From Lori Stiles, UA News Services, 520-621-1877

Mars Odyssey today is a step closer toward its mission to map the Red
Planet.

Odyssey is carrying the Gamma Ray Spectrometer (GRS), built under the
direction of Professor William V. Boynton at the University of Arizona Lunar
and Planetary Laboratory.

The GRS is a suite of three instruments: the Gamma Subsystem, built by the
UA; the Neutron Spectrometer, built by Los Alamos National Laboratory; and
the High Energy Neutron Detector, built by the Space Research Institute,
Moscow.

All three GRS component instruments operated as expected during the 11-month
cruise to Mars.

The UA’s Gamma Subsystem has been in a stowed, door-closed configuration
during the flight to Mars. The stowed, door-closed configuration allowed the
UA team to maintain warm temperatures required to protect the gamma
subsystem.

The UA researchers successfully opened the door at 11 p.m. yesterday to
allow the detector to cool to its very cold operational temperature of minus
138 degrees Celsius (minus 216 degrees Fahrenheit). The detector will begin
collecting gamma rays at this temperature.

"I am really excited about finally getting to see real Mars data," Boynton
said this morning. "I started this project in 1985, and now we are down to
just hours before we see the results. I can imagine it must be like giving
birth, except here we have a 17-year gestation period."

Bill Feldman of Los Alamos National Lab, head of the Neutron Spectrometer
experiment, said, "I am so excited, I can hardly restrain myself!"

Missions operations team members Michael Ward and Kris Kerry said they are
"exhausted, optimistic, and very excited."

The GRS gamma sensor head will remain in this stowed, door-open
configuration for several months, measuring the background gamma rays
emitted by the Mars Odyssey spacecraft itself. At the end of this
calibration period, researchers will deploy the sensor head on a 6-meter
boom. Once the GRS is in its deployed, open-door configuration, the team
will begin collecting science data for mapping the elemental composition of
Mars.

Boynton and other Mars Odyssey scientists will detail their science
objectives Friday, March 1, at news conference to be telecast from the NASA
Jet Propulsion Laboratory in Pasadena, Calif. For more about the news
conference, contact Mary Hardin of JPL Media Relations at 818-354-5011, mary.a.hardin@jpl.nasa.gov