres."
David Charbonneau, who worked on the team that probed HD 209458b, agrees.
"If the decision not to carry out the final servicing mission for Hubble is reconsidered, and if it is possible to repair the failed power supply, then of course this would be just fantastic," said Charbonneau, formerly at Caltech and now with the Harvard-Smithsonian Center for Astrophysics.
Charbonneau said the case for a Hubble repair mission was already compelling. The loss of the STIS has "made that discussion all the more urgent," he said via e-mail.
"It is a big task to weigh the unparalleled science that the Hubble Space Telescope can achieve with the risk and cost of a servicing mission, Charbonneau said, "but I certainly hope that the decision can be considered in much greater depth than has been presented to date."
OT
Chi mi sposta tutte le discussioni sullo spazio su Scienza?
Originariamente inviato da Athlon
ACK
Thanks dude... lo puoi fare anche con quelle che sono rimasti in Piazzetta? ;)
sono solo questi...
http://forum.hwupgrade.it/showthread.php?s=&threadid=603687
http://forum.hwupgrade.it/showthread.php?s=&threadid=622028
http://forum.hwupgrade.it/showthread.php?s=&threadid=612541
http://forum.hwupgrade.it/showthread.php?s=&postid=3378239
http://forum.hwupgrade.it/showthread.php?s=&postid=3420521
;)
Report: Shuttle servicing of Hubble is best option
NATIONAL ACADEMIES NEWS RELEASE
Posted: December 8, 2004
To ensure continuation of the extraordinary scientific output of the Hubble Space Telescope and to prepare for its eventual de-orbiting, NASA should send a space shuttle mission, not a robotic one, says a new congressionally requested report from the National Academies' National Research Council. The agency should consider launching the manned mission as early as possible after the space shuttle is deemed safe to fly again, because some of the telescope's components could degrade to the point where it would no longer be usable or could not be safely de-orbited, said the committee that wrote the report.
"A shuttle servicing mission is the best option for extending the life of the Hubble telescope and ultimately de-orbiting it safely," said committee chair Louis J. Lanzerotti, distinguished research professor at the New Jersey Institute of Technology, Newark, and consultant, Bell Laboratories, Lucent Technologies, Murray Hill, N.J. "NASA's current planned robotic mission is significantly more technologically risky, so a robotic mission should be pursued only for the eventual removal of the Hubble telescope from orbit, not for an attempt to upgrade it. Also, a shuttle mission could be used to place equipment on the telescope to make a robotic de-orbiting mission more feasible."
The Hubble telescope, which has operated continuously in orbit for the past 14 years, was designed to be serviced regularly by astronauts. Four servicing missions replaced nearly all the key components while increasing the telescope's capabilities. The fifth and final mission -- to replace aging batteries, fine-guidance sensors, gyroscopes, and two scientific instruments -- was originally intended to be completed by a shuttle crew as well, but NASA is currently planning an unmanned mission to service the telescope robotically.
The committee's principal concerns about a robotic mission are the risk of failing to develop it in time and the risk of a mission failure, as well as the possibility that the robot could critically damage the telescope. A robotic mission would face significant challenges in using its grapple system to perform autonomous close-proximity maneuvers and the final capture of the space telescope -- activities that have no precedent in the history of the space program and whose chances of success are low, according to the committee.
"Our detailed analyses showed that the proposed robotic mission involves a level of complexity that is inconsistent with the current 39-month development schedule," said Lanzerotti. "The design of such a mission, as well as the immaturity of the technology involved and the inability to respond to unforeseen failures, make it highly unlikely that NASA will be able to extend the scientific lifetime of the telescope through robotic servicing."
The committee assessed the safety risks of a shuttle servicing mission by comparing shuttle missions to the International Space Station -- to which NASA plans to send 25 to 30 more shuttle flights -- and shuttle missions to the Hubble telescope. The differences between the risks faced by the crew of a single shuttle mission to the space station and the risks faced by the crew of a mission to the Hubble telescope are very small, the committee concluded.
Also, a shuttle crew would be able to successfully carry out unforeseen repairs to the Hubble telescope and develop innovative procedures for unexpected challenges in orbit, the report notes. Such contingencies have been successfully addressed on three of the four prior missions to the telescope. A robotic mission, on the other hand, might not be able to repair failures that it is not designed to address, possibly stalling the mission in its early stages.
"With the replacement of aging components and the installation of new science instruments, Hubble is expected to generate as many new discoveries about stars, extra-solar planets, and the far reaches of the universe as it has already produced so far, with images 10 times more sensitive than ever before," Lanzerotti said.
The study was sponsored by NASA. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides science and technology advice under a congressional charter.
Brigante
16-05-2005, 15:44
Sembra proprio che il telescopio Hubble sia salvo.
Qui (http://punto-informatico.it/p.asp?i=52818&r=PI).
:read:
Star trek
16-05-2005, 18:52
menomale...
Beh, è pieno di errori quel pezzo, e cmq non è ancora deciso. Griffin ha semplicemente avviato lo studio per un'ultima servicing mission (SM-3) con lo Shuttle, decisivo per la conferma saranno il successo delle prossime missioni alla ISS (tutte le rimanenti ALMENO 25 missioni STS sono destinate alla ISS), e al piano finale (che potrebbe essere cambiato ancora, tanto per cambiare...) della finalizzazione della struttura della ISS.
La storia del budget poi è ridicola... Griffin vuole ridurre i costi per accelerare il programma CEV e così ridurre al minimo il gap tra il ritiro della flotta degli shuttle e la fine del programma STS (previsto per il 2010) e il primo lancio del CEV (previsto nel 2014). Vi saranno quindi sicuramente dei tagli ad alcuni programmi, soprattutto quelli scientifici, e Voyager non rientra in questo, ma in decisioni della passata gestione O'Keefe.
Non è ancora deciso nulla invece su un probabile rinvio della missione MSL.
Questo è l'articolo di SDC:
NASA Chief Pushes for Shuttle's Replacement
By Marcia Dunn
AP Aerospace Writer
posted: 13 May 2005
1:08 a.m. ET
CAPE CANAVERAL, Fla. (AP) -- NASA's new boss made an impassioned case Thursday for speeding up development of a new spacecraft so that the United States will not lose access to space when the shuttle is retired, but warned something else will have to be sacrificed.
Administrator Michael Griffin told a Senate subcommittee in Washington that to cover the cost of the shuttle replacement's accelerated debut, he may be forced to delay some space station and exploration research.
“We can't do everything on our plate, and we have to have priorities and first things first,'' he said.
Griffin wants to fly the proposed new spacecraft as soon as possible once the space shuttle fleet is retired in 2010 - avoiding a four-year gap in which the United States would have no way to launch astronauts.
The current plan, which he inherited when he took over NASA last month, calls for the new vehicle to carry a crew into orbit by 2014 and be capable of traveling to the moon and Mars, with modifications, in the years beyond.
Griffin said he finds that four-year launch gap unacceptable and hopes to have a plan for closing it by mid-July. The new crew exploration vehicle, or CEV, is a key part of President Bush's plan for returning astronauts to the moon by 2020.
“CEV needs to be safe, it needs to be simple, it needs to be soon,'' Griffin told reporters later in the afternoon.
The six-year gap between the 1975 Apollo-Soyuz mission and the 1981 debut of the shuttle damaged both the U.S. space program and the nation, Griffin said. “I don't want to do it again.''
“The United States of America should always have its own access to space,'' said Sen. Barbara Mikulski, D-Md.
Griffin told the Senate subcommittee on commerce, justice and science that he does not know how much it will cost to accelerate development of the crew exploration vehicle, still in the early design phase. But he said by choosing a single contractor in 2006, rather than having two contractors competing in flight in 2008 as envisioned by the former NASA administrator, $1 billion or more could be saved for use in the near term.
Additional money could be saved by putting off research at the international space station - such as experiments geared toward long-term moon stays or Mars habitation _ and possibly eliminating the handful of shuttle flights needed to fly that equipment, Griffin said. Eighteen shuttle missions are currently on the books to finish building the space station, along with 10 supply runs for a grand total of 28.
Right now, NASA's three remaining shuttles are grounded as the agency struggles to remedy all the safety concerns arising from the 2003 Columbia tragedy. Managers hope to launch Discovery on the first mission since the disaster in mid-July; repair work is going slow, though, and the schedule is tight.
Griffin assured the senators he would use a scalpel rather than a meat ax in cutting the research budget for the space station and other exploration systems, and would look at delaying projects not yet begun.
“Now the research ... is very valuable and it must be done,'' he said. “But if it is delayed a very few years in order to allow us to complete and affect a suitable transition between systems, then I believe that that delay would be worth it. And that would be where I would look for the money.''
Griffin pledged that NASA will complete the space station, currently just half built. But if the station still isn't finished when the shuttles are retired, the space agency may turn to unmanned rockets to haul up the remaining gear.
As for the Hubble Space Telescope, Griffin has ordered work to begin on one last shuttle servicing mission, with $291 million set aside in next year's budget. Whether that mission takes place will depend on the success of the next two shuttle missions.
Griffin's predecessor, Sean O'Keefe, ruled out Hubble visits by astronauts because of post-Columbia safety concerns.
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Questo è il 3D di discussione del forum di SDC:
http://uplink.space.com/showflat.php?Cat=&Board=missions&Number=216644&page=0&view=collapsed&sb=5&o=0&fpart
Prometheus, ISS Research Cuts Help Pay for Shuttle and Hubble Repair Bills
By Brian Berger
Space News Staff Writer
posted: 12 May 2005
11:02 a.m. ET
WASHINGTON -- NASA sent Congress a revised spending plan for 2005 that would significantly cut the Project Prometheus nuclear power and propulsion program, cancel a host of international space station-based biological and physical research activities, and postpone some space science missions, including two advanced space telescopes and a Mars science lander slated to launch in 2009.
The cuts were necessary, according to NASA, to pay the remaining $287 million tab for preparing the space shuttle for its return to flight, to make a substantial down payment on a potential Hubble Space Telescope servicing mission, to accommodate $400 million worth of special projects that lawmakers added to NASA’s budget last year, and to cover larger than predicted bills for a variety satellite projects being prepared for launch.
