Spirit electronics getting colder; More driving for Opportunity

In her winter position, still embedded in the area called "Troy" on the west side of Home Plate, Spirit has transitioned to executing a single, seven-sol plan each week, as long as power permits.

The seven-sol plan contains a single X-band uplink and a single Ultra-High Frequency (UHF) downlink. The activity on each sol consists simply of a brief wakeup, an atmospheric opacity (tau) measurement, and then a shutdown for the rest of the day and night.

The last downlink from the rover was on Sol 2203 (March 15, 2010). From that downlink, Spirit was still under master sequence control and all systems were green. Energy production was down to 139 watt-hours per sol. Battery state of charge did not decrease significantly, suggesting that Spirit was able to stay roughly power neutral over the last few sols. Solar array energy production levels will continue to drop and rover heating requirements will continue to increase, leading to widening energy deficits.

The solid-state power amplifier (SSPA), as a proxy for the rover electronics module (REM), reached a record low temperature of -41°C (-41.8°F). Spirit is getting colder than ever before. The plan for this week is to sequence another seven-sol plan to be uplinked this Friday with a single UHF downlink over the weekend. Spirit could enter low-power fault at anytime and become quiet for an extended period of time to charge her batteries.

As of Sol 2203 (March 15, 2010), the rover solar array energy production was to 139 watt-hours with an atmospheric opacity (tau) of 0.379 measured on Sol 2202 (March 14, 2010), and a dust factor of 0.507. Total odometry is unchanged at 7,730.50 meters (4.80 miles).

 

Opportunity has been making fast progress along the path to Endeavour crater.

The rover drove four times in the last week totaling almost 285 meters (935 feet) of progress. On Sol 2179 (March 11, 2010), Opportunity, driving backwards to the southwest covered over 70 meters (230 feet) of distance. Next, on Sol 2181 (March 13, 2010), the rover headed more southerly, covering almost 73 meters (240 feet). Then, two more drives due south on Sols 2183 (March 15, 2010), and 2184 (March 16, 2010), achieving 71 meters (233 feet) each. The plan ahead...you guessed it...more driving.

As of Sol 2185 (March 17, 2010), the solar array energy production was 283 watt-hours with an atmospheric opacity (tau) of 0.405 and a dust factor of 0.523. Total odometry is 19,778.24 meters (12.29 miles).

 

Source: Jet Propulsion Laboratory
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