Flight Team to Check Status of Backup System

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif. March 4, 2009
guy.webster@jpl.nasa.gov

Flight Team to Check Status of Backup System

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 .

#2009-038
-end-

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=cdJMKONjEfKQK2L&s=lvK4LaNRIhLQI9PXIvF&m=fiIOK2OEJiK5G

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=fqLSKXOvGiJXIcK&s=lvK4LaNRIhLQI9PXIvF&m=fiIOK2OEJiK5G