http://www.jpl.nasa.gov/news/news.cfm?release=2009-038

Odyssey Flight Team to Check Status of Backup System
Jet Propulsion Laboratory
March 04, 2009

Mars Odyssey Mission Status Report

PASADENA, Calif. -- The team operating NASA's Mars Odyssey orbiter
plans
a procedure next week to address a long-known, potential vulnerability
of accumulated memory corruption.

The procedure requires rebooting the spacecraft's computer. This is
not
a risk-free event, but the Odyssey team and NASA have carefully
weighed
the risks of performing a cold reboot compared with the risk of doing
nothing, and determined that the proper course of action is to proceed
with the reboot.

The chief concern about the potential memory vulnerability stems from
the length of time that the spacecraft has been exposed to the
accumulated effects of the space radiation environment since the last
reboot, which occurred on Oct. 31, 2003.

As an additional benefit, the cold-reboot procedure will demonstrate
whether Odyssey's onboard backup systems will be available should they
ever be required.

"We have lost no functionality, but there would be advantages to
knowing
whether the B side is available," said Odyssey Mission Manager Gaylon
McSmith of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We have
developed a careful plan for attempting to determine that."

In all the years since its April 7, 2001, launch, Odyssey has not
needed
to use its set of spare components. The spares are called the
spacecraft's "B side," which includes an identical set of a computer
processor, navigation sensors, relay radio and other subsystems. To
use
any of them, Odyssey would have to shift to all of them at once from
its
primary set of components, called the "A side."

On March 21, 2007, the B-side spare of an electronic component for
managing the distribution of power, called the high-efficiency power
supply, became inoperable. If it is permanently disabled, then none of
the B side is available for use. Engineers have investigated the
inoperability of the B-side high-efficiency power supply. They
concluded
that the component can probably be made to work properly again by
rebooting the orbiter's computer, although the memory-vulnerability
issue that is the current concern is not directly related to the March
2007 event that affected the power supply.

Odyssey is in the third two-year extension of its mission at Mars.
Some
A-side components, such as the UHF radio used for communications with
spacecraft on the surface of Mars, have worked as long as they were
designed to last.

In addition to its own major scientific discoveries and continuing
studies of the planet, the Odyssey mission has played important roles
in
supporting the missions of the Mars rovers Spirit and Opportunity and
the Phoenix Mars Lander.

JPL, a division of the California Institute of Technology, Pasadena,
manages Mars Odyssey for the NASA Science Mission Directorate,
Washington. Lockheed Martin Space Systems, Denver, is the prime
contractor for the project and built the spacecraft. Additional
information about Odyssey is at http://www.nasa.gov/mission_pages/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

2009-038
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