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

Mars Pathfinder Mission Status
October 1, 1997

After experiencing difficulties in communicating with the Mars Pathfinder spacecraft for the past three days, the operations team was able to reestablish a brief two-way communications session Tuesday using the lander's auxiliary transmitter. Receipt of this beacon signal indicated that the spacecraft is still operational.

The team began having communications problems with the spacecraft on Saturday, Sept. 27. These problems could be related to degradation of the spacecraft's battery. The last successful data transmission cycle from Pathfinder was completed at 3:23 a.m. Pacific Daylight Time on Sept. 27, which was Sol 83 of the mission.

No signal was received from the spacecraft on the next Martian day, Sol 84, which began in the evening of Sept. 27. The team's transmission session began at 11:15 p.m. PDT. The lack of a signal, at that time, was thought to be caused by a possible computer reset incident, ground system problem or low voltage condition. A reset or a low voltage condition, caused by the aging of the battery, would cause the spacecraft sequence to automatically stop and not execute its planned communication with Earth.

The team attempted to communicate with the spacecraft again
on Sept. 29 (Sol 85) and Sept. 30 (Sol 86) with no success.

Tonight, on Sol 88 of the mission, the team will use the auxiliary transmitter again to attempt to acquire engineering data that will help them assess the cause of the communications problem. Meanwhile, the rover, which receives its instructions from Earth via the lander, is currently running a contingency program which has instructed it to stand still rather than begin its trek around the lander.

The team will repeat these activities on subsequent days and attempt to receive telemetry that will give them more information about the health of the lander and rover.

If Pathfinder operations do not return to normal tonight, a Mars Pathfinder team representative will provide an update on the situation at the beginning of the planned Mars Global Surveyor science news briefing at 9 a.m. PDT on Thursday, Oct. 2.

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