Posted: Thu, Feb 5, 2009, 5:23 AM ET (1023 GMT)

NASA's Mars rover Spirit has resumed driving after being sidelines for several days by a mysterious glitch. The rover moved about 30 centimeters Saturday, the first movement by Spirit since the spacecraft suffered a glitch a week earlier that prevented it from storing data and orienting itself properly. While ground controllers were able to get the spacecraft properly oriented again, they have determined what caused the problems to begin in the first place. Project managers speculate that a cosmic ray hit may have caused the rover to turn off its flash memory. Spirit, designed to operate for only 90 days, has now been on the Red Planet for over 1,800 Martian days.