An artist's conception shows a close-up look at NASA's comet-hunting Deep Impact spacecraft.
Two NASA probes well past their prime have a fresh lease on life and new missions ahead, the space agency announced Tuesday.
The motherships for NASA?s completed Deep Impact and Stardust missions - which smacked one comet and returned samples from another to Earth, respectively - are being retargeted for new science through about 2011.
?These mission extensions are as exciting as it gets,? said Alan Stern, NASA?s associate administer for the agency?s Science Mission Directorate, in a statement. ?They will allow us to revisit a comet for the first time, add another to the list of comets explored and make a search for small planets around stars with known large planets.?
By using veteran spacecraft already in space, researchers can complete the experiments about 15 percent the cost of completely new? missions, Stern said.
After the comet crash
NASA tapped Deep Impact?s remaining Flyby mothership, which successfully unleashed its Impactor probe to crash into the Comet Tempel 1 on July 4, 2005, for two new science missions, though only one includes another comet.
The spacecraft, which is about the size of a mid-size sport utility vehicle and carries two cameras, will be recycled into NASA?s EPOXI mission aimed at two science objectives.
Under EPOXI, the Flyby vehicle will perform the Deep Impact Expected Investigation (DIXI) to swing by the unexplored Comet Boethin on Dec. 5, 2008 in an effort to recoup comparative data lost with the 2002 failure of NASA?s COmet Nucleus Tour (CONTOUR) mission.
A second science experiment, dubbed Extrasolar Planet Observation and Characterization (EPOCh), calls for Flyby to turn its camera eyes onto stars harboring known giant planets to watch as the extrasolar worlds transit across the faces of their stellar parents. The experiment, researchers hope, will help identify possible rings and moons around the large planets, as well as any additional Earth-sized planets nearby as Flyby heads for its rendezvous with Comet Boethin.
"EPOXI is a wonderful opportunity to add to our growing body of knowledge of exoplanets,? NASA chief scientist John Mather, of the agency?s Science Mission Directorate, said in a statement. ?Watching planets go behind or in front of their parent stars can tell us about their atmospheric chemistry."
While the Flyby spacecraft heads off to a new comet, NASA?s Stardust probe will actually revisit Deep Impact?s Tempel 1 target.
Originally launched in 1999, Stardust chased down the Comet Wild 2 (pronounced ?Vilt 2?) for a 2004 rendezvous that swung within 150 miles (241 kilometers) of the icy wanderer. A sample canister aboard Stardust caught tiny pieces of Wild 2 and returned them to Earth in January 2006 while the remainder of the probe continued on through space.
Now the office desk-sized Stardust will perform the New Exploration of Tempel 1 (NExT) mission to take the first look at the comet after its innermost swing past the Sun.
Stardust is due to swing past Tempel 1 in what will be the first ever follow-up comet rendezvous. The spacecraft?s onboard instruments will continue mapping efforts for Tempel 1 and, researchers hope, shed new light on regions of the comet?s nucleus that may have flowed like liquid or powder according to Deep Impact images.
The NExT flyby past Tempel 1 is slated for Feb. 14, 2011.
The mission extensions for both Deep Impact and Stardust missions are part of NASA?s Discovery program like their original assignments.
- VIDEO: DEEP IMPACT: 'To Poke a Comet'
- Special Report: NASA?s Deep Impact Smacks a Comet
- Full Circle: NASA's Stardust Probe Returns Home with Comet Samples