for National Geographic News
On Friday, a NASA spacecraft will make a pass on the wild side.
Flying at five times the speed of a rifle bullet, the Stardust spacecraft will pass through a cloud of dust particles swirling off comet Wild 2, which is zipping through space some 242 million miles (389 million kilometers) away on the far side of the sun.
Using a tennis-racket-shaped collector filled with gaseous jelly, the spacecraft will snare hundreds of comet particles and fly them back to Earth. If all goes according to plan, the collector will parachute down to the Utah desert in January 2006.
Scientists believe comets are the remnants of exploded stars, leftover planetary building blocks that may hold secrets to the origins of life. Stardust will allow scientists for the first time to study unaltered bits of this primordial matter.
"One of the reasons we want to go to a comet is there is so much we don't know about comets," said Thomas Duxbury, program manager for the Stardust mission at NASA's Jet Propulsion Laboratory in Pasadena, California.
The 770-pound (350-kilogram) spacecraft will zoom to within 186 miles (300 kilometers) of the comet's icy nucleus. In addition to the dust collector, a camera onboard the spacecraft will snap close-up photos of the chunk of gravel and ice and transmit them to Earth.
Second "Biggie"
Getting Stardust to Wild 2 (pronounced "vilt two") and back to Earth is an epic seven-year journey. Friday's flyby of Wild 2 is the second of what Duxbury refers to as the "three biggies" of the adventure.
The first was the spacecraft's launch from Cape Canaveral, Florida, on February 7, 1999. The third will be the return of the capsule containing the comet dust to the Utah desert in 2006.
"We are at the second of the three, and I kind of laugh at how I'm really feeling," said Duxbury. "We've been working hard for the last month. The team's tired. Even though we're quite excited—underneath the surface is excitement—we are getting worn out."
Duxbury and his team have sacrificed their Christmas and New Year's holidays to do everything they can to ensure the Wild 2 flyby goes according to plan.
Using a steady stream of images of the comet taken by the spacecraft's camera, engineers are guiding Stardust in for the encounter.
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