View Full Version : [Space] NASA's GENESIS Misison's sample return webcast
NASA's Genesis Mission (http://genesismission.jpl.nasa.gov/)
NASA's Genesis Webcast (http://www.jpl.nasa.gov/webcast/genesis/)
Live Webcast ( rtsp://rmbcast.nasa-us2e.speedera.net/alias_ashburn1_btn_2/broadcast/rmbcast.nasa-us2e/rmbcast_nasa-us2e_dec312003_0922_52880.rm)
WEDNESDAY, SEPTEMBER 8, 2004
1500 GMT (11:00 a.m. EDT)
The sample return capsule is barrelling toward Earth's atmosphere having successfully separated from the main body of the Genesis spacecraft earlier this morning. The capsule, which contains the precious collection of solar wind samples, has no propulsion system -- it is simply aimed to the precise trajectory "keyhole" for entry into the atmosphere with no way to abort the homecoming now.
Mission navigators expect the capsule to hit the top of Earth's atmosphere at an altitude of 400,000 feet around 1555 GMT (11:55 a.m. EDT). The target "keyhole" is roughly 20.5 miles long and 6.2 miles wide over the Pacific Ocean. If the capsule enters the atmosphere anywhere inside this corridor, it will come down over the designated spot on the Utah Test & Training Range, NASA says.
After its fiery plunge through the atmosphere, a series of chutes and a large parafoil will slow the capsule in preparation for a mid-air recovery by a helicopter.
Stanno partendo i due elicotteri.
1518 GMT (11:18 a.m. EDT)
The pilots are making final preparations for takeoff. There are two helicopters ready to retrieve the Genesis capsule -- one primary and one backup. They will have time to make about 5 tries to grab the descending capsules.
1520 GMT (11:20 a.m. EDT)
The choppers have started up. Each specially outfitted helicopter has a three-person crew.
1525 GMT (11:25 a.m. EDT)
Both the primary red-colored "Vertigo" helicopter and the backup blue-painted "South Coast" choppers have just taken off from their staging point in Utah. They will fly into position for the upcoming retrieval of Genesis. It is a beautiful, clear morning at the recovery zone.
1530 GMT (11:30 a.m. EDT)
The capsule is currently high above the Pacific Ocean between Hawaii and the U.S. West Coast. It is scheduled to hit the atmosphere for reentry in about 25 minutes.
1533 GMT (11:33 a.m. EDT)
A military Blackhawk helicopter is escorting the primary and backup capture helicopters. The three choppers are flying toward a spot 7.5 miles away from the recovery position at an altitude of 10,000 feet where they will wait for Genesis.
1535 GMT (11:35 a.m. EDT)
"The lead helicopter will deploy an 18-1/2-foot pole with what you could best describe as an oversized, space-age fishing hook on its end," said Roy Haggard, chief executive officer of Elsinore, Calif.-based Vertigo Inc. and director of helicopter flight operations. "When we make the approach we want the helicopter skids to be about eight feet above the top of the parafoil. If for some reason the capture is not successful, the second helicopter is 1,000 feet behind the first one and setting up for its approach. We estimate we will have five opportunities to achieve capture."
1537 GMT (11:37 a.m. EDT)
The helicopters are now 6,200 feet in altitude.
1542 GMT (11:42 a.m. EDT)
The primary capsule recovery chopper, called Vertigo, reports it is three minutes from reaching its standby position in the sky over Utah.
1545 GMT (11:45 a.m. EDT)
Now 10 minutes from the time Genesis will begin atmospheric entry over northern Oregon. The capsule plunge to the atmosphere at a velocity of approximately 24,700 miles per hour. The only human-made object to re-enter Earth's atmosphere at a higher speed was the Apollo 10 command module, which reached 24,861 mph.
Genesis will be stabilize with its nose down because of the location of its center of gravity, its spin rate and its aerodynamic shape.
1550 GMT (11:50 a.m. EDT)
Tracking systems are operating to acquire the capsule as it falls back to Earth.
As the capsule descends through the atmosphere, it will be "painted" by powerful radars located on the Utah Test & Training Range. This will provide tracking information allowing ground-based cameras to spot the capsule.
Backup tracking is provided by a Global Positioning System unit on the Genesis capsule that transmits position data to a ground station, which in turn relays the information to the mission control center.
