NASA's Stardust probe is set to return to Earth January 15, after successfully gathering particle samples from a comet. The spacecraft's return will mark only the second time NASA has attempted to retrieve a spacecraft sent beyond Earth's orbit. It could also bring new answers to old questions about the origins of life.
After traveling nearly five billion kilometers around the solar system, the Stardust mission is nearing the end of its seven-year journey. If all goes well, the spacecraft will come home with what scientists consider precious cargo: bits of stardust and space particles as old as the universe.
Don Brownlee, the mission's lead investigator, believes the samples will provide enough data to keep scientists busy for decades.
"This is a fantastic opportunity to collect the most primitive materials in the solar system,” said the astronomy professor. “We've collected them and they're only weeks away from landing on Earth. It's a really thrilling time."
The samples were collected two years ago, during a carefully orchestrated flyby with the comet, Wild 2. Passing through the comet's tail, a silica-coated plate, extending from the spacecraft, collected millions of particles to be analyzed.
Project manager Tom Duxbury believes the samples could provide answers to fundamental questions about how life began. "There are many theories regarding the role that comets played in the formation of the Earth, bringing the water that we have to Earth, as well as bringing the chemical building blocks needed for life. We hope to validate some of those theories."
During the flyby, the five meter-long spacecraft also snapped more than 70 high-resolution images and some of the best close-ups yet of a comet's nucleus.
"We've flown by comets in the past with limited instruments on board. This will be the very first time that we actually bring cometary samples back to Earth," said Mr. Duxbury.
But NASA scientists say the mission is not out of danger yet. The last attempt to bring back space particles in September 2004, failed when the Genesis probe, carrying samples of solar dust, crashed into the Utah desert.
Engineers say they've learned some important lessons since then. They're optimistic the Stardust mission will have a more successful outcome when it attempts a similar landing in the Utah desert January 15th.