NASA informed Congress of these intended changes in an updated 2005 Operating Plan sent to Congress May 11. A copy of the operating plan, obtained by Space News, details changes both big and small that NASA says it needs to make to its $16.2 billion budget 2005 to get through the end of the fiscal year.
NASA’s latest operating plan includes the full $291 million Congress directed it to spend this year preparing for a possible Hubble servicing mission. NASA’s last spending plan, sent to Congress in December for review, allocated only $175 million of that amount to a Hubble mission. In February, NASA announced, to the chagrin of Hubble-supporters in Congress, that it would abandon any effort to save Hubble.
Since taking over as NASA administrator last month Mike Griffin has reversed that decision and ordered engineers at Goddard Space Flight Center to start preparing a Hubble servicing mission on the assumption that one will ultimately go forward. A formal decision is expected after the shuttle makes its return to flight.
Griffin explained his rationale in a May 10 letter accompanying the operating plan, saying that funding return to flight, Hubble servicing, programmatic overruns and releasing the $400 million in congressional earmarks “has created some difficult choices” for NASA.
“Given a choice, my preference as Administrator is to eliminate lower-priority programs rather than reducing all programs in the face of budget difficulties, to maintain efficient execution of the programs which remain,” Griffin wrote lawmakers. “Delays and deferrals inevitably lead to increased life cycle costs and erode the overall performance of the Agency's programs. Thus, NASA must set clear priorities to remain within the budget which has been allocated.”
Cut from NASA’s latest operating plan are about $160 million worth of space station-based biological and physical research efforts that a recently completed, although unreleased, NASA review concluded were unnecessary in light of NASA’s new focus using the space station for research that directly serves the needs of its space exploration goals.
While that is bad news for fundamental biological and physical research, some newly identified high priority areas of investigation will receive more money in the months and years ahead, according to Griffin.
“These high- priority areas include space radiation health and shielding, advanced environmental control and monitoring, advanced extra-vehicular activities, human health and countermeasures, advanced life support, exploration medical care, and space human factors,” Griffin wrote. “The highest priorities for research on ISS have been identified as medical research with human subjects and microgravity validation of environmental control and life support technologies. Lower-priority tasks, which are now subject to reduced funding, include basic research using model organisms (such as cells or rodents), and fundamental research in physics, material science, or basic combustion - with no direct link to exploration requirements.”
NASA also plans to refocus Project Prometheus on the development of “space-qualified nuclear systems to support human and robotic missions” especially those needed to support NASA’s near term exploration goals. NASA started the program known as Prometheus in 2002 to develop nuclear power and propulsion systems for deep space probes like the Jupiter Icy Moons Orbiter, a flagship-class mission that NASA deferred indefinitely earlier this year once it became clear that the undertaking would cost tens of billions of dollars and not necessarily help NASA accomplish its goal of returning to the Moon and sending humans to Mars.
The operating plan sent to Congress would cut $171 million from the Prometheus budget, leaving the program with $260 million for the time being.
Money for the Crew Exploration Vehicle, meanwhile, would remain untouched at $421.9 million for the year, even though NASA has said it intends to accelerate the program in order to minimize any gap between retiring the shuttle in 2010 and fielding the new system. NASA is still evaluating its options for accelerating the program, but has already announced that it intends to pick the contractor it wants to build the system in early 2006 instead of late 2008.
In addition to the cuts and increases, the operating plan also indicates that NASA intends to take planning for a Hubble servicing mission away from its Exploration Systems Mission Directorate and give it back to the Science Mission Directorate. Exploration Systems, however, picks up full responsibility for NASA’s nascent Lunar Robotic Exploration Program and the ISS Crew and Cargo Services effort to find alternatives to the space shuttle for delivering cargo and potentially people to the space station. That effort, initiated in 2004, had been under the management of the Space Operations Mission Directorate, which is in charge of the shuttle and station programs.
NASA would also delay the Space Interferometry Mission and Terrestrial Planet Finder, two advanced space telescope projects slated to launch some time after the James Webb Space Telescope. Griffin’s letter also says that NASA is considering delaying the Mars Science Laboratory mission from 2009 to 2011. NASA’s operating plan cuts nearly $72 million from the program.
Happy sweet 16, Hubble
http://www.spaceflightnow.com/news/n0604/24hubble16/hubble16.jpg
Credit: NASA, ESA and the Hubble Heritage Team (STScI)
Download larger image version here (http://www.spacetelescope.org/images/screen/heic0604a.jpg)
To celebrate the NASA-ESA Hubble Space Telescope's 16 years of success, the two space agencies are releasing this mosaic image of the magnificent starburst galaxy, Messier 82 (M82). It is the sharpest wide-angle view ever obtained of M82, a galaxy remarkable for its webs of shredded clouds and flame-like plumes of glowing hydrogen blasting out from its central regions.
Throughout the central region of Messier 82, young stars are being born 10 times faster than they are inside in our Milky Way Galaxy. These numerous hot new stars emit not only radiation but also particles called a stellar wind. Stellar winds streaming from these hot new stars also have combined to form a fierce galactic superwind. This superwind compresses enough gas to make millions more stars and blasts out towering plumes of hot ionised hydrogen gas, above and below the disk of the galaxy (seen in red in the image).
In M82 young stars are crammed into tiny but massive star clusters which themselves then congregate by the dozen to make the bright patches or "starburst clumps" seen in the central parts of M82. The individual clusters in the clumps can only be distinguished in the ultra-sharp Hubble images. Most of the pale objects sprinkled around the main body of M82 that look like fuzzy stars are actually star clusters about 20 light-years across and containing up to a million stars.
The rapid rate of star formation in this galaxy will eventually be self-limiting. When star formation becomes too vigorous, it will destroy the material needed to make more stars and the starburst will subside, probably in a few tens of millions of years.
Located 12 million light-years away, M82 appears high in the northern spring sky in the direction of the constellation Ursa Major, the Great Bear. It is also called the "Cigar Galaxy" because of the elongated elliptical shape produced by the tilt of its starry disk relative to our line of sight.
The observation was made in March 2006 with the Advanced Camera for Surveys' Wide Field Channel. Astronomers assembled this 6-image composite mosaic by combining exposures taken with four coloured filters that capture starlight from visible and infrared wavelengths as well as the light from the glowing hydrogen filaments.
Hubble was launched on April 24, 1990, aboard the space shuttle Discovery.
In its 16 years of viewing the sky, the NASA/ESA Hubble Space Telescope has taken roughly 750,000 exposures and probed about 24,000 celestial objects. Hubble does not travel to stars, planets and galaxies. It snaps pictures of them as it whirls around Earth. In its 16-year lifetime, the telescope has made nearly 93,500 trips around our planet, racking up almost 4 billion kilometres. That mileage is slightly more than a round trip to Saturn.
The telescope's observations have produced more than 27 terabytes of data, equal to roughly 400,000 compact discs. If those compact discs were stacked on top of each other, they would be nearly two times taller than the Eiffel Tower in Paris, France.
Each day the orbiting observatory generates about 10 gigabytes of data, enough information to fill up the hard drive of a typical home computer in a week.
In Hubble's 16-year lifetime, about 4,000 astronomers from all over the world have used the telescope to probe the universe.
Astronomers have published more than 6,300 scientific papers on Hubble results.
NASA Announces a new Servicing Mission to the Hubble Space Telescope
Servicing Mission 4 (SM4) is the final planned servicing mission for the Hubble Space Telescope. Astronauts will use the Space Shuttle to bring new instruments to Hubble along with gyros, batteries and other devices crucial for the telescope’s continued success through the year 2013. At the end of SM4, Hubble will be at the peak of its capabilities.
Evviva, finalmente alla NASA hanno capito quanto fosse importante!!!!!!
esatto!
SpaceFlightNow.com
'Go' for Hubble servicing mission
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: October 31, 2006
NASA Administrator Mike Griffin today reinstated a final shuttle mission to service and upgrade the Hubble Space Telescope, deciding the scientific value of the orbiting icon justifies the additional cost - and risk - of a stand-alone shuttle flight.
"We are going to add a shuttle servicing mission to the Hubble Space Telescope to the shuttle manifest before it is retired," Griffi told managers and engineers at the Goddard Space Flight Center in Greenbelt, Md.
Hubble Servicing Mission No. 4 - SM-4 - will be flown aboard the shuttle Discovery in May 2008. On board will be commander Scott Altman, pilot Greg C. Johnson, robot arm operator Megan McArthur and spacewalkers John Grunsfeld, making his third trip to Hubble, Mike Massimino, making his second, Andrew Feustel and Mike Good.
Altman served as commander of the most recent Hubble servicing mission, SM-3B, in 2002. Grunsfeld and Massimino participated in spacewalks during that mission and both are experts on Hubble servicing. The rest of the astronauts are making their first shuttle flight.
"What an exceptional day today is," said Sen. Barbara Mikulski, D-Md., a long-time Hubble supporter and instrumental advocate of a final servicing mission. "I'm so pleased and so excited that Dr. Griffin has just announced that Hubble will be serviced for the fifth time. ... It's a great day for science. It's a great day for discovery. It's a great day for inspiration, because that's one of the things Hubble has meant for so many people."
Five back-to-back spacewalks by Grunsfeld, Feustel, Massimino and Good, working in two-man teams, will be required to install six new batteries, a suite of six new gyroscopes, a powerful new camera, a state-of-the-art ultraviolet spectrograph and a refurbished fine guidance sensor to help the observatory find and track its targets.
The astronauts also will attempt to fix a broken imaging spectrometer, install a cooling system to lower its temperature, repair degraded thermal insulation and install a fixture that will permit the eventual attachment of a small rocket module to drop it safely out of orbit when it is no longer operational.
"We have conducted a detailed analysis of the performance and procedures necessary to carry out a successful Hubble repair mission over the course of the last three shuttle missions," Griffin said in a statement. "What we have learned has convinced us that we are able to conduct a safe and effective servicing mission to Hubble.
"While there is an inherent risk in all spaceflight activities, the desire to preserve a truly international asset like the Hubble Space Telescope makes doing this mission the right course of action."
If SM-4 is successful, engineers believe Hubble will remain scientifically productive through 2013 or longer, an additional three to five years beyond what could be expected based on the current health of its aging batteries and gyroscopes. With any luck at all, the telescope will still be operating when its replacement, the huge infrared-sensitive James Webb Space Telescope, is launched around 2013.