The radar, visual and GPS data will provide an accurate plot in three dimensions for the capsule's location. This plot is generated at the mission control center located about 100 miles away from the range at Hill Air Force Base. A ground control intercept officer based at the Hill Air Force Base mission control will direct helicopter flight crews towards the capsule.
1554 GMT (11:54 a.m. EDT)
The capsule has been spotted high over the planet!
The Genesis sample return capsule has hit the upper fringes of Earth's atmosphere 400,000 feet above the planet for its trek home. The capsule contains samples of the solar wind that were collected a million miles from Earth during the three-year Genesis mission.
About 45 seconds after entry interface, the capsule will be exposed to a deceleration force three times the force of Earth gravity, or 3 G's. This arms a timer that is started when the deceleration force passes back down through 3 G's. All of the parachute releases are initiated from this timer.
1555 GMT (11:55 a.m. EDT)
After one minute of atmospheric descent, the capsule should be at an altitude of 197,000 feet as the heat shield temperature reaches a peak temperature of 4,500 degrees F.
Slightly over 10 seconds later, the capsule will be exposed to about 30 G's, the greatest deceleration it will endure during Earth entry. During this time period, the capsule's heat shield will lose an estimated about 7 pounds, or about 6 percent of its weight, as a small amount of the ablative material erodes away with the heat generated during entry through the atmosphere.
1556 GMT (11:56 a.m. EDT)
Just over two minutes since entry interface. The capsule should be at an altitude of 108,000 feet as a mortar aboard the capsule will fire, releasing the 6.7-foot drogue parachute to provide stability to the capsule until the main chute is released. The capsule's heat shield will rapidly cool during this subsonic portion of the descent.
1557 GMT (11:57 a.m. EDT)
The capsule appears to be tumbling!
1558 GMT (11:58 a.m. EDT)
The Genesis sample return capule is rapidly tumbling with no chute.
1558 GMT (11:58 a.m. EDT)
IMPACT! The capsule has slammed into the Utah desert after failing to deploy its chutes and parafoil.
1559 GMT (11:59 a.m. EDT)
The capsule is half buried into the ground. But it appears to be mainly intact.
1601 GMT (12:01 p.m. EDT)
The impact point is 40.07 degrees by 113.30 degrees in Utah.
1602 GMT (12:02 p.m. EDT)
NASA's Genesis sample return capsule has suffered a major anomaly during homecoming today, failing to release its chutes and parafoil to slow the descent for a mid-air recovery. The craft plunged into ground a high rate of speed. The status of the solar wind samples is not yet known.
1604 GMT (12:04 p.m. EDT)
Mission control says without the drogue chute and subsequent parafoil, the capsule would hit the ground at about 100 mph.
1605 GMT (12:05 p.m. EDT)
There is no indication what might have caused Genesis' problem. NASA says there will be an investigation to determine why the speed-slowing chute and parafoil failed to deploy.
1609 GMT (12:09 p.m. EDT
An overhead view of the impact point shows the capsule half-buried on its side. The craft appears to be badly damaged.
1610 GMT (12:10 p.m. EDT)
Recovery forces are moving toward the capsule, which has made a very spectacular crater.
1614 GMT (12:14 p.m. EDT)
NASA officials hope there is enough of the capsule intact to determine what caused the chute deployment failure. Whether the solar wind samples will yield any science value remains to be seen. Scientists had said the samples had to be keep in ultra-clean conditions to preserve the information. However, the capsule is significantly broken as it sits on the desert floor after a high-speed impact.
1615 GMT (12:15 p.m. EDT)
The recovery helicopters that were supposed to snag the returning Genesis capsule have now landed next to the capsule.
1615 GMT (12:15 p.m. EDT)
The chopper crews have bene told to be cautious. The motar that should have fired on the capsule to deploy the chute may still be armed.
1617 GMT (12:17 p.m. EDT)
Personnel are walking toward the capsule, but keeping their distance due to concerns about the motar being live.
1618 GMT (12:18 p.m. EDT)
Mission control says the mortar may still be armed, having failed to fire during descent. Another scenario is the mortar fired and the drogue chute deployed only to break off as the craft plunged back to Earth.
1620 GMT (12:20 p.m. EDT)
Here is what should have happened:
Just over two minutes since entry interface the capsule would be at an altitude of 108,000 feet as a mortar aboard the capsule fired, releasing the 6.7-foot drogue parachute to provide stability to the capsule until the main chute is released. The capsule's heat shield will rapidly cool during this subsonic portion of the descent.
