Mars Odyssey Ready for Work
(From the March/April 2002 issue of StarDate
magazine)
After surfing through the Martian atmosphere for almost three months
and refining its orbit for a month more, 2001 Mars Odyssey was scheduled
to begin its scientific mission in late February: sniffing out Martian
water, mapping the composition of the Martian surface, and sampling
the radiation around the planet.
Odyssey entered orbit around Mars October 23. To save weight, though,
it didn’t carry enough fuel to achieve its final mapping orbit.
Instead, the craft dipped into the outer fringes of the Martian
atmosphere, using its wing-like solar panels to “surf”
to a lower altitude. Odyssey completed this aerobraking maneuver
in January. The craft then fired its small maneuvering thrusters
several times in January and February to tweak the orbit.
The craft’s most intriguing mission is the search for Martian
water — past and present. Water is rare on Mars today. Some
is frozen in the planet’s polar ice caps or mixed with the
soil as permafrost, and a bit more is found in the atmosphere as
water vapor. Mars Global Surveyor, which will work in tandem with
Odyssey, has also found evidence that liquid water sometimes bursts
to the surface from underground reservoirs. Odyssey’s instruments
will peer just below the surface for the chemical “fingerprint”
of hydrogen, which may indicate the presence of such reservoirs.
Odyssey also will search for geologic “hot spots” that
might warm pools of water below the surface.
In addition, Odyssey will hunt for clues to help scientists piece
together the history of water on Mars. Global Surveyor and other
spacecraft have found extensive evidence that Mars was once much
wetter than today, including possible river channels and an ocean
coastline. But there’s little indication of where all the
water went.
Odyssey’s main mission will last for two and a half years.
After that, it will serve as an orbiting relay station for two American
rovers and a European lander scheduled to arrive at Mars in 2005.
— Damond Benningfield
|
Contact StarDate | About StarDate | Friends of McDonald | Sign up for Sky Tips