In the meantime, Hubble's two new science instruments will help the iconic observatory address some of the most fundamental questions in astrophysics and cosmology, including the nature of the so-called dark energy, believed to be accelerating the expansion of the universe, and the evolution of galaxies in the wake of the big bang.
Huge ground-based telescope using computer-controlled adaptive optics, which can compensate for turbulence in the atmosphere, rival or exceed Hubble's vision in some areas. But Hubble's resolution, "the sharpness of its vision, is really unparalleled and it will be a long while before that is achieved in the optical by the best adaptive optics," said Mario Livio, a senior astrophysicist at the Space Telescope Science Institute.
"There is some hope it will overlap with the James Webb Space Telescope, which in itself would be incredible. Imagine you would have something (in space observing) from the ultraviolet to the mid-to-far infrared, operating at the same time. This would be incredible."
When Columbia blasted off on Jan. 16, 2003, SM-4 was scheduled for takeoff in early 2005. But in January 2004, former Administrator Sean O'Keefe canceled the Hubble mission, arguing that an HST repair crew could not seek "safe haven" aboard the international space station in case of major problems with the shuttle that might prevent a safe re-entry. The two spacecraft circle the globe in very different orbits and shuttles cannot carry enough fuel to move from one to the other.
Without safe haven or certified techniques for fixing heat shield damage in orbit, O'Keefe said, a Hubble flight was too dangerous.
But Griffin said today the success of three post-Columbia missions proves NASA has dramatically lowered the risk of external tank foam insulation problems like those blamed for Columbia's demise.
Discovery will carry the same heat shield inspection boom and sensors that station flights carry, permitting the crew to inspect all critical areas on the shuttle before rendezvousing with Hubble and again, after Hubble is released. The inspection boom can carry an astronaut to any repair site on the shuttle and if impact damage is found, the crew will have improved repair materials and techniques at their disposal.
Flying in Hubble's orbit, the servicing crew will be exposed to a greater chance of micrometeoroid impacts than a station crew but that threat is offset somewhat by reduced risk in other areas.
Finally, NASA plans to process a second shuttle in parallel and to have it ready for launch on a rescue mission from a different pad within a week or so if Discovery suffers any sort of non-repairable damage. Providing additional margin, Discovery will be launched with enough on-board supplies to support the crew for at least 25 days in orbit.
"The astronaut office was not unified as to the opinion of whether we need a launch-on-need shuttle," Griffin said today. "Statistically, it would be silly to say anything other than we don't need a rescue mission because we have a much higher chance of losing a shuttle from some other cause for wich a rescue mission can't help you.
"But there is a small chance that we could lose a shuttle, an event which could be remedied by having a launch-on-need capability. To protect against that small chance, we have decided that we will maintain a rescue capability for this mission."
Said Mikulski, "Is going into space risk free? No. But our astronauts know that. ... They count on us to be as safe as possible. I will pledge to you today no matter what my role is on the appropriations, I will move heaven and Earth, this galaxy and even those unknown to make sure there is money in the budget to always protect our astronauts."
O'Keefe's cancellation of SM-4 in January 2004 touched off a storm on protest, prompting NASA to look into the feasibility of an robotic servicing mission.
The goals of the unmanned mission included the attachment of a propulsion module that could drive Hubble to a safe, targeted re-entry at the end of its useful life. But such a robotic flight ultimately was deemed too technically risky and too expensive.
With relatively minor exceptions, the goals of the currently envisioned shuttle mission are virtually unchanged from the flight O'Keefe cancelled. Five back-to-back spacewalks are planned:
EVA-1: Installation of three rate sensing units (six gyros) and one battery module (three batteries)
EVA-2: Installation of the Cosmic Origins Spectrograph and the second battery module
EVA-3: Installation of the Wide Field Camera 3 and insulation repairs
EVA-4: Space Telescope Imaging Spectrograph repair and installation of a cooling system
EVA-5: Installation of Fine Guidance Sensor No. 3 and associated equipment.
The Wide Field Camera 3, installed in place of the current Wide Field Planetary Camera 2, will provide high-resolution optical coverage from the near-infrared region of the spectrum to the ultraviolet
The Cosmic Origins Spectrograph, sensitive to ultraviolet wavelengths, will take the place of a no-longer-used instrument known as COSTAR that once was used to correct for the spherical aberration of Hubble's primary mirror. All current Hubble instruments are equipped with their own corrective optics
The refurbished fine guidance sensor, removed from Hubble during a 1999 servicing mission, will replace FGS-2R, which has a problem with an LED sensor in a star selector subsystem. Hubble uses three fine guidance sensors to locate and lock onto targets.
...
il resto dell'articolo all'indirizzo http://www.spaceflightnow.com/shuttle/sts125/061031approval/
Sono molto contento del prolungamento di vita di questo fenomeno.
Piuttosto, non sarebbe meglio cambiare titolo alla discussione? ;)
Così com'è è un pò ingannevole....
Piuttosto, non sarebbe meglio cambiare titolo alla discussione? ;)
Così com'è è un pò ingannevole....
Avevo cambiato il titolo del primo post, ma quello che si vede come titolo del thread purtroppo non si può cambiare dal momento in cui viene scritta una risposta... per cambiare il titolo ci vuole un mod... chiederò a Cristina.
;)
che risoluzione puo' vantare il sensore di presa principale dell'hubble? (non mi ricordo se sia stato mai oggetto di riparazioni/sostituzioni/miglioramenti)
p.s. so che dare definizione di risoluzione riferita magari oggetti distanti centinaia di anni luce non e' cosi' agevole, ma e' solo per farmi un'idea..
mmh non so cosa tu intenda per sensore di presa principale, Hubble ha quattro camere, la più grande delle quali è la WFPC2 (Wilde Field and Planetary Camera 2 (http://en.wikipedia.org/wiki/WFPC2), che verrà sostituita dalla 3 durante l'HSM-4).
Maggiori informazioni su Hubble qui:
http://www.nasa.gov/mission_pages/hubble/spacecraft/index.html
http://hubblesite.org/
http://en.wikipedia.org/wiki/Hubble_space_telescope
sorry, mi riferivo alla WFPC2 che non ricordavo fosse l'acronimo di Wide Field Planetary Camera 2 :fagiano:
dal momento che verra' sostituita l'hubble ricevera' quindi anche un upgrade anche in termini di megapixels..con un auspicabile aumento della qualita' e nitidezza delle immagini..
bloccatemi se sbaglio! :D
edit: mi sono anche dato una risposta sulla "risoluzione" dell'hubble
http://hubblesite.org/the_telescope/nuts_.and._bolts/res101.shtml ;)
(tnx Gio per i links)
fermarmarsi ai megpixl in queste camere è riduttivo...
cambia in maniera drastica piu che altro la sensibilità...
fermarmarsi ai megpixl in queste camere è riduttivo...
cambia in maniera drastica piu che altro la sensibilità...
certo, era solo per metterla in maniera piu' "consumistica". ci sarebbe anche da dire parecchio sulla gamma di frequenze che questo apparecchio riesce a catturare. ;)
Grande GioFX, sei riuscito a cambiare il titolo!!!!!! :D
X la gamma di frequenze:
lo STIS opera tra la lunghezza d'onda dell'ultravioletto (115 nm) e quella del vicino infrarosso (1000 nm), mentre il NICMOS riesce a lavorare in una lunghezza d'onda compresa tra 0,8 e 2,5 micron....
Grande GioFX, sei riuscito a cambiare il titolo!!!!!! :D
Ringraziamo ChristinaAemiliana... ;)
duchetto
09-11-2006, 09:55
Spitzer and Hubble create colorful masterpiece
NASA's Spitzer and Hubble Space Telescopes have teamed up to expose the chaos that baby stars are creating 1,500 light-years away in a cosmic cloud called the Orion nebula.
This striking infrared and visible-light composite indicates that four monstrously massive stars at the center of the cloud may be the main culprits in the familiar Orion constellation. The stars are collectively called the "Trapezium." Their community can be identified as the yellow smudge near the center of the image.
Swirls of green in Hubble's ultraviolet and visible-light view reveal hydrogen and sulfur gas that have been heated and ionized by intense ultraviolet radiation from the Trapezium's stars. Meanwhile, Spitzer's infrared view exposes carbon-rich molecules called polycyclic aromatic hydrocarbons in the cloud. These organic molecules have been illuminated by the Trapezium's stars, and are shown in the composite as wisps of red and orange. On Earth, polycyclic aromatic hydrocarbons are found on burnt toast and in automobile exhaust.
Together, the telescopes expose the stars in Orion as a rainbow of dots sprinkled throughout the image. Orange-yellow dots revealed by Spitzer are actually infant stars deeply embedded in a cocoon of dust and gas. Hubble showed less embedded stars as specks of green, and foreground stars as blue spots.
Stellar winds from clusters of newborn stars scattered throughout the cloud etched all of the well-defined ridges and cavities in Orion. The large cavity near the right of the image was most likely carved by winds from the Trapezium's stars.
Located 1,500 light-years away from Earth, the Orion nebula is the brightest spot in the sword of the Orion, or the "Hunter" constellation. The cosmic cloud is also our closest massive star-formation factory, and astronomers believe it contains more than 1,000 young stars.
The Orion constellation is a familiar sight in the fall and winter night sky in the northern hemisphere. The nebula is invisible to the unaided eye, but can be resolved with binoculars or small telescopes.
This image is a false-color composite where light detected at wavelengths of 0.43, 0.50, and 0.53 microns is blue. Light at wavelengths of 0.6, 0.65, and 0.91 microns is green. Light at 3.6 microns is orange, and 8.0 microns is red.
http://www.spaceflightnow.com/news/n0611/08masterpiece/masterpiece.jpg (http://photojournal.jpl.nasa.gov/jpeg/PIA01322.jpg)
Da SpaceFlightNow.com: http://www.spaceflightnow.com/shuttle/sts125/080929hubble/
Failure aboard Hubble could change shuttle plans
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: September 29, 2008
A science data control system aboard the Hubble Space Telescope failed Saturday, preventing the observatory from relaying data to the ground and effectively ending science operations until the observatory can be switched over to a backup unit late this week.
