coondoggie writes "NASA says it is narrowing a short list of things its scientists can do to extricate its stuck Mars Spirit rover. They are exploring a couple remaining options, such as driving backwards and using Spirit's robotic arm to sculpt the ground directly in front of the left-front wheel, the only working wheel the arm can reach. The amount of energy that Spirit harvests each day, however, is declining, as autumn days shorten on southern Mars. 'At the current rate of dust accumulation, solar arrays at zero tilt would provide barely enough energy to run the survival heaters through the Mars winter solstice.' NASA is currently analyzing results of a Jan. 13th attempt to move the spacecraft that involved a very slow rotation of the wheels. Earlier drives in the past two weeks using wheel wiggles and slow wheel rotation produced negligible progress toward extricating Spirit, NASA stated."