Mars rover may be stuck, but still doing science

Spirit’s wheel dug into layers of soil at Troy location, exposing stuff to studyThe Mars rover Spirit is keeping scientists' spirits up by doing some science while it is stuck in soft soil on the Red Planet. The rover has been immobile, trapped hub-deep since May 6. Engineers have replicated the landscape in a lab back home and, using an identical rover model, tried to figure out what to do, so