[meteorite-list] NASA's Mars Odyssey Shifting Orbit for Extended Mission

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 10 Oct 2008 11:08:23 -0700 (PDT)
Message-ID: <200810101808.LAA26785_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.cfm?release=2008-191

NASA's Mars Odyssey Shifting Orbit for Extended Mission
Jet Propulsion Laboratory
October 09, 2008

PASADENA, Calif. -- The longest-serving of six spacecraft now studying
Mars is up to new tricks for a third two-year extension of its mission
to examine the most Earthlike of known foreign planets.

NASA's Mars Odyssey is altering its orbit to gain even better
sensitivity for its infrared mapping of Martian minerals. During the
mission extension through September 2010, it will also point its camera
with more flexibility than it has ever used before. Odyssey reached Mars
in 2001.

The orbit adjustment will allow Odyssey's Thermal Emission Imaging
System to look down at sites when it's mid-afternoon, rather than late
afternoon. The multipurpose camera will take advantage of the infrared
radiation emitted by the warmer rocks to provide clues to the rocks'
identities.

"This will allow us to do much more sensitive detection and mapping of
minerals," said Odyssey Project Scientist Jeffrey Plaut of NASA's Jet
Propulsion Laboratory, Pasadena, Calif.

The mission's orbit design before now used a compromise between what
works best for the Thermal Emission Imaging System and what works best
for another instrument, the Gamma Ray Spectrometer.

On commands from its operations team at JPL and at Denver-based Lockheed
Martin Space Systems, Odyssey fired thrusters for nearly 6 minutes on
Sept. 30, the final day of the mission's second two-year extension.

"This was our biggest maneuver since 2002, and it went well," said JPL's
Gaylon McSmith, Odyssey mission manager. "The spacecraft is in good
health. The propellant supply is adequate for operating through at least
2015."

Odyssey's orbit is synchronized with the sun. The local solar time has
been about 5 p.m. at whatever spot on Mars Odyssey flew over as it made
its dozen daily passes from between the north pole region to the south
pole region for the past five years. (Likewise, the local time has been
about 5 a.m. under the track of the spacecraft during the south-to-north
leg of each orbit.)

The push imparted by the Sept. 30 maneuver will gradually change that
synchronization over the next year or so. Its effect is that the time of
day on the ground when Odyssey is overhead is now getting earlier by
about 20 seconds per day. A follow-up maneuver, probably in late 2009
when the overpass time is between 2:30 and 3:00 p.m., will end the
progression toward earlier times.

While aiding performance of the Thermal Emission Imaging System, the
shift to mid-afternoon is expected to stop the use of one of three
instruments in Odyssey's Gamma Ray Spectrometer suite. The suite's gamma
ray detector needs a later-hour orbit to avoid overheating of a critical
component. The suite's neutron spectrometer and high-energy neutron
detector are expected to keep operating.

The Gamma Ray Spectrometer provided dramatic discoveries of water-ice
near the surface throughout much of high-latitude Mars, the impetus for
NASA's Phoenix Mars Lander mission. The gamma ray detector has also
mapped global distribution of many elements, such as iron, silicon and
potassium, a high science priority for the first and second extensions
of the Odyssey mission. A panel of planetary scientists assembled by
NASA recommended this year that Odyssey make the orbit adjustment to get
the best science return from the mission in coming years.

Increased sensitivity for identifying surface minerals is a key science
goal for the mission extension beginning this month. Also, the Odyssey
team plans to begin occasionally aiming the camera away from the
straight-down pointing that has been used throughout the mission. This
will allow the team to fill in some gaps in earlier mapping and also
create some stereo, three-dimensional imaging.

Odyssey will continue providing crucial support for Mars surface
missions as well as conducting its own investigations. It has relayed to
Earth nearly all data returned from NASA rovers Spirit and Opportunity.
It shares with NASA's Mars Reconnaissance Orbiter the relay role for
Phoenix. It has made targeted observations for evaluating candidate
landing sites.

Mars Odyssey, launched in 2001, is managed by JPL, a division of the
California Institute of Technology, Pasadena, for NASA's Science Mission
Directorate, Washington. Lockheed Martin Space Systems, Denver, is the
prime contractor for the project and built the spacecraft. Investigators
at Arizona State University, Tempe, operate the Thermal Emission Imaging
System. Investigators at the University of Arizona, Tucson, head
operation of the Gamma Ray Spectrometer. Additional science partners are
located at the Russian Aviation and Space Agency, which provided the
high-energy neutron detector, and at Los Alamos National Laboratories,
New Mexico, which provided the neutron spectrometer.

For more about the Mars Odyssey mission, visit:
http://mars.jpl.nasa.gov/odyssey .

------------------------------------------------------------------------

Media contacts: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster at jpl.nasa.gov

Dwayne Brown 202-358-1726
Headquarters, Washington
dwayne.c.brown at nasa.gov

2008-191
Received on Fri 10 Oct 2008 02:08:23 PM PDT