The backup control unit/science data formatter, or CU/SDF-B, has not been powered up since the telescope was launched in 1990. Even if it works - and if multiple subsystems successfully make the transition - NASA would still be faced with a loss of redundancy in a critical system and a subsequent failure in the B-channel electronics would permanently disable the observatory. As a result, sources say, launch of the shuttle Atlantis on Oct. 14 on a long-awaited mission to service the space telescope likely will slip to early next year if senior managers decide to replace the CU/SDF-A electronics box.
Shuttle mission STS-125, the fifth and final Hubble servicing mission, already has a full plate: five back-to-back spacewalks are planned to install two new science instruments, to repair two others, to install six new gyroscopes, six new batteries, a new fine guidance sensor and new insulation blankets. It is considered one of the most challenging Hubble servicing missions yet attempted.
A spare control unit/science data formatter, used for testing and troubleshooting, is available at the Goddard Space Flight Center in Greenbelt, Md., but it has not been powered on since 2001 and it would require extensive testing and checkout to upgrade it to flight status. Whether the unit could be added to Atlantis' payload complement without bumping something else is not yet known.
Likewise, it's not yet known when Atlantis could be ready for launch if a replacement is ordered. But sources said today the flight likely would slip to January or February, throwing a wrench of sorts into NASA's tightly scripted space station assembly schedule.
If the Hubble flight is, in fact, delayed to next year, NASA likely would press ahead with plans to launch the shuttle Endeavour around Nov. 16 on a space station assembly mission. Endeavour already is mounted atop pad 39B to serve as a quick-response rescue vehicle for Atlantis should the Hubble crew encounter any orbiter problems that might prevent a safe re-entry. It's not yet clear, however, which pad Endeavour would use if the Hubble flight is delayed.
Either way, the shuttle Discovery, now scheduled for launch Feb. 12 on a mission to deliver a final set of solar arrays to the station, would have to replace Endeavour as a rescue vehicle for Atlantis.
In the meantime, NASA managers have postponed a planned executive-level flight readiness review for Atlantis and mission STS-125. A media teleconference to discuss the Hubble failure and possible shuttle launch scenarios is expected later today.
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Da NasaSpaceFlight.com: http://www.nasaspaceflight.com/2008/09/hubble-control-system-failure-threatens-sts-125-launch-date/
Hubble control system failure - Threatens STS-125 launch date
September 29th, 2008 by Chris Bergin
A major failure of the “Side A” control system on the Hubble Space Telescope may delay STS-125’s launch to 2009 - should managers decide to send up a replacement unit, or if a mitigation plan fails to restore the Telescope’s functionality.
The failure has shut down Hubble’s science operations, and is currently unable to send data back to Earth. Attempts will be made to switch to the “Side B” control system later this week.
Switching over to the Side B control system has never been attempted in the lifetime of the telescope, although it is hoped the process will work, and return Hubble back to functionality.
“Side A of the CUSDF (Control Unit/Science Data Formatter) in HST went into safe hold, this means science operations have stopped. The spacecraft is still operational but unable to operate the instruments,” noted information acquired by L2.
“Attempts to recover the A side have failed so the project is now working to transfer science operations to the B side, this requires transferring the whole spacecraft from Side A to Side B so its a significant operation.
“Side B side has not been operated on orbit, for HST’s entire on orbit service life it has operated on Side A. However, the B side was fully tested before launch.
“The plan as of now is to complete the transfer to the B side later this week. The details for this will be provided later by the project.
“If the B side comes up fine we could still launch on time so I propose that we do not postpone the (Agency) FRR (Flight Readiness Review) at this time.
“If the B side does not come on line then we clearly have no mission as there is no way to get science data down. ”
Evaluations are taking place on whether a replacement control system - to return redundancy to the telescope - will now be required to launch with STS-125. If this becomes the case, the mission would have to wait until the replacement part has been tested and sent to the Kennedy Space Center (KSC).
This would delay STS-125 until 2009.
Optional plans - in the event Hubble’s problem will result in a delay to STS-125 - are being drawn up. This includes launching Endeavour on STS-126 in November, and Atlantis to Hubble in February.
“Options are in work. Earlier we had a plan to launch STS-126 first in November and follow up with HST in Feb. with the Feb. 2009 flight as back-up,” added one response to the memo.
“We will dust off our plans and see what we can do.”
Da SpaceFlightNow.com: http://www.spaceflightnow.com/shuttle/sts125/081017hubble/
New Hubble trouble stalls telescope reactivation
http://spaceflightnow.com/news/images/ni0810/17hubble_400.jpg
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: October 17, 2008;
Updated after news conference
Work to switch the Hubble Space Telescope to a backup science data management system after a component failed last month has been interrupted by a pair of on-board glitches during the restart process, officials said today. Engineers do not yet know if the anomalies are related, whether any actual hardware failures are involved or even whether the data management reconfiguration played a role. But they are hopeful analysis of telemetry and computer logs will help them resolve the issue and resume normal science operations.
"The operations team is working diligently to understand the cause and options for proceeding," said Jon Morse, director of the astrophysics division at NASA headquarters. "We remain optimistic at this time for recovering full science operations. But even the best laid plans can encounter some unanticipated difficulties."
The original failure occurred Sept. 27 as NASA was preparing to launch the shuttle Atlantis Oct. 14 on a long-awaited servicing mission. Channel A of the telescope's control unit science data formatter, or CU/SDF-A, began acting erratically and the telescope's main flight computer, following pre-programmed instructions, "safed" the payload computer and science instruments.
An attempt by ground controllers to reset the formatter was not successful and engineers quickly determined the box had suffered a "hard" failure. With the formatter out of action, data from Hubble's operational science instruments could not be relayed to the ground.
The shuttle flight was delayed to mid February at the earliest to give engineers time to flight qualify a spare science instrument control and data handling system, a box that contains both A- and B-side electronics. In the meantime, engineers at the Goddard Space Flight Center in Greenbelt, Md., decided to switch Hubble over to its current B-side data management system to restore science operations. Those components have not been powered up since launch in 1990.
The switchover began Wednesday. Telemetry from the telescope indicated the initial transition went smoothly. Wednesday night, engineers turned on the B-side science instrument control and data handling system, which includes the B-side data formatter. They then confirmed the Wide Field Planetary Camera 2, the one operational channel of the Advanced Camera for Surveys and the Near Infrared Camera and Multi-Object Spectrometer, or NICMOS, were able to communicate with the B-side SI C&DH system. The instruments then were put back in safe mode pending commands to switch control to the SIC&DH.
Thursday, engineers tried to bring the science instruments back on line. That's when the first of two problems developed.
"On Wednesday, engineers at the Goddard Space Flight Center reconfigured six components of the Hubble data management system and five components in the science instrument command and data handling system to use their redundant, or what we sometimes call the B side," said Art Whipple, manager of the Hubble Systems Management Office at Goddard. "This work was to work around a failure that occurred on Sept. 27 in the side-A science data formatter, which is a part of that SIC&DH system. It resulted in a cessation of all science observations except for astrometry, which are done with the fine guidance sensors that don't go through the SIC&DH.
"The reconfiguration proceeded nominally and the Hubble resumed the science timeline at noon Eastern time on Thursday. The first activities out of that onboard science timeline were the commanding of the science instruments from their 'safe' to 'operate' mode. This occurred nominally for the Wide Field Planetary Camera 2 and for the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). However, an anomaly occurred during the last steps of the commanding to the Advanced Camera for Surveys."
The Advanced Camera for Surveys, installed in 2002, suffered an earlier failure that knocked out its visible light wide-field and high-resolution cameras. Only its solar blind channel, which is sensitive to ultraviolet light, is still in operation. The Atlantis astronauts hope to repair the ACS during the upcoming servicing mission.
"At 1:30 p.m. Eastern (Thursday), when the low-voltage power supply to the ACS solar blind channel was commanded on, software that was running in the microprocessor in ACS detected an incorrect voltage level in the SBC and suspended ACS," Whipple said. "Then, at 5:14 p.m., the Hubble spacecraft computer, the 486, sensed the loss of a keep-alive signal from the NASA standard spacecraft computer in the C&DH and correctly responded by safing the SIC&DH and the science instruments.
"At this time, it's not known if these two events were related. The investigation into both anomalies is underway. All the data's been collected and it's being analyzed here at Goddard. The science instruments will remain in safe mode until the SIC&DH issue is resolved. All other systems on the spacecraft are performing nominally."
Asked if the telemetry had shed any light on what sort of problem - hardware failure, commanding error or some sort of misconfiguration - might be responsible, Whipple said "we're in the early stages of going through a mountain of data that has been downloaded over the last 24 hours."
"At this point, we are fairly certain, although nothing's been 100 percent ruled out, but we're fairly certain it is not a configuration or a commanding error," he said. "We are not to the point where we can rule out either transient issues or, for that matter, hard failure. We're just not there yet."
The initial fault in the Advanced Camera for Surveys occurred when a computer inside the instrument failed to detect the required 8 volts from the low-voltage power supply. Several hours later, the 486 flight computer, which constantly monitors the status of the payload computer, detected an apparently loss of keep-alive power in the B-side SIC&DH computer.
Whipple said the actual transition to Hubble's B-side science data management system went smoothly, with no apparent problems.
"There really are no changes that we're seeing in any of our other telemetry," he said. "The behavior of those six data management system components we switched over has been absolutely perfect so far."
But, he added, "we changed a number of things in the configuration of the spacecraft. It was not unexpected that there might be issues. This is, in fact, one of the contingency cases we thought a great deal about ahead of time and we're not totally unprepared for. ... We expect we will work through it, we will be back up and doing science between now and the servicing mission. The team is doing well. I can't tell you they'll get the entire weekend off, but we're cognizant of the fact that this is a marathon, not a sprint. It's important that we do things right, rather than fast."
Problemi col "pezzo di ricambio" disponibile che sembra non funzionare (http://www.nasaspaceflight.com/2008/10/atlantis-de-stack-hst-spare-hardware/) a dovere, per ora è indicato il periodo tra Aprile e Maggio come nuova data di lancio:
The problem relates to the replacement ground unit that needs to be delivered to the Kennedy Space Center (KSC) for flight with Atlantis, following the recent failure to the SIC&DH (Science Instrument Command and Data Handling) system Side A, which has since been switched over to its redundant Side B.
This replacement unit - a spare at the Goddard Space Flight Center (GSFC) - was rumored to be “faulty” for some time now, despite denials from HST engineers. However, official notes show that testing on the unit has resulted in “bad news”.
“Good news on orbit: HST team has swapped strings on the problematic box and HST is now on Side B for its command and data system, except for the network interface box. That box failed on Side B and was cross-strapped to Side A,” noted a management memo on L2.
“Bad news on the ground: Started testing boxes and had a failure on Side A. These failures probably take the February or March launch opportunity off the table. STS-125 (HST SM4) may launch mid-April to May.”
There have been no notes of a delay past May, which would in turn cause extreme problems for the Constellation program - which is already suffering a hit to their Ares I-X test flight schedule, which requires Pad 39B to be modified. This can not take place until the standdown of the STS-400(1) rescue mission that supports STS-125.
The two dates being looked at relate to April 17 or May 12 - though no dates will be set until the November 5 meeting, given the SSP (Space Shuttle Program) - headed by shuttle manager John Shannon - set the launch dates. That meeting will likely realign the next several flights - which will include orbiter swaps - to optimize the schedule.
A ‘tentative’ plan is being put together for the de-stack of STS-125. Should this plan be approved by the management team, pre-ops for S0030 will begin on Monday, with Atlantis heading back to OPF (Orbiter Processing Facility) Bay-1 later next week.
Calendario (http://www.boston.com/bigpicture/2008/12/hubble_space_telescope_advent.html) di dicembre a tema Hubble:
http://cache.boston.com/universal/bigpicture/10_506b.jpg
http://cache.boston.com/universal/bigpicture/13_200716.jpg
Giove e Ganimede (http://www.planetary.org/blog/article/00001778/) (in colori naturali):
http://www.planetary.org/image/hs-2008-42-c-xlarge_web.jpg
Da notare che questa foto non è stata fatta "perchè bella", ma per un motivo più scientifico:
I propose to observe a disappearance of Ganymede behind the dark limb of Jupiter with five filters of the ACS/HRC camera. Two exposures in each filter can be taken during such an event. The images will provide the spectral variation of the altitude of the apparent limb of Jupiter. The altitude of the apparent limb is dependent on the presence of hazes in Jupiter's stratosphere. Hazes of vertical optical depths below 0.001 could be detected with these observations, providing an extremely sensitive probe of high hazes. The observations probe altitudes levels near the 1-mb pressure level, for which we have very limited data.
The creation of aerosols, their growth, and their transport by winds is currently a mostly theoretical study. It would significantly benefit from constraints derived from the proposed observations. ACS/HRC is the only instrument capable of the required spatial resolution in the ultraviolet. Furthermore, a favorable geometry of Ganymede's orbit occurs only once every six years. This proposal achieves unique results with a minimum of HST time.
In other words, he's using the brightly reflective surface of icy Ganymede as a light source, shining from behind as it sets behind Jupiter, to illuminate hazes high in Jupiter's atmosphere, above those visible clouds. The fact that the images captured for this study were also very pretty was just a happy by-product.
SFN:
http://www.spaceflightnow.com/news/images/ni0905/09hubble_400.jpg
The history of Hubble:
A grand space telescope
The Hubble Space Telescope has cost U.S. taxpayers some $10 billion in the quarter century since the project was approved. But to astronomers around the world, the high-flying satellite is, in a word, priceless.
http://www.spaceflightnow.com/shuttle/sts125/090509history/
Paganetor
11-05-2009, 13:42
stasera parte uno shuttle con i pezzi nuovi per aggiustare/migliorare l'Hubble!
mitico! :D
ma i nuovi strumenti che permetteranno di fare ad hubble che prima non poteva???
ma i nuovi strumenti che permetteranno di fare ad hubble che prima non poteva???
Una parte della missione è dedicata alla "manutenzione":
- ACS (Advanced Camera for Surveys) e STIS (Space Telescope Imaging Spectrograph) verranno riparati in orbita e quindi non avranno nuove funzioni.
- Verranno sostituite le batterie, i giroscopi/RSU, un "fine guidance sensor" e il "science instrument command and data handling system computer" per prolungare la vita di Hubble.
inoltre verranno installati due nuovi strumenti:
- Wide Field Camera 3 (WFC3): è più sensibile e più veloce (semplificando :D). Permetterà di proseguire e migliorare gli studi sull'energia oscura.
WFC3 is the first panchromatic instrument built for Hubble, a wide-field camera with a wide spectral range that will open new windows on the universe and, at the same time, restore lost visual performance due to radiation damage in other detectors. In the near ultraviolet, WFC3 will boost discovery efficiency by 40 percent while the near infrared detector will allow much faster surveys.
"The thing WFC3 has that's particularly exciting is sensitivity into the near infrared," Margon said. "The reason that's important is, once again, the red shift. If you want to look at the distant universe, it gets redder and redder as you look farther and farther away. Hubble is a general purpose telescope, it will look at everything, planets, stars, galaxies, all that. But the problem that probably excites people the most right now is this issue of the dark energy, which is accelerating the expansion of the universe. And that's a problem that didn't exist when Hubble was launched.
"The status of this dark energy now is, everybody agrees it's there, which is itself pretty astonishing, and that the dark energy that is responsible for accelerating the expansion is actually 75 percent of the matter/energy budget of the universe. So not only is it there, but it's the overwhelming form of stuff, even though (10) years ago we had not even a glimmer that it existed."
Hubble has played a major role in the ongoing search for answers, by finding distant Type 1A supernovas, stellar explosions thought to occur when a compact white dwarf in a binary star system accumulates enough mass from its companion to reach a critical density. At that point, the quantum mechanical property that had been resisting the inward crush of gravity is overwhelmed, triggering a catastrophic collapse and explosion.
Because the explosions occur at the same mathematical point - the moment the star's mass exceeds roughly 1.44 times that of the sun - astronomers believe their energy output is roughly the same. Thus, the light output of a Type 1A supernova can be used as a so-called "standard candle," a mileage marker, in effect, that can be used to determine the distance to objects farther back in space and time than otherwise possible.
The apparent brightness of an object drops off with distance from the observer in a precise way and observations in the late 1990s showed Type 1A supernovas in remote galaxies were dimmer than expected. The most obvious explanation, assuming the supernovas really do behave like standard candles, was that the universe had expanded more - and that the supernovas were more distant - than would be expected if the cosmic expansion was slowing down.
Astronomers believe the dark energy driving that acceleration has been present since the big bang, but it was overshadowed by gravity through the first five billion years or so of the cosmic expansion. But as the universe thinned out and its density dropped, dark energy began reversing what to that point had been a gravity-driven deceleration. And so, the universe began accelerating and flying apart faster and faster.
Hubble has found the most distant Type 1A supernovas, helping scientists confirm the idea of dark energy. The problem is, Margon said, "nobody knows what it is, nobody has any clue as to why it's there, what its form is, it's just there. The next thing you want to ask is what the hell is it? Is it Einstein's cosmological constant, is it something else?"
"It turns out, an extremely sensitive test of what form the dark energy is in is to just ask how does this 'oomph' change with cosmic time? How does its importance change with cosmic time? And Einstein's cosmological constant, this repulsive gravity, it doesn't change at all with cosmic time. But if, for example, we're part of a multi-dimensional universe and there are other dimensions pushing on us and stuff like that, those things change with cosmic time.
"So the way you can actually probe that, of course, is to simply look backwards and look at distant objects, because then you're testing the geometry of the universe in the past. And if you ask how far back do I need to look to start to make a difference amongst the different ideas about what dark energy is, it turns out to be a red shift that corresponds very, very nicely to the reddest sensitivity of Wide Field Camera 3. Mostly by good luck, I've got to say!
"So if you can just continue to map out the deviations from the Hubble diagram (classical expansion) of very distant galaxies out in the reddest band where Wide Field 3 works, you should be able to differentiate between models of the dark energy. ... That, I think, is really exciting."
- Cosmic Origins Spectrograph (COS): è dalle 10 alle 20 volte più sensibile di STIS nella spettrocopia a media e alta risoluzione. Verrà utilizzato per studiare la struttura a grande scala dell'universo, il medium interstellare e intergalattico e la formazione di stelle e pianeti.
COS was designed to study the large-scale structure of the universe, the intergalactic medium, the origin of the elements, the formation and evolution of galaxies, the interstellar medium and the formation of stars and planets.
"We now understand that the universe has sort of three slices of the pie," Margon said. "There's dark energy, which is about 75 percent. There's dark matter, which is about 20 percent. And then there are atoms (of normal matter), which is just about 5 percent. But something that there have been glimmers of for about 50 years and now we're finally quite certain of, is that in the atoms-we-know category, most of them are not contained in stars and galaxies, but are rather contained in a very dilute gas in between galaxies.
"The original naive picture of the way the universe was put together was that galaxies were the building blocks and in between galaxies there was essentially a perfect vacuum. Gradually, creeping up over 50 years, the picture is actually reversed. It turn out that probably more than 50 percent of all normal atoms are between galaxies, rather than inside them. Which, of course, continues to drive the Earth, sun and things we know to more of a footnote."
So how does one study the intergalactic medium, or IGM? By looking at distant objects like quasars and figuring out how that light was affected by its passage through the IGM on its way to Earth.
While COS is a general purpose instrument and will be used by astronomers to study a variety of targets, "sort of the motivating design problem was to look at very distant quasars, just as background targets, and your line of sight to them will have to traverse a huge number of these atoms in the intergalactic medium," Margon said.
"It turns out that given the conditions in the intergalactic medium, the only place they will interfere with light from those distant quasars is in the ultraviolet. ... The critical diagnostics cannot be reached from ground-based telescopes. And again, because you need to observe in the UV, there's no future clever technological development from ground-based telescopes that will overcome that. Nobody's going to invent some device to observe light that doesn't arrive.
"So characterizing the state of this intergalactic medium, where most atoms reside, is kind of the father problem for the Cosmic Origins Spectrograph. That's why it's called 'cosmic origins.' Because that dilute medium is the medium out of which galaxies and stars eventually collapsed. But it turns out what has been left behind is, in fact, the majority of the atoms in the universe. It's probably 90 percent hydrogen and 10 percent helium. Everything else, with the exception of just very trace amounts of lithium and deuterium have been built up later in stars."
It is not yet clear how uniform the IGM might be - the degree to which it is lumpy, filamentary or smoothly distributed - but COS may help find the answer.
