Mars Pathfinder Mission Status - 7 February 1997


From: Jan Wee <jwee@mail.arc.nasa.gov>
Subject: Mars Pathfinder Mission Status - 7 February 1997
Date: Sat, 08 Feb 1997 09:24:01 -0600


Dear discuss-lfm members,

FYI -- the latest "scoop" on the Pathfinder Mission....

MARS PATHFINDER MISSION STATUS REPORT
7 February 1997

Successfully completed Trajectory Correction Maneuver #2 on February 3. The
purpose of this maneuver was to clean up TCM-1 execution errors and had a
magnitude of about 1.6 m/s. The maneuver consisted of two parts, an axial
component of 1.5 m/s and a lateral component of 0.1 m/s. All spacecraft
subsystems performed as expected, and the resulting maneuver execution error was
less than 2%. The spacecraft was turned back to Earth after the maneuver, and
will remain in this attitude until late March.

The spacecraft computer reset during an off-track period on Wednesday, February
5. Analysis of post reset telemetry indicates that it was caused by a divide-by-
zero fault in the attitude control flight software (ACS). The spacecraft
responded as expected to this anomaly, and correctly enforced the early cruise
boot configuration. This configuration idles ACS and reduces the uplink and
downlink data rates from nominal cruise values. Several commands were sent on
February 6 to increase the data rates and return diagnostic data, but attitude
control is still idle. The spacecraft is in a safe attitude, however, so there
is no compelling reason to restart ACS.

An all-hands science team meeting was held on February 5-7. All existing
investigators plus the newly selected ASI/MET FIST scientists and participating
scientists were invited. The purpose of this meeting was to organize the science
teams into a set of science operations groups and to review the current baseline
plans for surface operations. A number of useful suggestions were made for
modifying the nominal Sol 1-2 plans.

For further information on the Mars Pathfinder Mission, please visit our website
at http://mpfwww.jpl.nasa.gov.