The computer on Spirit started crashing on Wednesday, and the problem has been traced to part of the computer memory, said Mr. Theisinger, the project manager. It will still take some time for the problem to be fully diagnosed and for the engineers to devise procedures to work around it. "I think we're probably like three weeks away from driving," Mr. Theisinger said. The troubles began Wednesday, as controllers were testing one of the instruments. Spirit's computer crashed, and over the next two days, a cycle of rebooting and crashing repeated more than 60 times. The rover also did not shut down at night. Suspecting that the problem might be with the flash memory, flight controllers radioed instructions for Spirit to start up in what Mr. Theisinger called the cripple mode, using only the RAM and not the flash memory. For the first time since Wednesday, the rover's software did not crash. This is the first clear explanation I've read of the problems with Spirit. Restoring a Red Rover's Spirit | 
