Andromeda Strain!

NASA Capsule Carrying Comet Dust Lands

By Guy Gugliotta
Washington Post Staff Writer
Sunday, January 15, 2006; 2:06 PM


After flying 2.9 billion miles and seven years, NASA's Stardust space capsule parachuted gently to the floor of Utah's high desert today, carrying dust collected nearly two years ago from a comet orbiting the sun beyond Mars.

The Stardust return capsule, shaped like a landmine and only 32 inches across, bounced five times and came to rest in the chill, early morning darkness at the U.S. Army's Dugway Proving Ground.

Its arrival at 5:10 a.m. (EST), elicited a round of cheers from the Dugway recovery team and from mission controllers hundreds of miles away at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"All stations, the main chute is open, and we're coming down slow," Project Manager Tom Duxbury said over the mission's audio loop, and minutes later delivered the news that "okay, we're on the ground."

Helicopter crews collected the capsule and flew it to a small, makeshift "clean room," where handlers unscrewed the capsule's back-shell to remove a canister holding thousands of tiny particles of comet dust trapped in a spun glass-like material called aerogel.

After purging the canister with nitrogen to prevent contamination from Earth's atmosphere, the Dugway team prepared it for transfer to NASA's Johnson Space Center and a special laboratory set up to examine the samples.

While the aerogel probably holds less than a teaspoon of dust from comet Wild 2, it will be enough to keep platoons of scientists busy for years. Comets, migrants from the chill reaches of deep space beyond Neptune, are composed of ice, dust and debris virtually unchanged since the birth of the solar system 4.5 billion years ago.

"It's hard to describe what it feels like," said Stardust lead scientist Don Brownlee, from the University of Washington at Seattle. "It's an incredible thrill," he said at a televised news conference. "We have [completed] a mission to collect the most primitive materials in the solar system."

Stardust's picture-perfect landing concluded the first-ever mission to bring comet material back from outer space. It was also the latest in a series of innovative and inexpensive --Stardust cost $168.4 million--missions to smaller targets in the solar system.

Last July, NASA's Deep Impact dropped a projectile in the path of a comet to analyze the debris plume triggered by the explosion, and in November the Japanese Aerospace Exploration Agency landed a spacecraft on the surface of a tiny asteroid.

Stardust launched from Cape Canaveral Air Force Station Feb. 7, 1999 and rendezvoused with Wild 2 on Jan. 2, 2004 when the comet was 242 million miles from Earth in orbit beyond Mars.

The spacecraft carried a tennis racket-shaped particle collector fitted with about 100 aerogel-filled compartments to trap particles from Wild 2's "coma," the cloud of dust and debris that surrounds a comet as it is heated by the sun. Brownlee said the biggest particles his team expected to harvest are about 0.04 inches in diameter, while most will be between 10 per cent and 20 per cent as wide as a human hair.

The return trip took a little over two years, punctuated by some unease after parachutes failed to deploy on another spacecraft with a re-entry configuration similar to Stardust's. Careful analysis of the Stardust blueprints and pre-flight tests, however, showed that the parachute devices were properly installed.


"We knew we were a little more hardy [than the earlier spacecraft], and we knew we could land hard," Duxbury told reporters. Still, he added, "we breathed a sigh of relief when the drogue parachute opened."

Controllers on Jan. 13 ordered a 58.5 second "burn" to put Stardust in final alignment so the capsule would hit a tiny "window" in the Earth's atmosphere that would result in a safe landing. In all, Stardust's round-trip covered 2.9 billion miles.

At 12:57 a.m. Saturday, Stardust released the 101-pound return capsule for re-entry in the Earth's atmosphere four hours later, about 410,000 feet over California near the Oregon border. At that point the capsule was traveling at 29,000 miles per hour, faster than any spacecraft in history.

In what he described as "the most spectacular part of the mission," Brownlee and several colleagues from the Dugway recovery team stepped outside to watch Stardust come home: "It was reddish, like Mars," Brownlee said. "It just kept getting brighter and brighter."

Duxbury followed the descent on infrared cameras, reporting over the audio loop as events unfolded. Suddenly, at 5 a.m. (EST) the capsule disappeared from the camera image.

"We breathed real easy then, because we knew the drogue chute had opened," Duxbury said later. The capsule's speed had slowed so abruptly that the camera had outraced it: "We're under drogue control," Duxbury said. "We're looking good." At 5:05 a.m., the main parachute opened with the capsule at an altitude of 10,000 feet, slowing the descent still further.

And five minutes later it was on the ground. Three helicopters raced to find it, not an easy task in the pitch darkness of a stormy winter night at Dugway. Winds had carried the capsule about five miles north of the expected landing zone.

It wasn't until 5:43 a.m. that one of the helicopters reported spotting the main parachute, separated from the capsule so it winds would not drag it across the desert floor. But it wasn't until 5:54 a.m. when Duxbury reported that the recovery team had "located the item," provoking one final round of cheers.

http://www.washingtonpost.com/wp-dyn/content/article/2006/01/15/AR2006011500124_pf.html