"As we see absorptions, as we see interference in the spectra of background objects caused by the intergalactic medium, those pieces of matter will have characteristic red shifts depending on how far away they are," Margon said. "And so COS will take these ultraviolet spectra of very distant objects and will ask, are there discrete interruptions of the spectra that correspond to discrete red shifts, in which case it would be very lumpy. Or are there just kind of absorptions everywhere through the spectrum, in which case it might be more uniform. Nobody really knows."
But the answer, Margon said, "actually has very profound cosmological data in it."
"The lumpiness bears an imprint of conditions very early on in the big bang because there's essentially nothing to change it later," he said. "So aside from probing the majority of atoms in the universe, you also end up getting fundamental cosmological information about what were the conditions the instant after the big bang."
Più nel dettaglio non so rispondere :D
missione completata domenica
entro quanto avremo foto nuove di hubble per saggiare le nuove potenzialita'?
entro quanto avremo foto nuove di hubble per saggiare le nuove potenzialita'?
La fase di commissionamento dura 4 mesi, le osservazioni scientificamente significative inizieranno dopo qualche settimana:
Q: Review commissioning period, when can observations with Hubble start?
A: Called SMOV (servicing mission observatory verification). About 4 months of intense activity to focus, checkout and calibrate instruments. Aiming for early September this year. Not much real science for the next several weeks. After that we will start worthwhile observations.
5 Spinoffs from the Hubble Space Telescope
As we wait (impatiently) for the Hubble Space Telescope to return to action following its repair and updating by the STS-125 astronauts, it is easy to think about how Hubble has impacted society. Hubble has become a household name, bringing astronomy to the masses with its dramatic images of the cosmos. It has also changed our understanding of the universe. But there's more ways that HST has impacted the world. Various technologies developed for the famous orbiting telescope have helped create or improve several different medical and and scientific tools. Here are five technology spinoffs from Hubble:
Micro-Endoscope for Medical Diagnosis:
The same technology that enhances HST’s images are now helping physicians perform micro-invasive arthroscopic surgery with more accurate diagnoses. Hubble technology helped improve the micro-endoscope, a surgical tool that enables surgeons to view what is happening inside the body on a screen, eliminating the need for a more invasive diagnostic procedure. This saves time, money and lessens the discomfort patients experience.
CCDs Enable Clearer, More Efficient Biopsies
Charge coupled devices (CCDs) used on the HST to convert light into electronic files—such as a distant star’s light directly into digital images—have been adapted to improve imaging and optics here on Earth. When scientists realized that existing CCD technology could not meet scientific requirements for the Hubble’s needs, NASA worked with an industry partner to develop a new, more advanced CCD. The industry partner then applied many of the NASA-driven enhancements to the manufacture of CCDs for digital mammography biopsy techniques, using CCDs to image breast tissue more clearly and efficiently. This allows doctors to analyze the tissue by stereotactic biopsy, which requires a needle rather than surgery.
Mirror Technology Increases Semiconductor Productivity, Performance
The semiconductor industry has benefitted from the ultra-precise mirror technology that gives the HST its full optical vision and telescopic power. This technological contribution helped improve optics manufacturing in microlithography—a method for printing tiny circuitry, such as in computer chips. The system uses molecular films that absorb and scatter incoming light, enabling superior precision and, consequently, higher productivity and better performance. This translates into better-made and potentially less costly computer circuitry and semiconductors.
Software Enhances Other Observatories
With the help of a software suite created by a NASA industry partner in 1995, students and astronomers were able to operate a telescope at the Mount Wilson Observatory Institute via the Internet. The software is still widely in use for various astronomy applications; using the CCD technology, the software locates, identifies, and acquires images of deep sky objects, allowing a user to control computer-driven telescopes and CCD cameras.
Optics Tool Sharpens Record-Breaking Ice Skates
Current Olympic record-holding speed skater Chris Witty raced her way to a gold medal in the 1,000-meter at the 2002 Salt Lake City Winter Olympics. Witty and other American short- and long-track speed skaters used a blade-sharpening tool designed with the help of NASA Goddard Space Flight Center and technology from HST. NASA had met with the U.S. Olympic Committee and helped to develop a new tool for sharpening speed skates, inspired by principles used to create optics for the HST. Speed skates sharpened with this new instrument demonstrated a marked improvement over conventionally sharpened skates.
Fonte (http://www.universetoday.com/2009/06/16/5-spinoffs-from-the-hubble-space-telescope/)
foto nuove dall hubble potenziato che mostrano a pieno le sue nuove qualita'?
foto nuove dall hubble potenziato che mostrano a pieno le sue nuove qualita'?
qualche giorno fa hanno interrotto le operazioni di test/calibrazione per effettuare un'osservazione straordinaria a Giove.
un australiano con il suo telescopio aveva infatti scoperto una nuova macchia nera su giove. Questa osservazione amatoriale si è poi rivelata fondata e molti telescopi sono stati puntati sul gigante gassoso per osservare questa macchia nera nell'emisfero sud (stimata grande quanto l'oceano indiano).
http://imgsrc.hubblesite.org/hu/db/images/hs-2009-23-a-print.jpg
Credit:NASA
da Hubblesite:
http://hubblesite.org/newscenter/archive/releases/2009/23/full/
l'articolo su SFN:
http://www.spaceflightnow.com/news/n0907/24jupiterhst/index2.html
l'articolo su Space Daily:
http://www.spacedaily.com/reports/Hubble_Space_Telescope_Captures_Rare_Jupiter_Collision_999.html
Countdown to Brand New Hubble Images
It's a countdown of cosmic proportions! In just six days, NASA will release the first images from the newly refurbished Hubble Space Telescope. These Early Release Observations (EROs) will be showcased at news briefings from NASA Headquarters at 15:00 GMT and 16:00 GMT (11 a.m. and noon EDT) Wednesday, Sept. 9 on NASA TV. The past few weeks, the Hubble team has concentrated on making high-priority science observations and finishing up instrument calibrations. Any clues as to what the first new images will include? Hubble scientists say the new images will be the first true display of the power of Hubble's new technology, dazzling amateur and professional astronomers with a wealth of new information and areas for research. Here's what the Hubble team has been working the past few weeks:
•The Wide Field Camera 3 (WFC3) has been completing its checkout, but it is now taking science images on a regular basis.
•The Space Telescope Imaging Spectrograph (STIS) is finished with its calibration activities and completing its work in support of Hubble’s EROs.
•The Cosmic Origins Spectrograph (COS) is in the final phases of its calibrations for both its near-ultraviolet and far-ultraviolet channels. The channels, which study different wavelengths of ultraviolet light, must be calibrated separately. For example, engineers and scientists are continuing to test the focus for the far-ultraviolet channel, while the near-ultraviolet channel’s focus appears to be good.
•The cooling system for the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) has cooled the instrument down to operational levels, which is great news. NICMOS was not serviced during the STS-125 mission, but it was shut down in September 2008 following an anomaly during a spacecraft computer update. Engineers tried turning it on in July 2009, but the cooling system failed. But on on August 1, the cooling system restarted without the previous problems. "NICMOS began cooling efficiently," said Frank Summers in the Hubble Blog, "and actually faster than expected. Note that when we say “cool,” we really mean “cold.” Really cold. Beyond Arctic, mind-numbing, freezingly cold. NICMOS is cooled to -321 degrees Fahrenheit. That’s the temperature needed for infrared observations."
It takes NICMOS more than a week to achieve that temperature. Then the instrument must show stability at those temperatures for science to be possible. Engineers have now turned on the detectors to begin the several-week calibration process for NICMOS. So far so good, and surely we'll hear more about NICMOS during the news briefing next week.
link (http://www.universetoday.com/2009/09/03/countdown-to-brand-new-hubble-images/)
Hubble è tornato in attività :)
Hubble Wows With New Images (http://www.universetoday.com/2009/09/09/hubble-wows-with-new-images/)
http://www.universetoday.com/wp-content/uploads/2009/09/Butterfly-emerges-from-New-Hubble-images.-580x435.jpg
Hubble is back! The wait is over and here are the new pictures from the newly refurbished Hubble Space Telescope. Above is an image taken by the Wide Field Camera 3 (WFC3), a new camera aboard NASA’s Hubble Space Telescope, installed by NASA astronauts in May 2009, during the servicing mission to upgrade and repair the 19-year-old Hubble telescope. This is a planetary nebula, catalogued as NGC 6302, but more popularly called the Bug Nebula or the Butterfly Nebula.
NGC 6302 lies within our Milky Way galaxy, roughly 3,800 light-years away in the constellation Scorpius. The glowing gas is the star’s outer layers, expelled over about 2,200 years. The "butterfly" stretches for more than two light-years, which is about half the distance from the Sun to the nearest star, Alpha Centauri.
And there's more!
http://www.universetoday.com/wp-content/uploads/2009/09/Hubble-starfield.jpg
This one is absolutely awesome! This zoom into the globular star cluster Omega Centauri converges onto the Hubble Wide Field Camera 3’s panoramic view of 100,000 stars lying in the center of the cluster. The stars vary in age and change color as they get older. Most of them are middle-aged, yellowish stars like our Sun. But as they near the end of their lives, they balloon into red giants, and later still, into hot, blue stars.
http://www.universetoday.com/wp-content/uploads/2009/09/Stephans-Quintet-580x435.jpg
This portrait of Stephan’s Quintet, also known as Hickson Compact Group 92, was taken by the new Wide Field Camera 3 (WFC3) aboard NASA’s Hubble Space Telescope. Stephan’s Quintet, as the name implies, is a group of five galaxies. The name, however, is a bit of a misnomer. Studies have shown that group member NGC 7320, at upper left, is actually a foreground galaxy about seven times closer to Earth than the rest of the group.
Three of the galaxies have distorted shapes, elongated spiral arms, and long, gaseous tidal tails containing myriad star clusters, proof of their close encounters. These interactions have sparked a frenzy of star birth in the central pair of galaxies. This drama is being played out against a rich backdrop of faraway galaxies.
The image, taken in visible and infrared light, showcases WFC3’s broad wavelength range.
Observations by the newly repaired Space Telescope Imaging Spectrograph (STIS) on Hubble reveals the signature balloon-shaped clouds of gas blown from a pair of massive stars called Eta Carinae. This new observation shows some of the chemical elements that were ejected in the eruption seen in the middle of the 19th century.
STIS analyzed the chemical information along a narrow section of one of the giant lobes of gas. In the resulting spectrum, iron and nitrogen define the outer boundary of the massive wind, a stream of charged particles, from Eta Car A, the primary star. The amount of mass being carried away by the wind is the equivalent one sun every thousand years. While this "mass loss" may not sound very large, in fact it is an enormous rate among stars of all types. A very faint structure, seen in argon, is evidence of an interaction between winds from Eta Car A and those of Eta Car B, the hotter, less massive, secondary star.
Eta Car A is one of the most massive and most visible stars in the sky. Because of the star’s extremely high mass, it is unstable and uses its fuel very quickly, compared to other stars. Such massive stars also have a short lifetime, and we expect that Eta Carinae will explode within a million years.
http://www.universetoday.com/wp-content/uploads/2009/09/Hubble-ERO-Barred-Spiral.jpg
This image of barred spiral galaxy NGC 6217 is the first image of a celestial object taken with the newly repaired Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope. The camera was restored to operation during the STS-125 servicing mission in May to upgrade Hubble. The barred spiral galaxy NGC 6217 was photographed on June 13 and July 8, 2009, as part of the initial testing and calibration of Hubble's ACS. The galaxy lies 6 million light-years away in the north circumpolar constellation Ursa Major. The blue haze at the edges are baby stars being born.
About Hubble's repair, NASA's Ed Weiler said, "The astronauts basically did a total repair job on Hubble, and fixed two instruments that haven't been working for a long time. It's not an 19 year old telescope, it’s a new telescope again."
NASA admisinatrator Charlie Bolden, who participated in an earlier Hubble repair mission, said at the press conference unveiling the new images that "after almost twenty years of service we are so proud and honored to part of the Hubble story. The telescope is now equipped to last well into the next decade. Hubble is one of the most accomplished scientific instruments ever, and it has captured the imagination of people everywhere."
For the full gallery of new Hubble images, see this NASA webpage.
And here's one more: a full view of Jupiter with the impact scar visible.
Nuovi strumenti vs vecchi strumenti
Just How Good is the "New" Hubble? Let's Compare (http://www.universetoday.com/2009/09/09/just-how-good-is-the-new-hubble-lets-compare/)
http://www.universetoday.com/wp-content/uploads/2009/09/Writing-Images3.jpg
Hubble images of the Omega Centauri starfield from 2002, left, and from 2009, right.
"This marks a new beginning for Hubble," said Ed Weiler, associate administrator for NASA's Science Mission Directorate at today's press briefing at NASA Headquarters to showcase the images from Hubble following Servicing Mission 4. "The telescope was given an extreme makeover and is now significantly more powerful than ever — well equipped to last well into the next decade."
But how much more powerful is Hubble? Are there any discernible differences between the old images from Hubble and the new ones released today? You better believe it. Above is the star field of Omega Centauri before (2002) and after (2009).
See more comparisons below.
http://www.universetoday.com/wp-content/uploads/2009/09/b4-after-580x435.jpg
Butterfly Nebula before and after. Credit: NASA/Hubble team. Collage by Stuart Atkinson
Here's an earlier image of the Butterfly Nebula (NGC 6302, or the Bug Nebula) with the one released today. (Thanks to Stu Atkinson for the comparison image.)
Scientists at today's briefing said the new instruments are more sensitive to light and therefore will significantly improve Hubble’s observing efficiency. The space telescope is now able to complete observations in a fraction of the time that was needed with earlier generations of Hubble instruments.
http://www.universetoday.com/wp-content/uploads/2009/09/Writing-Images4-1.jpg
Stephan's Quintet from 2000 (left) and 2009 (right) Credit: NASA/ESA Hubble Team
And here's Stephan's Quintet from 2000 (left) and 2009 (right).
Need we say more?
+Benito+
09-09-2009, 20:05
parte della differenza è però evidentemente dovuta a differenti calibrazioni e/o a differenti lunghezze d'onda di osservazione, diversamente non potrebbero cambiare i colori (spesso falsi).
Tra l'altro la nebulosa farfalla spero sia stata osservata in due lunghezze d'onda diverse o non si spiega un così radicale cambiamento di aspetto in soli 7 anni.
parte della differenza è però evidentemente dovuta a differenti calibrazioni e/o a differenti lunghezze d'onda di osservazione, diversamente non potrebbero cambiare i colori (spesso falsi).
Tra l'altro la nebulosa farfalla spero sia stata osservata in due lunghezze d'onda diverse o non si spiega un così radicale cambiamento di aspetto in soli 7 anni.
Forse è dovuto ad una maggiore sensibilità dello strumento a determinate lunghezze d'onda..
parte della differenza è però evidentemente dovuta a differenti calibrazioni e/o a differenti lunghezze d'onda di osservazione, diversamente non potrebbero cambiare i colori (spesso falsi).
Tra l'altro la nebulosa farfalla spero sia stata osservata in due lunghezze d'onda diverse o non si spiega un così radicale cambiamento di aspetto in soli 7 anni.
Penso che volessero mettere in evidenza il fatto che i nuovi strumenti oltre alla maggiore sensibilità coprono anche più lunghezze d'onda dei vecchi permettendo quindi di osservare "dettagli" prima non osservabili.
Edit: Oppure è come dice Octane (o una via di mezzo). Non ho le conoscenze per dirlo :D
+Benito+
09-09-2009, 21:54
Mi sono accorto solo ora che la foto della nebulosa farfalla è un po' "artefatta", nel senso che hanno confrontato due foto non della stessa cosa, visto che quella "vecchia" è la parte "alta" ribaltata e non la parte "bassa".
incomprensibile, francamente.
Mi sono accorto solo ora che la foto della nebulosa farfalla è un po' "artefatta", nel senso che hanno confrontato due foto non della stessa cosa, visto che quella "vecchia" è la parte "alta" ribaltata e non la parte "bassa".
incomprensibile, francamente.
Come scriveva Rand, sul sito della Nasa una delle foto fa chiaramente vedere che i nuovi strumenti beneficiano di uno spettro più ampio, fornendo quindi dati per i quali è impossibile un confronto diretto, per il resto mi vien da pensare che queste foto comparative siano state fatte a beneficio del grande pubblico e non di coloro che da queste immagini vogliono ricavarne un valore scientifico.
Da qualche parte sono scaricabili le immagini "calibrate" in formato nativo (o ancor meglio per i comuni mortali in TIFF)?
per il resto mi vien da pensare che queste foto comparative siano state fatte a beneficio del grande pubblico e non di coloro che da queste immagini vogliono ricavarne un valore scientifico.
*
In particolare il confronto della nebulosa dovrebbe essere stato fatto da un utente di unmannedspaceflight.com ed è effettivamente "girato" (ha poi postato la versione corretta)
Da qualche parte sono scaricabili le immagini "calibrate" in formato nativo (o ancor meglio per i comuni mortali in TIFF)?
Se parli delle prime dopo il rinnovamento di Hubble puoi trovarle qui (http://www.hubblesite.org/newscenter/archive/releases/2009/25/image/) (sotto "Highest-quality download options" nelle singole foto).
Salve,
la missione di servizio è andata tutta ok?
mi pare di aver capito che ACS è ancora zoppo.. e non funziona del tutto...
mentre gli altri vecchi strumenti stis e nicmos?
Salve,
la missione di servizio è andata tutta ok?
mi pare di aver capito che ACS è ancora zoppo.. e non funziona del tutto...
mentre gli altri vecchi strumenti stis e nicmos?
A quanto ne so funziona tutto meno uno dei 3 canali di ACS (di cui comunque non era prevista la riparazione).
ciao,
conseguenze scientifiche della mancanza 3°canale?
ciao,
conseguenze scientifiche della mancanza 3°canale?
Non ne ho idea :D
(Negli articoli che ho letto non è specificato e non ho minimamente le conoscenze per dirlo "da solo")
Qualche dato più preciso su "vecchi strumenti vs nuovi":
How does Hubble compare? (http://www.planetary.org/blog/article/00002099/)
Apologies in advance for the number of acronyms in this post. There's no way to get around them.
Last week when the new, post-servicing-mission-4 capabilities of Hubble were unveiled, I kept asking myself: How do Hubble's new capabilities compare to what it could do before the servicing mission, and how do they compare to what we can do from the ground? I fired off some questions to Heidi Hammel, and did some research on my own within the Hubble instrument description documents.
There's four main Hubble instruments I was interested in comparing with each other and to Earth:
* The Wide Field and Planetary Camera 2 (WFPC2), an ultraviolet- to very near-infrared imager, Hubble's workhorse from 1993 to 2009;
* the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS), a near-infrared imager, installed in 1997, which has had periodic problems with its cooling system and was most recently offline from November 2008 to August 2009;
* the Advanced Camera for Surveys (ACS), an ultraviolet- to very near-infrared imager, in use since 2002 but with a hiccup in 2007, mostly repaired in May 2009; and
* the newly-installed Wide Field Camera 3 (WFC3), which replaced WFPC2 in May 2009 and was also intended to largely supplant NICMOS.
Here's the executive summary: what WFC3 brings to the party is a killer combination of large field of view and pretty high resolution. It's an improvement on WFPC2 in almost every way. It improves marginally on the resolution of the largest-field-of-view optical images that Hubble was capable of before (ACS Wide Field camera), and it really beats the pants off of the field of view of NICMOS, though at lower resolution than NICMOS can manage. (So it's a good thing that they're now reporting progress on getting NICMOS' cooling system working again.) And although Earth-based instruments at the Keck, VLT, and Gemini observatories can beat Hubble resolution using adaptive optics, that's only at near-infrared wavelengths; shorter than 800 nanometers (and especially in the ultraviolet) there's nothing on Earth that can get sharper images than Hubble.
