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The Fiery Return of NASA's Space Dust Cargo
11.29.05
http://www.nasa.gov/centers/ames/research/exploringtheuniverse/stardust.html
The mini, Apollo-like capsule will shoot down through the air at the highest spacecraft re-entry speed into Earth's atmosphere ever, generating extremely high temperatures. The capsule's special carbon-based heat shield, developed at NASA Ames Research Center in California's Silicon Valley, will protect the priceless cargo of comet dust and interstellar grains. During this blistering re-entry, the DC-8 crew will take surface-temperature and shock-radiation measurements of the heat shield as part of it burns away. Shock radiation is light emitted from extremely hot air. Scientists will study this light to learn how hot the capsule gets and what chemical reactions are taking place. These chemical reactions will result from of the violent breakup of air molecules that collide with vapor in front of the speeding capsule.
At the same time as the DC-8 crew is flying its mission, amateur astronomers, willing to endure the cold of the bitter winter, may contribute to the study by simply photographing the incoming capsule, noting their global positions and later providing that information to mission scientists.
One of the goals of the researchers aboard the DC-8 is to measure the capsule's re-entry brightness. Scientists expect it to peak at approximately the brilliance of Venus for roughly 90 seconds. The capsule will be brightest 37 miles (60 kilometers) high over the town of Carlin, Nev., as the spacecraft approaches. This will occur in the early morning cold and darkness on Sunday, Jan. 15, 2006, shortly before the spacecraft parachutes to a landing at 3 a.m. MST. The landing zone is a restricted area – the Utah Test and Training Range, located southwest of Salt Lake City.
"As the observer sees the approaching capsule, it will appear as a point of light," said Peter Jenniskens, principal investigator of the Stardust Sample Return Capsule Re-entry Observing Campaign. Jenniskens is a meteor astronomer at the SETI Institute, Mountain View, Calif. "After it passes the observer, the back of the capsule will be less bright, and it will quickly fade. Each observer will have a different experience," Jenniskens added.