About four minutes later, three pyrotechnic bolts were to release the drogue chute from the capsule at an altitude of about 22,000 feet. As the drogue chute moved away, it would extract the capsule's main chute, a 34.6- by 12.1-foot parafoil. Full inflation of the parafoil would occur in about 6 seconds. Once inflation is complete, the parafoil and its payload will begin a slow, loose spiral descent through the skies of the Utah Test & Training Range.
However, the capsule was in a tumble and none of the chutes deployed to slow the capsule. That thwarted any mid-air recovery.
1622 GMT (12:22 p.m. EDT)
The recovery forces at the impact site report the chute never deployed. Therefore, they are treating the capsule as a "hot" craft since the mortar could be still armed.
1624 GMT (12:24 p.m. EDT)
Tracking teams are preserving all of their data for the failure investigation.
1625 GMT (12:25 p.m. EDT)
There is nine people at the impact site now to survey the situation. One is taking up-closing imagery.
1627 GMT (12:27 p.m. EDT)
Additional personnel are en route. They will safe the capsule for its removal from the impact crater.
1630 GMT (12:30 p.m. EDT)
Mission control reports the navigation and targeting of the capsule for reentry was on the mark. However, a failure aboard the capsule prevented the chute and parafoil to deploy. That resulted in the capsule's impact.
NASA plans to hold a news conference later this afternoon.
Genesis capsule crashes in Utah
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: September 8, 2004
A small spacecraft carrying priceless samples of the sun crashed into the Utah desert today when its stabilizing parachute failed to deploy, bringing an innovative $264 million mission, NASA's first sample return flight since the Apollo moonshots, to a disappointing end.
The Genesis sample return canister was to have been plucked out of mid air by a helicopter flown by a Hollywood stunt pilot over the Utah Test and Training Range. But a drogue chute needed to stabilize the craft before deployment of its large parafoil never fired and the craft slammed into the ground at about 100 mph.
Video showed the canister half buried in the Utah desert, largely intact. But the mid-air recovery had been planned because the system used to capture particles from the sun was exceptionally fragile and it was believed a ground landing, even under a parachute, would have caused extensive breakage.
Engineers may be able to salvage some of the planned science from whatever is left, but at this point it's not yet clear whether that will be possible.
"Whether or not we can recover any of the science from this remains to be seen," said Chris Jones, a senior manager at the Jet Propulsion Laboratory in Pasadena, Calif. "Clearly, we're going to do all we can to recover science from the capsule. But the capsule obviously wasn't designed to withstand this kind of impact."
Hitting the atmosphere at 24,700 mph, the 450-pound sample canister's energy of motion was equivalent to that of a 4.5-million-pound freight train moving at 80 mph. In seconds, most of that energy was converted into heat, subjecting the probe's heat shield to temperatures up to 4,700 degrees and slowing the craft with a braking force of 30 times Earth's gravity.
Two minutes after entry began, at an altitude of about 21 miles, the small drogue parachute was to have unfurled to stabilize the craft and four minutes after that, at an altitude of about 22,000 feet, a wing-like parafoil was to deploy, slowing the craft's descent to a gentle 10 to 12 miles per hour.
Down below, two helicopters piloted by Hollywood stunt pilots were waiting, flying a criss-cross pattern along the spacecraft's ground track across the Utah Test and Training Range, an isolated military reservation where munitions and unpiloted aircraft are tested.
Using radio beacons and radar tracking, one of the helicopters, piloted by Cliff Fleming of South Coast Helicopters in Santa Ana, Calif., was to have moved in for a mid-air recovery, snaring the parafoil with a large hook on the end of a pole mounted to one of the chopper's landing skids.
After attaching a nitrogen purge to protect the solar particles from earthly contamination, the sample canister was to have been trucked to the Johnson Space Center in Houston and moved into an ultra-clean laboratory for detailed scientific analysis.
But it was not to be. Instead, engineers will pour over what data they have to figure out what might have gone wrong.
Why did NASA spend more than $264 million to capture a few wisps of the solar wind? Because those traces are expected to serve as a sort of cosmic Rosetta stone, providing critical insights into the birth and evolution of our solar system.
The streaming solar wind originates in the sun's outer atmosphere. It is made up of electrons, protons and trace amounts of various atomic nuclei that are unchanged since the birth of the solar system.
