Opportunity brushing out the RAT cuttings; Toe-in maneuver before drive for Spirit

Opportunity has been investigating the rock known as "Marquette Island." The rock abrasion tool (RAT) was used to grind a 1.5-millimeter-deep (0.06-inch-deep) hole in this very hard rock at the target called "Peck Bay 2."

The alpha particle X-ray spectrometer (APXS) measurements of Peck Bay 2 were significantly different than the pre-grind measurements. Based on these results, Opportunity is spending another week at Marquette Island for more observations of Peck Bay 2.

Opportunity completed a RAT brush of the hole, clearing out the cuttings left by the grind. Microscopic imager (MI) mosaics confirmed the success this activity. Opportunity is continuing to complete APXS measurements of Peck Bay 2 at different positions.

The elevation mirror shroud of the miniature thermal emission spectrometer (Mini-TES) 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 2117 (Jan. 6, 2010), Opportunity's solar-array energy production is 320 watt-hours, with an atmospheric opacity (tau) of 0.438 and a dust factor of 0.519. Total odometry is 18,927.56 meters (11.76 miles).

 

Spirit remains embedded at the location called "Troy" on the west side of Home Plate. Attempts to extricate Spirit have been complicated by the lack of functionality in both the right-rear and right-front wheels.

On Sol 2132 (Jan. 1, 2010), the left-front, left-rear, and right-rear wheels were steered 60 degrees toe-in to try and cause material in front of the wheels to collapse into the trenches in which the wheels are embedded. The wheels were then steered back to straight forward in an attempt to use the flat outer surface of the wheel to push the previously collapsed material to the side of the wheel. The intent of this is to provide a free space in front of each wheel into which it may move. Four 2.5-meter (8.2-foot) forward drive steps were then commanded. The right-front wheel was then steered inward 60 degrees to allow driving with the wheel threads more aligned with the direction of motion. The Sol 2132 drive was terminated during the initial steering of the wheels due to the flight software believing the left-rear steering motor had stalled. The left-rear wheel was continuing to steer but resistance from the surrounding soil had slowed it to a rate that the flight software did not detect as motion.

For Sol 2136 (Jan. 5, 2010), the team sequenced a drive to continue where the Sol 2132 drive terminated. The left-front, left-rear, and right-rear wheels were commanded back to straight. Four 2.5-meter (8.2-foot) drive steps were then commanded. The right-front wheel was then commanded to steer inward 60 degrees. An additional four 2.5-meter (8.2-foot) drive steps were commanded. The drive was terminated due to the onboard sinkage measurement in excess of 1 centimeter (0.4 inch). This drive achieved only 2.28 centimeters (0.9 inch) of forward progress.

As of Sol 2136 (Jan. 5, 2010), Spirit's solar-array energy production is 243 watt-hours, with an atmospheric opacity (tau) of 0.482 and a dust factor of 0.545. Total odometry is 7,730.08 meters (4.80 miles).

 

Source: Jet Propulsion Laboratory
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