Stardust Memories

NASA's Stardust sample return capsule is set to go on display next week at the Smithsonian's Air and Space Museum in Washington – giving the public their first chance to see the only man-made object to ever travel beyond the moon into the solar system and then return to Earth.

The goal of the Stardust mission was to return particles of dust from a comet to Earth.  Comets are icy debris left over from the formation of the solar system 4.5 billion years ago, and scientists were itching for a sample to study.  Comets pass by Earth regularly on long, elliptical orbits of the sun, so it would not be that difficult to send a spacecraft on an intercept course.  But getting a sample back...well, that was the challenge.  And engineers came up with an audacious plan.

After launching in 1999, the spacecraft looped through the solar system on a long rendezvous course with comet Wild 2 (pronounced Vild-2).  In January 2004, Stardust  passed through its tail, just 150 miles from its nucleus, and extended a tennis-racket shaped collector filled with a substance called aerogel.  Aerogel is an extremely light, soft, porous material that was used as a capture media for the tiny dust grains from the comet.

Once the sample was safely on board, Stardust turned for home.  On January 15, 2006, the spacecraft shot past Earth and jettisoned the sample return capsule with pinpoint accuracy.  It hit the atmosphere going nearly 29 thousand miles per hour,  rocketed across the sky over the Northern Pacific Ocean, the U.S. Pacific Northwest, and finally parachuted to landing on the empty salt flats of the Utah Test and Training Range.

Check out this SUPER COOL MOVIE of the re-entry shot from a NASA DC8 Aircraft.

Final odometer reading for the sample return capsule:  three billion miles.

Mission scientists say the samples have been a bonanza.  They had expected to find a lot of material in the comet's tail that originally formed around other stars (hence the name Stardust), but this has turned out to be only a minor component.    What they have found is a mixture of crystalline minerals that they believe were formed at different times in the history of the solar system and at  temperature extremes.  Some of the icy components come from the extreme edges of the solar system  where comets spend most of their time.  But other material was apparently formed deep in the super-hot inner regions of the primordial solar system and was then ejected out beyond the orbit of Neptune.   They have detected particles of a material called Inti (named after the Incan sun god)  that is thought to be the earliest solid material formed in the solar system.

While the sample return capsule will now be showcased in the Smithsonian, the Stardust mother ship is still in space and recently got a new assignment.  The mission is called Stardust-NExT and will revisit comet 9P/Tempel 1, which was the focus of NASA's Deep Impact Mission back in 2005.  That comet has since rounded the Sun, and the goal of Stardust-NExT will be to see how the close approach to our fiery star has altered it.

Kate Tobin, Sr. Producer, CNN Science & Tech

Filed under: NASA • Space