In that sense, the solar wind is nothing less than a sample of the original cloud of gas and dust that coalesced to form the sun and its retinue of planet some 4.6 billion years ago. Capturing a sample of this raw material is the goal of NASA's innovative Genesis mission.
"The composition of the solar wind is a clue to the composition of the outer layers of the surface of the sun, which in turn is the composition of the solar nebula from which all the planets formed," Donald Burnett, principal investigator of the Genesis mission, said before launch in 2001. "That's the connection."
Scientists believe the sun and other stars in this neighborhood of the Milky Way galaxy formed inside a vast molecular cloud that has since thinned out and dissipated. The stars formed when areas of slightly higher density contracted under their own gravity to form flattened, rotating solar nebulae.
As gravitational contraction continued in a given cloud, densities in the inner region eventually reached levels high enough to trigger nuclear fusion and a star was born. Material circling the infant sun clumped together to form planets, moons, asteroids and comets.
So far so good. But the details of this complex process - how the solar system evolved from a fairly homogenous cloud of dusty debris to the myriad objects we see today - are poorly understood. By determining the initial composition of the solar nebula, scientists had hoped to fill in the blanks.
"Most of our models and how we understand the formation and evolution of the solar system, processes that formed our planets, asteroids, comets and ... planetary atmospheres, all of that requires an assumption of an initial starting composition of our solar system," Meenakshi Wadhwa, a cosmochemist with the Field Museum in Chicago, said before launch.
Knowing the actual starting composition would "have a tremendous impacting of these on our understand areas."
"The sun has basically more than 99 percent of the mass of the solar system in it," Wadhwa said. "So if we know the composition very well of the sun, we basically understand the starting composition of the initial solar nebula."
The 1,400-pound Genesis probe was launched Aug. 8, 2001, from the Cape Canaveral Air Force Station atop a Boeing Delta 2 rocket.
To collect pristine samples of the solar wind, the spacecraft was fired on a long, looping trajectory that carried it to a point about a million miles toward the sun where the gravity of Earth and its star essentially cancel each other out.
Three months later, Genesis slipped into a so-called halo orbit around the Lagrange 1, or L1, point where it remained for 27 months, exposing its collectors to the passing solar wind, before beginning the trip home in late April. Earlier today, the sample container separated from the main body of the spacecraft and made a pinpoint re-entry. And then, something went wrong.
The collectors measured about one yard square and were each made up of 55 hexagonal tiles about four inches across. The tiles, in turn, were made up of various materials, ranging from silicon and germanium to artificial diamond. The materials were selected because of their ability to capture specific elements in the solar wind.
A key goal of the Genesis mission was to precisely measure the abundances of three isotopes of oxygen: Oxygen-16, the most common form, with eight protons and eight neutrons; oxygen-17, with nine neutrons; and oxygen-18, which has 10 neutrons.
Scientists already understand the relative abundances of these isotopes in asteroids, Earth, the moon and Mars. But the ratio of the isotopes in the sun, and hence the original solar nebula, is not well understood.
Da Space.com (http://www.space.com/news/genesis_captured_040908.html):
Space Probe Fails to Deploy Chute, Slams into Earth
By Leonard David
Senior Space Writer
posted: 08 September 2004
12:04 pm ET
DUGWAY PROVING GROUND, UTAH -- A NASA spacecraft spun out of control and crashed into the Utah desert this morning, putting a disastrous end to a years-long mission to bring back samples of the Sun.
The probe was supposed to deploy a parachute and be snagged by a helicopter for safe recovery.
The capsule, carrying tiny particles from the solar wind that scientists were eager to study for the first time, was half buried in the sandy surface and "appeared to be intact," said a NASA mission controller.
Closer inspection showed the flying-saucer-shaped ship had cracked in two, however.
100 mph impact
Genesis and its solar cargo slammed into the ground at about 100 mph, said Chris Jones, a spokesperson for NASA. The space agency did not immediately provide any detail on the expected condition of the probe's contents, but scientists are optimistic there will be some particles to recover.
"We've lost something," said Roger Wines, science team flight payload leader from Los Alamos National Laboratory. "Now we'll have to analyze the pieces."
Since its launch in August 2001, the $264 million Genesis mission flew to a point just under one million miles (1.5 million kilometers) from Earth. Once there, the spacecraft deployed sample collectors to "soak up the Sun" -- entrapping particles carried into space by a constantly streaming "solar wind," for return to Earth. The particles were obtained by sets of collectors that were exposed to space over a period of 850 days.
