NASA’s Mars Odyssey orbiter begins working overtime
today after completing a prime mission that discovered vast
supplies of frozen water, ran a safety check for future
astronauts, and mapped surface textures and minerals all over
Mars, among other feats.
“Odyssey has accomplished all of its mission-success
criteria,” said Dr. Philip Varghese, project manager for
Odyssey at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
The spacecraft has been examining Mars in detail since
February 2002, more than a full Mars year of about 23 Earth
months. NASA has approved an extended mission through
September 2006.
“This extension gives us another martian year to build on
what we have already learned,” said JPL’s Dr. Jeff Plaut,
project scientist for Odyssey. “One goal is to look for
climate change. During the prime mission we tracked dramatic
seasonal changes, such as the comings and goings of polar
ice, clouds and dust storms. Now, we have begun watching for
year-to-year differences at the same time of year.”
The extension will also continue Odyssey’s support for other
Mars missions. About 85 percent of images and other data from
NASA’s twin Mars rovers, Spirit and Opportunity, have reached
Earth via communications relay by Odyssey, which receives
transmissions from both rovers every day.
The orbiter helped analyze potential landing sites for the
rovers and is doing the same for NASA’s Phoenix mission,
scheduled to land on Mars in 2008. Plans call for Odyssey to
aid NASA’s Mars Reconnaissance Orbiter, due to reach Mars in
March 2006, by monitoring atmospheric conditions during
months when the newly arrived orbiter uses calculated dips
into the atmosphere to alter its orbit into the desired
shape.
Odyssey was launched April 7, 2001, and used the same
“aerobraking” technique to shape its orbit during the initial
months after it reached Mars on October 23, 2001. The
spacecraft carries three research systems: a camera system
made up of infrared and visible-light sensors; a spectrometer
suite with a gamma ray spectrometer, a neutron spectrometer
and a high-energy neutron detector; and a radiation
environment detector.
Less than a month after the science mapping campaign began,
the team announced a major discovery. The gamma ray and
neutron instruments detected copious hydrogen just under
Mars’ surface in the planet’s south polar region. Researchers
interpret the hydrogen as frozen water — enough within about
a meter (3 feet) of the surface, if the ice were melted, to
fill Lake Michigan a couple times.
Here are a few of Odyssey’s other important accomplishments
so far:
— As summer came to northern Mars and the north polar
covering of frozen carbon dioxide shrank, Odyssey found
abundant frozen water in the north, too.
— Infrared mapping shows that a mineral called olivine is
widespread. This indicates the environment has been quite
dry, because water exposure alters olivine into other
minerals.
— Findings indicate the amount of frozen water in some
relatively warm regions on Mars is too great to be in
equilibrium with the atmosphere, suggesting that Mars may be
going through a period of climate change. Features visible
near small, young gullies in some Odyssey images may be
slowly melting snowpacks left over from a martian ice age.
— The first experiment sent to Mars specifically in
preparation for human missions found that radiation levels
around Mars, from solar flares and cosmic rays, are two to
three times higher than around Earth.
— Odyssey’s camera system has obtained the most detailed
complete global maps of Mars ever, with daytime and nighttime
infrared images at a resolution of 100 meters (328 feet).
“We’ve accomplished everything we set out to do, and more,”
said JPL’s Robert Mase, Odyssey mission manager. Although an
unusually powerful solar flare in October 2003 knocked out
the radiation environment instrument, Odyssey is otherwise in
excellent health. The spacecraft has enough fuel onboard to
keep operating through this decade and the next at current
consumption rates. The mission extension, with a budget of
$35 million, essentially doubles the science payoff from
Odyssey for less than one-eighth of the mission’s original
$297 million cost.
For more information about Mars Odyssey on the Internet,
visit:
http://mars.jpl.nasa.gov/odyssey
