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Dust-gathering trip near comet nucleus will end in Utah

SHARE Dust-gathering trip near comet nucleus will end in Utah

One of the most imaginative space adventures ever will land in Utah's western desert, according to NASA. It is Project Stardust, which aims at snatching dust from close to the nucleus of a comet and returning it to Earth.

Mission planners say Project Stardust will launch in February 1999 from Cape Canaveral on a five-year journey to collect a sample from Comet Wild-2 (pronounced "vilt two"). When it returns in January 2006, it will parachute to a landing in the Utah Test and Training Range, maintained by the Air Force in western Utah.The Great Salt Lake Desert was chosen because "it's really flat, (the capsule) should be able to be easily found," said project manager Kenneth L. Atkins of the Jet Propulsion Laboratory in Pasadena. "Since we have just a very small capsule, we thought that having the resources and capability of the Air Combat Command would be good from the standpoint of being able to target and find this thing."

A Delta II rocket will take the lightweight spacecraft on its looping journey to the comet rendezvous. But the first encounter will be with Earth itself: It will perform a slingshot sweep past the planet in January 2001, which will fling Stardust farther into deep space.

When it encounters the comet around Christmas 2004, it will be about 100 miles from the comet nucleus and traveling at a relatively slow rate. A clamshell-shaped collector will extend grids filled with "aerogel" to capture grains of cometary dust. Grains will burrow into the filmy material and get stuck there.

Aerogel is an amazing synthetic material, made by the Jet Propulsion Laboratory, a sort of glass material that is 1,000 times less dense than regular glass.

"I think it's lower-density than a spider web," said Richard Berend- zen, professor of physics and astronomy at American University, Washington, D.C. Berendzen is a director of the Planetary Society, which is involved in the mission planning.

The Jet Propulsion Laboratory's Atkins explains that aerogel is a "very under-dense solid material. It's a kind of glass Jell-O, if you will. . . . The material is 99 percent air. It's probably the least dense thing that anybody knows of."

It is perfect for capturing bits of primordial comet material and interstellar grains of dust, NASA believes.

Comet dust, interstellar dust and comet gasses will be stored in a sample re-entry capsule. After the capsule enters Earth's atmosphere, it will free-fall until it is about two miles above the ground. A parachute will pop out and a radio beacon will begin transmitting its location to watchers, who also will be tracking it by radar.

Says a formal mission plan developed by NASA, the re-entry can be targeted to a footprint of about 37 by 3.5 miles, "appropriate for the Utah Test and Training Range."

"Following touchdown, the SRC (sample re-entry capsule) will be recovered by helicopter or ground vehicles and transported to a staging area at (the Utah Test and Training Range) for retrieval of the sample canister. The canister will then be transported to the planetary materials curitorial facility at Johnson Space Center."

At Johnson Space Center in Houston, samples will be divided among scientists worldwide.

"You've gone millions of miles, for the first time in history, to get such a thing," said Berendzen. "And what you're getting is the original stuff of our solar system, the primordial materials from which we ourselves are made."

In addition to comet material, he said, some of the material in deep space may have come into our solar system from elsewhere.

Is there a chance that Utah will be contaminated by material brought back from a comet? "Zero concern with that," Berendzen said.

"There is a danger with contamination, but not of the Earth. . . . The danger is contamination of the sample. . . . I would view the flip side around - don't you guys (in Utah) contaminate the sample!"