Under blue sky and nearly cloudless conditions here, a mini-squadron of three helicopters took off at about 11:25 a.m. ET, positioning their aircraft in a holding pattern at about 10,000 feet to await the arrival of the descending capsule.
All appeared to be going well.
Out of control
When the helicopters lifted off, Genesis was above the atmosphere, roughly halfway between the United States and Hawaii, screaming toward the planet.
A few minutes before Noon ET powerful radar and visual instruments here at the Test and Training Range spotted the Genesis capsule sliding through the atmosphere over the western part of the country. The probe was spinning 15 times a minute, looking like an out-of-control garbage can or some space boulder as it flew in at high speed.
"I just had a big pit in my stomach," Wines said of watching Genesis plummet toward the ground.
Live video taken from the surface followed the probe all the way down, while NASA officials noted that the parachute had not opened, as planned.
The helicopter crews, including a Hollywood stunt pilot, were to spot the capsule and latch onto it with a long hook. Instead, they landed near the crash site to inspect the damage. But NASA engineers feared the explosive for the parachute might still be alive and ready to fire, so the crews were advised to keep a safe distance.
"That presents a safety hazard to recovery crews," Jones said.
Hopes dashed?
Scientists hoped the solar samples, considered among the most primordial bits of the solar system available, would help them unravel mysteries surrounding the formation of the nine planets and the central star they orbit.
Being the first U.S. sample return mission since Apollo 17 moonwalkers brought back lunar samples in 1972, Genesis was to be a trailblazer for another return sample effort, the NASA Stardust mission. Stardust is slated to make a Utah parachute landing on January 15, 2006.
A slogan spotted on one of the mission control computers at the Utah ground facility this morning proved prophetic. It read, "Genesis: Utah or Bust."
http://www.space.com/images/h_genesis_plummet_02.jpg
The Genesis space capsule plummeted through the sky, wobbling like a frisbee when its parachutes failed to deploy after reentry into the Earth's atmosphere. Credit: NASA TV.
http://www.space.com/images/h_genesis_impact_02.jpg
The Genesis sample return capsule slammed into the desert floor after its droge chute and parafoil failed to deploy upon reentry. The probe is carrying samples of solar wind and crashed into the ground at the Utah Test and Training Range. Credit: NASA TV.
http://www.space.com/images/h_genesis_ap_02.jpg
A closeup of the Genesis sample return capsule embedded in the desert floor after slamming into the ground at 100 miles an hour. Its two parachutes failed to deploy after reentry. Credit: AP Photo/NASA TV.
peccato, chissa se riusciranno cmq a prendere qualcosa di quei pochi microgrammi di polvere.
THURSDAY, SEPTEMBER 9, 2004
0305 GMT (11:05 p.m. EDT Wed.)
Genesis' science canister loaded with the solar wind samples was transported by helicopter from the impact site to a holding area next to a specially constructed cleanroom on the Utah base, NASA announced late Wednesday.
Foil wrapping was removed from the canister and dirt brushed off before the canister was moved into the cleanroom for analysis of the contents. The Genesis team will begin examining the canister on Thursday morning.
The capsule plunged into Earth's atmosphere at 1552:47 GMT (11:52:47 a.m. EDT) and entered the preplanned entry ellipse in the Utah Test & Training Range as predicted. However, the drogue chute and parafoil failed to deploy, causing the craft to smack the ground at a speed of 193 miles per hour. The impact occurred near Granite Peak on a remote portion of the range. No people or structures were anywhere near the area, NASA said.
Meanwhile, NASA Administrator Sean O'Keefe released a statement on Wednesday's landing mishap:
"We're encouraged by the news out of Utah, despite the hard impact landing of the Genesis Sample Return capsule. The spacecraft was designed in a way to give us the best chance at salvaging the valuable science payload should we suffer a landing like the one we witnessed today.
"Our re-entry plan was based on safety, and the choice of Dugway was intentional. While today's developments may be disappointing to some, I know the entire NASA family is thankful no one was injured.
"Exploration of the heavens is not an easy task. Our ability to travel throughout our solar system is limited, whether by human tended or robotic craft. Genesis was an experiment to journey far from home and return with new clues and possible answers to some of the fundamental questions regarding the origin of our universe.
