CNN.com: Stardust capsule lands in Utah

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http://www.cnn.com/2006/TECH/space/01/15/stardust/index.html

Stardust capsule lands in Utah

Scientists hopes for clues to formation of solar system

(CNN) -- A capsule carrying dust particles from the tail of a comet parachuted to Earth on Sunday, and elated NASA scientists were eager to examine the samples for clues about how the solar system formed.

The Stardust mission capsule landed two minutes ahead of schedule at the Air Force's Utah Test and Training Range southwest of Salt Lake City.

"We traveled almost 3 billion miles in space," principal investigator Don Brownlee said from nearby Dugway Proving Grounds. "We visited a comet, grabbed a piece of it, and it landed here this morning. It's an incredible thrill."

The canister containing the samples was taken to a "clean room" at the proving grounds; it will be shipped to NASA's Johnson Space Center in Houston, Texas, this week.

Complete analysis of the material, some of which will be conducted on the molecular level, should take years.

Brownlee has said scientists would have some results, such as the number of particles recovered, within days and more detailed findings within weeks.

The material, expected to be about a thimble full, must be separated from a substance called aerogel, used to help trap the particles.

Aerogel is a strong, lightweight silica glass that is 99.8 percent air and looks like frozen smoke. (What is aerogel)

Brownlee has likened the discovery process to the ongoing study of rocks brought back from the moon.

"The last Apollo mission was 1972. And people are still discovering very exciting things on the Apollo samples," he said. "Samples are a resource that are unending. And so unless we consume all the samples, they will certainly be studied decades from now."

Safe landing

NASA's last sample return mission did not go as planned. In 2004, the parachutes on the Genesis spacecraft didn't open, and it crashed into the ground at full speed.

Stardust appeared to land without a hitch.

Applause swept the mission control room at the Jet Propulsion Laboratory (JPL) in Pasadena, California, as "All stations, we have touchdown!" was announced at 3:10 a.m.

"We pushed about every frontier you can think of," said Project Manager Tom Duxbury. "We went half way to Jupiter on solar cells. Coming back into Earth faster than anything has ever done before. So many, many things that we did in this little project."

Saturday night, the spacecraft flew by Earth after nearly 3 billion miles traveled, and released the 100-pound capsule containing the samples. It entered the atmosphere over the Pacific Ocean, traveling almost 29,000 miles per hour, and crossed over Oregon and Nevada on its way to its landing zone on the Utah salt flats. (Watch how cosmic duster collector was to make its return -- 1:57)

Skywatchers in Nevada saw the capsule streak across the sky, officials at JPL mission said.

At 105,000 feet, a small parachute deployed to begin to stabilize the craft, and at 10,000 feet the main parachute opened to bring it in for a soft landing. Because of the dark sky, NASA tracked the capsule using infrared cameras and helicopters found the capsule once it landed.

Nearly 7-year voyage

Launched in 1999, Stardust orbited the sun on a long intercept course with the comet Wild-2 (pronounced Vild-two).

On January 2, 2004, it flew through the comet's tail, collecting bits of dust in a tennis racket-shaped collector filled with aerogel.

Brownlee compared the process to a police ballistics test.

"You know, when they want to test a bullet, they shoot it into a box full of cotton to capture it, because it is traveling at high speed. And we are essentially doing that," he said. "Except instead of using a box of cotton, we're using this very low density aerogel, so the particle goes into the aerogel and stops."

Scientists say comets are icy, rocky debris left over from the beginning of the solar system 4.5 billion years ago. They expect analysis of the Stardust samples will help them better understand how the planets formed and evolved.

"The fundamental reason for this mission is that we are collecting what we believe are the best preserved samples of the formation of our solar system and they are preserved because they formed these comet bodies beyond the major planets out beyond Neptune," Brownlee had told CNN.

"So we're just using the comet as a storage device," he added.

Wild 2 is thought to come from the Kuiper Belt, a band of debris that orbits the sun beyond Neptune.

Stardust has transmitted photographs and other measurements that provided some valuable data.

"The appearance of the nucleus of this comet was kind of surprising, and different from other comet nuclei that have been recording in spacecraft type detail, so that was quite exciting," David Jewitt, an astronomer at the University of Hawaii, said. Jewitt and astronomer Jane Luu discovered the Kuiper Belt in 1992.

Jewitt said that Kuiper Belt objects appear as faint, unresolved points of light, even in the world's largest telescopes. He said astronomers can count them and track their orbits and even learn some things about their surface composition, but they are too far away to learn about their geography.

"The dust that it hopefully picked up in the aerogel collectors in some sense is a sample of materials from the Kuiper Belt so that's very exciting, too, because we don't have the technology to go out to the Kuiper Belt grab some stuff and then come back with it. It's just too hard to do," Jewitt said.

CNN's Kate Tobin and David E. Williams contributed to this report.

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Fascinating. What was just as interesting as the space mission was the use of the aerogel to capture the particles. If you didn't click on that link, here's a picture of it holding up some crayons over a flame: