The Mars rover team is using a test rover at JPL to assess various extraction techniques that might get Spirit out of the loose soil of "Troy" on Mars.
One of the maneuvers being run with the test rover involves turning the rear wheels toward the left while the left-front wheel is turned toward the right, and driving forward to pivot around the inoperable right-front wheel.
Engineers and scientists on the rover team are evaluating several repeats of this forward-right-arc maneuver in the sandbox at JPL as part of a weeks-long series of tests to identify maneuvers that might help Spirit.
Meanwhile Spirit is using abundant power from its solar panels, recently cleaned by Martian winds, to examine the composition of soil layers at Troy and make daytime and nighttime observations.
See also: Rover Tests Evaluating Crabwalk Moves at www.physorg.com/news166727314.html
Provided by JPL/NASA (news : web)
Explore further: Spirit rover's wheels stuck in soft Martian dirt