"With each new mission, we push the frontiers of our knowledge and technology, and we're hopeful that what appears to be a setback, will eventually return some impressive results. After all, this isn't an Olympic event where we're awarded a medal for a perfect landing. Our final achievement will be measured by what we've learned over the entire three- year mission.
"Our scientists and engineers across NASA and our Jet Propulsion Laboratory are the best in the world. We will find out what happened to Genesis, and we'll continue our quest to accomplish the goals spelled out in our Vision for Space Exploration."
0345 GMT (11:45 p.m. EDT Wed.)
This collection of pictures recaps the Genesis solar wind sample return capsule making a high-speed impact into the Utah desert floor after its chutes failed to deploy during atmospheric descent from space on Wednesday.
ChristinaAemiliana
09-09-2004, 12:43
Brutto colpo per la NASA, proprio ora che cercava di rilanciare la sua immagine dopo l'incidente del Columbia.
Ora scendo a pranzo, leggerò con calma dopo...probabilmente ci saranno notizie anche sui giornali di oggi, non li ho ancora visti.
Per dirla in inglese ...
Shit !
:muro: :muro:
Peccato davvero.
Era una missione interessantissima.
Andata in malora per un paracadute che probabilmente era tra le componenti meno tecnologiche di tutta la missione..:(
nicovent
09-09-2004, 15:25
Ecco il video: Quick Time 6,4 MB (http://www.focus.it/fileflash/filmati/genesis.mov)
ChristinaAemiliana
09-09-2004, 15:26
Mi ricorda il caso del satellite tethered, perso perché si ruppe il filo che lo teneva al "guinzaglio"...:p
Cmq tante volte sono i componenti più banali a dare problemi...ci si presta meno attenzione...:)
infatti, cmq c'è anche da dire che, a fronte di un (probabile) insuccesso, ve ne sono stati anche di successi dopo il disastro del Columbia, la doppia missione robotica marziana dei Mars Exploration Rover e Cassini, che sta dando grandi risultati, per ora... anche se, alla luce del problema di ieri, qualche preoccupazione ulteriore per i prossimi "atterraggi" c'è, anche se non dovrebbe ripetersi il problema al sistema di innesco dei parcadute... :sperem:
ChristinaAemiliana
09-09-2004, 17:02
Speriamo, sarebbe un colpo di sfiga indecente se succedesse di nuovo qualcosa...:sperem:
Certo che le variabili in una missione così complessa sono innumerevoli...
appunto, e come hai fatto notare giustamente tu, spesso i problemi nascono dagli apparati meno tecnologici, se così si può dire...
Cmq Stardust, la sonda che dovrebbe riportare tra 15 mesi un contenitore con la "polvere" della cometa Wild-2, ha lo stesso identico sistema di paracadute stabilizzatore in fase di alta velocità + parapendio, e questa missione doveva servire anche come test... :D
Anche se nel caso di Stardust non è previsto il recupero della sonda in aria da un elicottero come nel caso di Genesis, infatti il sistema con aerogel usato per catturare le particelle cosmiche non è cos' fragile come i dischi di titanio, diamante ed oro della missione GENESIS. :)
RiccardoS
10-09-2004, 07:06
occhio a postare quelle foto Gio, 'chè "qualcuno tra noi" :asd: potrebbe spacciarle per qualche navetta di qualche rottinculiano schiantatasi a terra per errore! :asd: :asd:
Si è capito perchè non ha funzionato l'innesco dei paracadute ?
Originariamente inviato da evelon
Si è capito perchè non ha funzionato l'innesco dei paracadute ?
Non ancora, è in corso l'indagine or ora.
certo che il progettista aereodinamico non ha fatto un grande lavoro , ho visto il video e veniva giu' in maniera completamente incontrollata , non mi stupisco che all' inzio una delle possibili ipotesi fosse che il paracadute non avesse funzionato perche' aveva certato di aprirsi mentre la sonda si trovava sottosopra.
Le apollo rientravano in maniera molto piu' ordinata.
Originariamente inviato da Athlon
certo che il progettista aereodinamico non ha fatto un grande lavoro , ho visto il video e veniva giu' in maniera completamente incontrollata , non mi stupisco che all' inzio una delle possibili ipotesi fosse che il paracadute non avesse funzionato perche' aveva certato di aprirsi mentre la sonda si trovava sottosopra.
