Spirit is recovering from the high-gain antenna (HGA) anomaly that occurred on Sol 2027 (Sept. 15, 2009). The HGA problem is suspected to be an apparent intermittent behavior in the dynamic brake relay for the HGA actuators, a problem that has been seen and mitigated before in other rover actuators.
Diagnostics were run on the HGA and each actuator moved freely in both directions without problems with the dynamic brake behaving normally.
The challenge for the rover team has been trying to uplink HGA recovery sequences over the low-gain antenna (LGA). Data rates over the LGA are so low that there is often insufficient time in the uplink window to get up all the necessary commands.
Because of that, the project is using forward link UHF relay commanding through Mars Odyssey. The forward link has the additional complication that there is additional latency in getting the commands to the rover, so the pace of recovery is impacted.
Return to normal HGA usage for Spirit is anticipated by next week. Spirit is otherwise in good health.
As of Sol 2033 (Sept. 21, 2009), Spirit's solar-array energy production was 418 watt-hours with an atmospheric opacity (tau) of 0.972 and a dust factor of 0.626. Total odometry remains at 7,729.93 meters (4.80 miles).
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