The Spirit is willing, but the wheels are weak

The Spirit rover continues to be stuck up to its hubcaps on Mars, but JPL engineers have put together a simulation of the conditions Spirit has encountered and are busy attempting various scenarios to drive the plucky rover free of its sand trap. The same technique got sister rover Opportunity out of a similar jam back in 2005, so JPL are hopeful they can work the same magic again. A fully operating twin of Spirit is now in a box of sand in Pasadena and Wired magazine have an excellent article online detailing the preparations to build the simulation.