DUGWAY PROVING GROUND, Utah – A space capsule ferrying the first comet dust samples to Earth parachuted onto a remote stretch of desert before dawn Sunday, drawing cheers from elated scientists.
The touchdown capped a seven-year journey by NASA's Stardust spacecraft, which zipped past a comet in 2004 to capture minute dust particles and store them in the capsule.
"It's an absolutely fantastic end to the mission," said Carlton Allen, a scientist with NASA's Johnson Space Center.
A helicopter recovery team located the capsule Sunday and was transferring it to a clean room at the nearby Michael Army Air Field. The capsule will be flown Tuesday to the Johnson Space Center in Houston where scientists will unlock the canister containing the cosmic particles.
Researchers believe about a million samples of comet and interstellar dust — most tinier than the width of a human hair — are locked inside the capsule.
The dust grains are believed to be pristine leftovers from the birth of the solar system, with some of the particles thought to be older than the sun. Scientists hope to slice them into smaller bits and probe them under a microscope to directly learn about their chemical makeup and the processes that shaped the early universe.
The cosmic samples were gathered in 2004 from the comet Wild 2, a frozen body of ice and dust believed to have been formed billions of years ago. The Stardust spacecraft used a tennis racket-sized collector mitt to snag the particles in a porous material and stored them in a capsule.
Early Sunday, that capsule nose-dived through Earth's atmosphere at a record 29,000 mph, the fastest return for a man-man probe.
It appeared as a bright orange fireball as it streaked over the small mining town of Tonopah, Nev., halfway between Las Vegas and Reno, said Ron Dantowitz of NASA's Ames Research Center, who witnessed the capsule's trek.
As it descended toward the desert, the first parachute opened at 100,000 feet, followed by a larger chute, which guided it to a 10-mph landing on the salt flats. NASA officials said the capsule bounced three times before coming to rest on its side.
The landing was a relief for scientists after the 2004 Genesis mission, when the returning craft carrying solar wind particles slammed into the desert and cracked open, exposing the solar atoms to contamination.
Genesis and Stardust were the first robotic retrievals of extraterrestrial material since 1976, when the unmanned Soviet Luna 24 mission brought back lunar rocks and soil.
Launched in 1999, the Stardust spacecraft has traveled nearly 3 billion miles, looping around the sun three times.
In 2004, it beamed back 72 black-and-white pictures showing broad mesas, craters, pinnacles and canyons with flat floors on the surface of Wild 2, a craggy comet that was about 500 million miles from Earth at the craft's launch.
The mission, managed by NASA's Jet Propulsion Laboratory, cost $212 million, and it isn't over. The mothership remains in permanent orbit around the sun, and NASA is considering sending it to another comet or asteroid, said Tom Duxbury, Stardust's project manager.
Stardust's sample return was the latest mission designed to study comets up close.
Six months earlier, NASA sent a probe into the path of an onrushing comet. The high-speed collision with comet Tempel 1 set off a celestial fireworks display in space and exposed the comet's primordial interior.
Scientists have been analyzing the voluminous debris hurled from the comet's belly and are trying to figure out the size of the crater caused by the impact.