I spent a couple of hours this morning noodling around the Space Telescope Science Institute website reading instrument descriptions. I came up with the following diagram that compares the capabilities of the different instruments. The top row (above the dashed line) compares fields of view -- how much of the sky each one takes in. (For comparison, the Moon at 30 arcminutes or 1800 arcseconds across would be about twice the width of the whole diagram.) The bottom row (below the dashed line) compares pixel sizes. Ideally you'd like to maximize field of view and minimize pixel size.
http://www.planetary.org/image/hubble_fov_pixelscale_lg.png
Top row: the fields of view for five Hubble instruments are compared. Bottom row: single pixel sizes for four of the instruments. STIS: Space Telescope Imaging Spectrograph. NICMOS: Near-Infrared Camera and Multi-Object Spectrometer, which has three independent cameras NIC1, NIC2, and NIC3. ACS: Advanced Camera for Surveys, which has three channels: Wide Field, Solar Blind, and High Resolution. WFPC2: Wide Field and Planetary Camera 2, which has two channels: Wide Field and Planetary Camera. WFC3: Wide Field Camera 3, which has two channels: Ultraviolet-Visible and Infrared. Credit: Emily Lakdawalla, based on Space Telescope Science Institute documentation
I took these diagrams directly from the instrument descriptions. The skewed appearance of the ACS fields of view is real -- it has something to do with the optics within Hubble. Also real is how some of the detectors on some instruments have overlapping fields of view (like those in WFPC2 and WFC3), while others (like those in NICMOS) are spread out on the sky, intended to be used totally independently.
Here's a table summarizing the same geometric information, plus info on detector size and wavelength sensitivity.
...
Now, what I really wanted to be able to do was to post a similar diagram, extending the comparison to Earth-based observatories. But after spending part of the morning trying to understand all the different variables and how they relate to each other, I didn't think I could. Here's what I can tell you. I asked Heidi Hammel to tell me which Earth-based instruments were most appropriate for comparison to Hubble. She gave me the names of three instruments that work on major scopes equipped with Adaptive Optics (AO). AO corrects Earth-based telescope images in real-time, as light is falling on the detectors, for the distortions caused by Earth's moving, shimmering atmosphere. They are:
* NIRC2 on the Keck II telescope on Mauna Kea, Hawaii;
* NaCo on the Very Large Telescope (VLT) at Cerro Paranal, Chile; and
* the NIRI imager with ALTAIR adaptive optics system at Gemini North Observatory, also on Mauna Kea.
After a couple of hours of reading I must admit to hopeless confusion. What I can tell you is that all three Earth-based instruments are similar in that they have 1024-by-1024-pixel detectors behind three different cameras with three different fields of view. Keck II has the narrowest fields of view (10, 20, and 40 arcseconds) and correspondingly highest angular resolution of the three; NaCo is pretty similar to Keck II (14, 28, and 56 arcseconds); and Gemini North has the widest fields of view (22, 51, and 120 arcseconds) and correspondingly lowest resolution. The problem is that the size of pixels on Earth-based telescopes is not nearly as good a measure of what they can resolve as they are for a space-based imager; even with adaptive optics, there's always some blur. On top of that, the performance of Adaptive Optics systems is at its best at the point in an image where there is a guide star (natural or artificial) to give the computers a clue how to correct for the blurring effect of the atmosphere, and degrades away from that. Finally, Adaptive Optics only works at infrared wavelengths (why? I'll answer that question in a future Planetary Radio Q and A). So I decided it just didn't make sense to do a direct comparison.
Why not just pick a few interesting objects out there in space and actually look at some comparable images? Nancy Atkinson over at Universe Today already did that for some Hubble targets, though she didn't specify which cameras the before and after images came from. I searched for some things to compare between the newly released Hubble images and the Earth-based ones that Heidi suggested I check, but I couldn't find anything comparable. I believe that the reason for that is the newest Hubble releases were selected in order to showcase the broad field of view of the new Wide Field Camera 3, and none of those Earth-based imagers holds a candle to WFC3 (or ACS's Wide Field channel, for that matter) in field of view.
In the end I feel like this was not a very productive use of my day! I guess what I've learned is that there isn't an easy answer to the question of how all these facilities compare. Which one you'd like to use depends upon a complicated game, trading between resolution, fields of view, wavelength sensitivity, the kinds of filters available (something I didn't even get into here), and how hard it is to get a proposal approved for time on the instrument of your choice.
With that, I'd better quit, and move on to something else! Hopefully tomorrow I'll have more to show from a day's work.
Two Hubble STUNNERS! (http://blogs.discovermagazine.com/badastronomy/2009/09/30/two-hubble-stunners/)
If you thought the Lagoon yesterday was pretty, then reset your awe-meter. Check. This. Out.
http://blogs.discovermagazine.com/badastronomy/files/2009/09/hst_ngc4402.jpg (http://www.spacetelescope.org/images/html/heic0911c.html)
D’ya like that? Huh? Do ya? Had enough? No? Then check THIS out!
http://blogs.discovermagazine.com/badastronomy/files/2009/09/hst_ngc4522.jpg (http://www.spacetelescope.org/images/html/heic0911b.html)
Jeebus. Click either to brobdingnangate. In fact, you can get massively huge versions here and here. We’re talking 30 and 40 Mb each, so be ye fairly warned, says I.
Those magnificent images are of the galaxies NGC 4402 and NGC 4522, respectively, as seen by the Hubble Space Telescope’s Advanced Camera for Surveys (from before the recent repair mission). They’re both spiral galaxies in the Virgo Cluster, the nearest large collection of galaxies to us, roughly 60 million light years from Earth.
If they look funny to you, then good! The Virgo Cluster is massive, and has a lot of gravity. The galaxies bound to it are moving like bees surrounding a hive, each in its own orbit going every which way. These galaxies are screaming through the cluster at speeds of 10 million kilometers per hour, a truly terrifying velocity.
There is an ethereal gas distributed between the galaxies called the intercluster medium. It’s incredibly thin, but over the size of a galaxy — especially when said galaxy is barreling through it at such tremendous speed — the gas can exert significant pressure, called ram pressure. The pressure is actually blowing the galaxies’ internal gas clouds out into the cluster itself, making them look a little bit like pickup trucks driving down a highway with dirt copiously pouring out the beds*. This is especially obvious in NGC 4522 (the lower one), where you can see bright blue splotches, which are regions of intense star formation, along with dark lanes of dust actually above the galactic plane.
In NGC 4022, you can see how the ram pressure is roiling up the dust in the galaxy, and also blowing it back, though apparently not as briskly as in the other galaxy.
These pictures are incredible. Poke around them; you can see amazing detail in the galaxies themselves, as well as hundreds, maybe thousands of background galaxies.
It’s been a while since we’ve seen deep, glorious pictures of spiral galaxies from Hubble. Now that ACS is working again, and it’s being joined by the equally powerful Wide Field Camera 3, we’ll be seeing lots more of these. Get used to it.
4chr
Grazie alla Wide Field Camera 3 Hubble ha acquisito (http://hubblesite.org/newscenter/archive/releases/2009/31/) una nuova versione del Hubble Ultra Deep Field
http://img10.imageshack.us/img10/7668/hudfwf3.jpg (http://imgsrc.hubblesite.org/hu/db/images/hs-2009-31-a-full_jpg.jpg)
Hubble ha scoperto il più piccolo oggetto della fascia di Kuiper individuato finora:
Hubble Finds Smallest Kuiper Belt Object Ever Seen (http://www.onorbit.com/node/1819)
NASA's Hubble Space Telescope has discovered the smallest object ever seen in visible light in the Kuiper Belt, a vast ring of icy debris that is encircling the outer rim of the solar system just beyond Neptune. The needle-in-a-haystack object found by Hubble is only 3,200 feet across and a whopping 4.2 billion miles away. The smallest Kuiper Belt Object (KBO) seen previously in reflected light is roughly 30 miles across, or 50 times larger.
This is the first observational evidence for a population of comet-sized bodies in the Kuiper Belt that are being ground down through collisions. The Kuiper Belt is therefore collisionally evolving, meaning that the region's icy content has been modified over the past 4.5 billion years.
The object detected by Hubble is so faint -- at 35th magnitude -- it is 100 times dimmer than what the Hubble telescope can see directly.
So then how did the space telescope uncover such a small body?
In a paper published in the December 17th issue of the journal Nature, Hilke Schlichting of the California Institute of Technology in Pasadena, Calif., and her collaborators are reporting that the telltale signature of the small vagabond was extracted from Hubble's pointing data, not by direct imaging.
Hubble has three optical instruments called Fine Guidance Sensors (FGS). The FGSs provide high-precision navigational information to the space observatory's attitude control systems by looking at select guide stars for pointing. The sensors exploit the wavelike nature of light to make precise measurement of the location of stars.
Schlichting and her co-investigators determined that the FGS instruments are so good that they can see the effects of a small object passing in front of a star. This would cause a brief occultation and diffraction signature in the FGS data as the light from the background guide star was bent around the intervening foreground KBO.
They selected 4.5 years of FGS observations for analysis. Hubble spent a total of 12,000 hours during this period looking along a strip of sky within 20 degrees of the solar system's ecliptic plane, where the majority of KBOs should dwell. The team analyzed the FGS observations of 50,000 guide stars in total.
Scouring the huge database, Schlichting and her team found a single 0.3-second-long occultation event. This was only possible because the FGS instruments sample changes in starlight 40 times a second. The duration of the occultation was short largely because of the Earth's orbital motion around the Sun.
They assumed the KBO was in a circular orbit and inclined 14 degrees to the ecliptic. The KBO's distance was estimated from the duration of the occultation, and the amount of dimming was used to calculate the size of the object. "I was very thrilled to find this in the data," says Schlichting.
Hubble observations of nearby stars show that a number of them have Kuiper Belt-like disks of icy debris encircling them. These disks are the remnants of planetary formation. The prediction is that over billions of years the debris should collide, grinding the KBO-type objects down to ever smaller pieces that were not part of the original Kuiper Belt population.
The finding is a powerful illustration of the capability of archived Hubble data to produce important new discoveries. In an effort to uncover additional small KBOs, the team plans to analyze the remaining FGS data for nearly the full duration of Hubble operations since its launch in 1990.
For illustrations, and more information, visit:
* http://hubblesite.org/news/2009/33
* http://www.nasa.gov/hubble
Meno di 1 Km di "diametro"! :eek:
Notevole anche il modo (utilizzando i Fine Guidance Sensors):
http://imgsrc.hubblesite.org/hu/db/images/hs-2009-33-c-web.jpg (http://hubblesite.org/newscenter/archive/releases/2009/33/image/c/format/web_print/)
(click per versione grande)
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