Mars rover’s broken wheel is beyond repair The New Scientist

Mission managers have given up hope of fixing a broken wheel on NASA’s Spirit rover and will simply have to drag the wheel on future drives. The glitch means NASA must avoid terrain with loose soil as it maps out a route to a safe winter haven for the rover.
The rover’s right-front wheel stopped turning about two weeks ago – apparently because of a broken circuit in the motor that powers the wheel. The same wheel had experienced a surge in current in 2004 but later returned to normal.