NASA fails again in attempt to free Spirit

PASADENA, Calif., Dec. 2 (UPI) -- NASA is again reporting failure in the latest of its attempts to free the stuck Mars rover Spirit from a sand trap on the surface of the Red Planet.

Scientists at the space agency's Jet Propulsion Laboratory said Spirit's right-rear wheel stalled Nov. 28 during the first step of a two-step extrication maneuver. But officials said the stall is different in some characteristics from a Nov. 21 stall. NASA said the most recent event occurred more quickly and the inferred rotor resistance was elevated at the end of the stall.

Investigation of past stall events, along with the new characteristics, suggest the latest stall might not be result of the terrain, but might be internal to the right-rear wheel actuator, NASA said.

"Rover project engineers are developing a series of diagnostics to explore the actuator health and to isolate potential terrain interactions," the space agency said, noting plans for future driving will depend on the results of the diagnostic tests.

The space agency said earlier its attempt to extract Spirit from the martian sand trap is expected to take weeks or even months, with uncertain probability of success.

Spirit has been stuck in loose martian sand since April 23.