[meteorite-list] Longest-Lived Mars Orbiter is Back in Service (Mars Odyssey)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 27 Jun 2012 16:26:47 -0700 (PDT)
Message-ID: <201206272326.q5RNQmmS003582_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.cfm?release=2012-189

Longest-Lived Mars Orbiter is Back in Service
Jet Propulsion Laboratory
June 27, 2012

Mission Status Report

PASADENA, Calif. -- NASA's Mars Odyssey orbiter has resumed its science
observations and its role as a Mars rover's relay, thanks to a spare
part that had been waiting 11 years to be put to use.

Odyssey's flight team returned the orbiter to full service this week
after a careful two-week sequence of activities to recover from a fault
that put Odyssey into reduced-activity "safe" mode. Odyssey switched to
safe mode when one of the three primary reaction wheels used for
attitude control stuck for a few minutes on June 8, Universal Time (June
7, Pacific Time).

Engineers assessed the sticking wheel as unreliable and switched the
spacecraft from that one to a spare that had been unused since before
the mission's April 7, 2001, launch.

"Odyssey is now back in full, nominal operation mode using the
replacement wheel," said Steve Sanders, lead engineer for the Odyssey
team at Lockheed Martin Space Systems, Denver. Lockheed Martin
collaborates with NASA's Jet Propulsion Laboratory, Pasadena, Calif., in
operation of Odyssey, which has worked at Mars longer than any other
Mars mission in history.

Observations of Mars resumed June 25 with Odyssey's Thermal Emission
Imaging System and its Gamma Ray Spectrometer. As a relay, Odyssey
received data from NASA's Mars Exploration Rover Opportunity today, June
27, and transmitted the data to Earth. Other priority activities include
preparing Odyssey to serve as a communications relay for NASA Mars
Science Laboratory mission.

Odyssey uses a set of three reaction wheels to control its attitude, or
which way it is facing relative to the sun, Earth or Mars. Increasing
the rotation rate of a reaction wheel causes the spacecraft itself to
rotate in the opposite direction. The configuration in use from launch
until this month combined the effects of three wheels at right angles to
each other to provide control in all directions. The replacement wheel
is skewed at angles to all three others so that it can be used as a
substitute for any one of them. Odyssey can also use thrusters for
attitude control, though that method draws on the limited supply of
propellant rather than on electricity from the spacecraft's solar array.

Odyssey is managed for NASA's Science Mission Directorate in Washington
by JPL, a division the California Institute of Technology in Pasadena.
Lockheed Martin Space Systems in Denver built the spacecraft. For more
about the Mars Odyssey mission, visit: http://mars.jpl.nasa.gov/odyssey .

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

2012-189
Received on Wed 27 Jun 2012 07:26:47 PM PDT