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Planetary News: Stardust (2006)Stardust Lands Safe and SoundBy A.J.S. RaylJanuary 15, 2006
Stardust – the world’s first comet sample return mission – landed in windy conditions on the salt flats at the Utah Test and Training Range in Utah at 3:10 a.m. local or Mountain Standard Time / 2:10 a.m. Pacific Standard Time this morning, two minutes early and intact. The first of three helicopters was sent in moments later to begin the recovery operation. Despite having the coordinates, infrared instruments to scan the desert floor, and on and off beacon contact with the capsule, the recovery operations crew had some difficulty homing in on the capsule. The range is large and the capsule small, but within 30 minutes they had locked on the spacecraft, and landed. The second helicopter followed minutes later and the third followed suit minutes after that. Word from the retrieval site around 4:20 a.m.MST / 3:20 a.m. PST was that the capsule had bounced three times and landed on its side. The plan calls for the recovery team to wrap up the capsule and fly it to a clean room at the nearby Michael Army Air Field. There, in the clean room technicians will open the capsule and remove the canister that holds the samples. A press conference is scheduled for 7 a.m local or Mountain Standard Time / 6 a.m. Pacific Standard Time. Any fears that Stardust, a $170-million-dollar NASA Discovery mission, might crash land like its sister mission, Genesis, were laid to rest minutes before touchdown, as the instruments indicated the anticipated decrease in speed following the timepoint when the main parachute was to have deployed. When it was confirmed that the parachute had deployed the mission control room at the Jet Propulsion Laboratory (JPL) erupted applause and cheers. Genesis, which had collected samples of the solar wind, was to have been snatched up by Hollywood stunt helicopter pilots but a improperly installed switch caused the parachute to fail. As a result, the spacecraft “hit hard,” as the jargon puts it, in September 2004 in Utah, not far from where Stardust touched down. Calling it a “great day” for science, Stardust principal investigator Don Brownlee, of the University of Washington, Seattle, said: "With the information we gathered during our encounter with comet Wild 2 in January 2004, Stardust has already provided us with some remarkable science. With the return of cometary samples, we'll be able to work with the actual building materials of the solar system as they were when the solar system was formed." The Stardust samples are the world's first preserved samples of the fundamental building blocks of our solar system that formed 4.6 billion years ago. Since unique chemical and physical data that may hold the record of the formation of the planets and the materials from which they were made are locked within these particles, scientists believe in-depth terrestrial analysis of the cometary samples will reveal not only a lot about comets, but about the earliest history of the solar system, and, perhaps, something about ourselves. The landing was the conclusion of a 7-year, 4.63 billion kilometer (2.88 billion mile) round-trip journey to comet Wild 2 (prounced Wilt two), which took Stardust around the Sun three times, beyond Mars and the asteroid belt -- as far out as half-way to Jupiter, and back in time 4.5 billion years to gather the primitive samples of the solar system from the comet’s nucleus. The mission has succeeded in inspiring ways, leading Stardust Project Manager Tom Duxbury, of the Jet Propulsion Laboratory (JPL), to remark more than once on how “perfectly” the mission was going. In January 2004, Stardust returned stunning images of the nucleus of Wild 2 that it snapped as it passed through the coma, images that almost defied belief, showing that the nucleus had mesas, pit, and craters and looked like nothing else in the solar system, changing the conventional wisdom about comets. And somehow it survived the pummeling it received during that passage, collecting countless particles of comet dust, primitive bits of stuff from which everything, perhaps, in our solar system emerged. "We feel like parents awaiting the return of a child who left us young and innocent, who now returns holding answers to the most profound questions of our solar system,” Duxbury said yesterday. This morning, they must feel like proud parents. Stardust came home – and the mission went out on fire. Traveling at 12.8 kilometers or 8 miles per second, more than 10 times faster than a speeding bullet or fast enough to go from San Francisco to Los Angeles in one minute, at a velocity greater than any human-made object on record, the comet chaser set a new record as the fastest returning spacecraft besting the last fastest return set in May 1969 by the Apollo X command module. That seems remarkable until you consider the number of planetary spacecraft that actually return to Earth are few and far between those that wind up as space junk or in some interminable orbit, or that Stardust is the first project to launch a sample return mission since the Apollo days. Still, some things have changed --Stardust’s final 400,000 kilometers (249,000 miles) took just 16 hours and 27 minutes, whereas the Apollo astronauts spent three days making the same journey. About 15 minutes after the release, the Stardust “mothership” performed a divert burn maneuver that put it into around the Sun. Along for that ride is a microchip that contains the names of all Planetary Society members from around the world at the time of the mission’s launch, the first such collection of names from the public to have made a round trip to space and back. The samples returned this morning by Stardust’s return capsule will be packaged later today for shipment to a special laboratory at the Johnson Space Center (JSC), located just south of Houston, Texas, where the team will further analyze, verify and section the samples. A small portion of the samples will be used to make a preliminary study of the returned material, with the rest to be made available to scientists around the world for research. Now that the team has the samples, they are going to have to search the grids for the comet and interstellar dust particles before they can analyze them. They expect to have some results within the first few days and weeks. All told, Stardust’s interstellar bounty may be small may be but a thimble-full so the task may sound simple enough. But the grains are so few and so tiny that the scientists expect that they will be completely lost within the cracked and imperfect surface of the aerogel collector that has spent 7 years in space. In fact, they expect they will be so embedded that the scientists are asking for the public's help via an Internet-based project called Stardust@home, inspired by the long-running Seti@home. Stardust@home will be a hands-on activity, however, unlike SETI@home where one’s computer processed all the data. Scientists at the Space Sciences Laboratory at the University of California at Berkeley (UCB) will create "movies" of each tiny section of the aerogel collectors -- 1.6 million movies in all. Each of these movies will be sent electronically to volunteers around the world, who will inspect them for the telltale signs of interstellar dust particles. Because no one knows exactly what these dust tracks will look like, the human eye – and good old-fashioned human intelligence – will be better at spotting them than a computer program. Therefore, each volunteer scanner will need to pass a test by spotting tracks made in test samples. The team will also keep scanners vigilant by occasionally throwing into the mix a “ringer” – an artificially made track – to see if volunteers find it. As an official collaborator in the project, The Planetary Society has put out an all-call to recruit users. To be part of be part of Stardust@home, you will need an easily downloadable "virtual microscope" and some basic online training, and a desire to really do the research, according to Bruce Betts, the Society’s director of projects. The public can begin signing up with Stardust@home in mid-March. |
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