Diagnostic wheel tests continue; Investigating 'Marquette' and 'Islington Bay'

This blink comparison aids evaluation of a drive by NASA's Mars Exploration Rover Spirit during the rover's 2,099th Martian day, or sol (Nov. 28, 2009). A stall by the right-rear wheel ended the drive after the first 1.4 meters (4.6 feet) of wheel movement in a two-step drive that had been planned to include a totla of 5 meters (16.4 feet) of wheel movement. As anticipated, nearly all of the wheel movement was slippage. Credit: NASA/JPL-Caltech

Spirit's extrication from her embedded location at Troy on the west side of Home Plate has been complicated by a recurring stall condition with the right rear wheel.

After diagnostic tests on Sol 2095 (Nov. 24, 2009), indicated a freely moving wheel, another two-step drive with 5 meters (16 feet) of wheel spin was commanded on Sol 2099 (Nov. 28, 2009). That drive resulted in another right rear wheel stall after only 1.4 meters (5 feet) of wheel motion.

Analysis of a right rear wheel stall back on Sol 1837 (March 25, 2009), well before embedding, suggests that the stall may not be terrain related, but could be internal to the wheel motor and gearbox. To investigate this, three sets of rotor resistance tests at cold, ambient and warm temperatures were commanded over Sols 2104 (Dec. 3, 2009), and 2105 (Dec. 4, 2009), to check the health of the motor windings and motor brushes. A small right rear wheel motion in the direction of the stall was also commanded on Sol 2104 to see if the stall persists.

The results of these diagnostic tests should be known later tonight (Thursday) and Friday with analyses performed on Friday and over the weekend. The next drive for Spirit would be no sooner than Monday (Dec. 7, 2009).

As of Sol 2099 (Nov. 28, 2009), the rover solar array energy production was 316 watt-hours with an atmospheric opacity (tau) of 0.572 and a dust factor of 0.567. Total odometry is 7,730.00 meters (4.80 miles).

Opportunity has been investigating the rock known as "Marquette Island."

On Sol 2076 (Nov. 25, 2009), the robotic arm (IDD) placed the Mössbauer (MB) spectrometer on a rock target called "Islington Bay" for a long, multi-sol integration.

With the temporary loss of relay operations for a few sols because of the Odyssey spacecraft safe-mode, Opportunity has limited the collection of other science data and continued with the low-data volume MB integrations. The miniature thermal emission spectrometer (Mini-TES) elevation mirror shroud is being opened when appropriate with the expectation of eventual dust cleaning. No dust cleaning of the Mini-TES mirror has been noted yet.

As of Sol 2079 (Nov. 28, 2009), the solar array energy production was 360 watt-hours with an atmospheric opacity (tau) of 0.508 and a dust factor of 0.529. Total odometry was 18,906.82 meters (11.75 miles).