Comet Dust Capsule Reaches Earth
A space capsule carrying comet dust plummeted through the Earth's atmosphere early Sunday for a target landing in the Utah desert.
It's the first time a spacecraft has flown into deep space and brought back tiny fragments of a comet. Most of the individual granules are so small that a microscope is required to study them.
The Stardust spacecraft released the shuttlecock-shaped capsule late Saturday at 69,000 miles from Earth, and remained in permanent orbit around the sun.
"It's an absolutely fantastic end to the mission," said Carlton Allen of NASA's Johnson Space Center.
A helicopter recovery team was headed to the landing site to retrieve the capsule and transfer it to a clean room on the base. It will be flown later this week to the Johnson Space Center in Houston where scientists will unlock the canister containing the cosmic particles.
Once opened, they will find the microscopic bits trapped in a porous, pale-blue smokelike material made up of 99.8 percent air that was used to snag the dust in space.
The free-falling capsule hurtled toward Earth and penetrated the atmosphere at 29,000 mph, making it the fastest man-made probe to return. It experienced peak heating a minute after entry with the temperature on its protective heat shield spiking to 4,900 degrees.
Comets are frozen bodies of ice and dust that formed soon after a gaseous disk collapsed to create the sun and planets 4.6 billion years ago. Comets formed from what was left over, and studying them could shed light on the solar system's birth.
The cosmic samples were gathered from comet Wild 2 in 2004 during Stardust's seven-year journey. The spacecraft used a tennis racket-sized collector mitt to snatch the dust and store them in an aluminum canister.
The mission, managed by NASA's Jet Propulsion Laboratory, cost $212 million.
Nerves were on edge as scientists anxiously awaited the return of Stardust.
During its mission, the Stardust captured comet dust, collecting a pay load that will barely fill a teaspoon – and yet the incredibly tiny samples were swirling about four and a half billion years ago, reports CBS News correspondent Jerry Bowen.
Scientists believe studying comets could shed light on how the solar system formed.
Memories of the ill-fated 2004 Genesis landing, in which the space probe's parachutes failed to open, are still vivid.
Scientists later found that gravity switches installed incorrectly caused the failure. Despite the mishap, they were able to salvage the tiny cosmic samples for study.
Afterward, engineers performed a thorough check on Stardust's systems and feel certain that it won't suffer the same fate as Genesis.
"They built this thing like a tank. They do believe that even if the parachute system failed, that they could still recover these samples," said CBS News space consultant Bill Harwood .
"I don't think you can ignore the Genesis situation. You just have to embrace it and apply the lessons learned from it," said Ed Hirst, mission system manager at NASA's Jet Propulsion Laboratory.
Stardust left on a seven-year, 2.9 billion-mile journey that was highlighted by a flyby of comet Wild 2, a jet-black ball of ice and dust that was about 500 million miles away from Earth when the probe was launched in 1999.
The 850-pound Stardust, outfitted with armored bumpers, survived a harrowing blast of debris as it flew past Wild 2 to collect dust in 2004. During its journey, it also captured interstellar dust — tiny space particles believed to be from ancient stars that exploded and died.
Scientists hope the samples will build on their knowledge of comets gleaned by NASA's Deep Impact mission last year, which smashed a probe into a comet, revealing its pristine interior.