Mars Odyssey Update – August 20, 2001

NASA’s 2001 Mars Odyssey spacecraft, now 18.5 million
kilometers (11.5 million miles) from Mars on its way to a
rendezvous with the red planet on Oct. 23, remains in overall
good health. Flight controllers have turned off the Martian
radiation environment experiment after the instrument did not
respond during a downlink session last week.

Following unsuccessful attempts to reset the radiation
instrument, the mission manager and project officials have
decided to form a team to further study the anomaly over the
next several weeks and propose a course of action to recover
the instrument following Mars orbit insertion on Oct. 23.

Managers suggested that the most important thing now is
for the team members to devote their attention to achieving a
successful Mars orbit insertion, a demanding maneuver that
will require a focused team effort over the next few months.

“We have limited information on the nature of the problem
with the radiation experiment. The investigative team will
develop a fault tree containing a list of potential causes for
the behavior,” said David A. Spencer, Odyssey’s mission
manager at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.

The spacecraft’s other science payloads are working as
expected. The thermal emission imaging system is made up of
an infrared imager and a visible camera, and the gamma ray
spectrometer instrument package contains a gamma ray sensor,
neutron spectrometer and high-energy neutron detector.

On Friday, Aug. 17, the team opened and closed the
valves in the spacecraft’s main engine to verify that it is
working properly prior to Mars arrival. On Oct. 23, the main
engine will burn for 24 minutes so the spacecraft will be
captured into orbit around the planet.

Today, Odyssey is traveling at 24 kilometers per second
(54,600 miles per hour) relative to the Sun.

The 2001 Mars Odyssey mission is managed by JPL for
NASA’s Office of Space Science, Washington, D.C. JPL is a
division of the California Institute of Technology in
Pasadena. The Odyssey spacecraft was built by Lockheed Martin
Astronautics, Denver. NASA’s Johnson Space Center, Houston,
built and manages the Martian radiation environment
experiment. The thermal emission imaging system is managed by
Arizona State University, Tempe, and the gamma ray
spectrometer is managed by the University of Arizona, Tucson.