Ehmm... e' una capsula, e le capsule devono avere quella forma se vuoi farle resistere alle altissime temperature del passaggio in atmosfera a quasi 30k km/h!
La capsula ha cominciato a roteare a 10 miglia di altitudine, perchè non si è aperto il paracadute stabilizzatore, prima che fosse "sparato" fuori il parapendio per frenare la capsula fino a circa 30 km/h in modo da essere presa in volo.
L'ipotesi che scrivi non l'ho mai sentita, si sono fatte poche ipotesi, e tutte parlavano del malfunzionamento del sistema di innesco o di comando del paracadute, probabilmente l'alimentazione o il sensore di decelerazione (che doveva comandare l'apertura del paracadute a 3G di decelerazione negativa).
Lots of Science Intact in Smashed-Up Genesis Capsule
By Robert Roy Britt
Senior Science Writer
posted: 10 September 2004
02:13 pm ET
Scientists and engineers are optimistic after having peeked inside the Genesis space capsule, which brought back bits of the Sun but crashed into the Utah desert Wednesday.
The craft was supposed to deploy a parachute and be retrieved in the air by a helicopter. Instead it broke apart on impact. Amazingly, scientists say, much of the contents -- microscopic particles that once rode the solar wind and are now embedded on shattered collector plates -- should be salvageable.
In a teleconference with reporters today, mission officials said contamination is their greatest worry, since desert dirt entered the capsule. They need to retrieve the Sun samples in pristine form. The goal is to learn more about the Sun's composition and the history of the solar system and planet formation.
The team might seek advice on handling the wafer-thin collector devices from the semiconductor industry, said Don Burnett, Genesis principal investigator from the California Institute of Technology.
Surprise
"We should be surprised that we have anything," said Don Sevilla, Genesis payload recovery leader at NASA's Jet Propulsion Laboratory (JPL).
Sevilla said experts are "peeling back the layers of the onion," using a flashlight and a small mirror on a stick to explore inside the fractured, garbage-can-sized capsule. A prime particle-gathering device "appears intact," he said, and another appears to be "in very good condition."
But pieces of the fragile collectors are "strewn about the canister," so scientists are being very methodical about extracting them.
"It is amazing given the amount of breach in the canister just how clean it is inside" Sevilla said. "We're not talking about great clods of dirt."
No timetable has been created for moving the science samples from a Utah facility to a NASA center for ultimate study. Sevilla said engineers are still busy collecting tools to do unexpected "sawing and snipping" that will take place over the weekend.
Genesis, which launched in 2001, carries a $264 million price tag.
The scientists said they were demoralized when they first saw the craft stuck more than halfway into the desert floor. Attitudes have changed.
"The science team is really excited," said Roger Wiens, flight payload leader from the Los Alamos National Laboratory. Wiens expects to "meet many if not all" of the mission's initial goals.
The investigation
Meanwhile, Sevilla said three pyrotechnic devices that were supposed to deploy the parachute system failed to trigger as planned. They have been "safed" to allow study of the capsule.
"None had been fired," he said. "This points to a command and control problem," not to any failure of the parachutes themselves.
NASA also announced today that Michael Ryschkewitsch, director of the Applied Engineering and Technology Directorate at NASA's Goddard Space Flight Center, would lead the Genesis Mishap Investigation Board (MIB) in an effort to determine the exact cause of the disaster. The group is due to report back in mid-November.
The optimistic assessment led one reporter to ask if future sample-return missions might forego the theatrics of using Hollywood stunt pilots to make mid-air retrievals of capsules, and instead simply design the shells to survive a freefall.
"The lessons from this one will affect all future sample returns," said Gentry Lee, a JPL engineer.
ChristinaAemiliana
11-09-2004, 15:36
Quindi un guasto di modo comune...se fosse così sarebbe assurdo, è dal rapporto Rasmussen che in USA sono maestri dell'analisi di sicurezza e non fanno altro che raccomandare ridondanza e diversificazione proprio per evitare episodi di questo genere...
Meno male che se non altro sono riusciti a salvare del materiale di interesse scientifico...ma mi piacerebbe sapere di più su questo guasto...
Se qualcuno vuole ancora saperne di più sul guasto sul sito della missione è disponibile (http://genesismission.jpl.nasa.gov/gm2/news/index.htm) il rapporto della commissione d'inchiesta.
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