Opportunity is still positioned at the target called "Chester Lake" at Cape York on the rim of Endeavour crater. The rover continues with the in-situ (contact) science investigation of the surface rock called "Salisbury 1."

On Sol 2726 (Sept. 24, 2011), the previously ground Rock Abrasion Tool (RAT) hole was re-brushed to remove excessive tailings. Microscopic Imager (MI) images were collected confirming the successful brushing. The Alpha Particle X-ray Spectrometer (APXS) was placed down on the target for a post-brush integration.

On Sol 2729 (Sept. 27, 2011), the APXS was retracted from the RAT hole, a Pancam 13-filter image set was taken. Then, along with more MI images, a test of the MI poker was performed.

The test results indicate normal operation of the poker. The Moessbauer (MB) spectrometer was placed down in the hole for a multi-sol integration.

As of Sol 2729 (Sept. 27, 2011), solar array energy production was 313 watt-hours with an atmospheric opacity (Tau) of 0.882 and a solar array dust factor of 0.514.

Total odometry is 20.86 miles (33,574.75 meters, or 33.58 kilometers).