Mars rover encounters technical problems

PASADENA, Calif., Jan. 29 (UPI) -- U.S. space agency scientists said the Mars rover called Spirit has exhibited technical problems, including failing to report some of its weekend activities.

The National Aeronautics and Space Administration scientists said they plan to run diagnostic tests to determine why Spirit didn't report as scheduled, including failing to determine its orientation after an incomplete drive.

"On Sunday, during the 1,800th Martian day, or sol, of what was initially planned as a 90-sol mission on Mars, information radioed from Spirit indicated the rover had received its driving commands for the day but had not moved," NASA said. However, scientists said other behavior was even more unusual: Spirit apparently did not record the day's main activities into non-volatile memory -- the part of its memory that persists even when power is off.

On Tuesday, Spirit's controllers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., commanded the rover to find the sun with its camera in order to precisely determine its orientation. Not knowing its orientation could have been one possible explanation for Spirit not doing its weekend drive, NASA said. Spirit reported that it had followed the commands, and in fact had located the sun, but not in its expected location.

"We don't have a good explanation yet for the way Spirit has been acting for the past few days," said JPL's Sharon Laubach. "Our next steps will be diagnostic activities."