Nov. 13, 2006 — For scientists planning a trio of new space missions, the hard part
already is over: The probes are safely in space.
Idling in orbit since their complementary comet missions,
NASA's Deep Impact and Stardust space probes may soon have new leases
on life.
The space agency last week approved funding to develop two
follow-on missions for Deep Impact, which blasted a projectile into
the core of Comet Tempel-1 in July 2005, and one extension flight for
Stardust, which this year returned samples of Comet Wild-2 that were
collected during a January 2004 close encounter.
Deep Impact, Take Two
If the new missions are approved, Deep Impact would use its three
working science instruments and remaining fuel for an extended flyby
of Comet Boethin in December 2008.
"This mission is a very cost-effective way to provide new results
that can be directly compared to the Deep Impact findings," said
project lead scientist Michael A'Hearn, with the University of
Maryland.
Researchers have been surprised by the diversity of the few
comets studied to date — an indication the icy objects, which are
believed to be leftover remains from the formation of the solar
system, evolved differently.
"Even on Tempel 1, the comet we've imaged the best, there is shocking
variability in its surface," A'Hearn said.
Scientists want to know what comets originally looked like and what
happened to them as they traveled through space. The information is
key to understanding if comets did indeed deliver the organic
molecules that ultimately gave rise to life on Earth, as many
researchers suspect.
En route to its new target, the spacecraft would have another mission
unrelated to comets. A team of scientists led by Drake Deming at
NASA's Goddard Spaceflight Center in Greenbelt, Md., wants to use
Deep Impact to look for Earth-like planets around stars in other
solar systems.
The scientists would use Deep Impact's electronic camera to measure
photons of light radiating from stars already known to have giant
Jupiter-class planets in orbit.
The instrument is sensitive enough to
not only detect the big planets' passage in front of their mother
stars, but even relatively tiny, Earth-like worlds.
If approved, the two Deep Impact extension missions would cost NASA
up to $70 million — less than a quarter of the original mission cost.
The contracts recently awarded were for $250,000 per project.
