NASA works to free Mars rover Spirit

PASADENA, Calif., May 19 (UPI) -- The U.S. space agency says it's considering the best maneuvers for freeing the Mars rover Spirit, which has become immobilized in soft martian soil.

The National Aeronautics and Space Administration said a diagnostic test conducted Saturday provided favorable indications about Spirit's left middle wheel. NASA engineers said the weekend test showed electrical resistance in the left middle wheel is within the expected range for a motor that has not failed.

"This is not a full exoneration of the wheel, but it is encouraging," said John Callas of NASA's Jet Propulsion Laboratory, project manager for Spirit and its twin rover, Opportunity. "We're taking incremental steps. Next, we'll command that wheel to rotate a degree or two. The other wheels will be kept motionless, so this is not expected to alter the position of the vehicle."

NASA said its Mars Odyssey orbiter is also aiding in the Spirit recovery plan by receiving extra transmissions from Spirit. The transmissions include imaging data from Spirit's examinations of soil properties and ground geometry.

NASA said it's using that data and other information to construct a simulation of Spirit's situation in a rover testing facility at JPL.

Weeks of testing are anticipated before any attempt to move Spirit, officials said.