Mars and Earth Activities Aim to Get Spirit Rolling Again
NASA's rover project team is using Spirit and other spacecraft at Mars to find a way for the rover to get dislodged from soft Martian ground.
Mars Exploration Rover Mission Status ReportPASADENA, Calif. -- NASA's rover project team is using the Spirit 
rover and other spacecraft at Mars to begin developing the best 
maneuvers for extracting Spirit from the soft Martian ground 
where it has become embedded.A diagnostic test on May 16 provided favorable indications about 
Spirit's left middle wheel. The possibility of the wheel being jammed 
was one factor in the rover team's May 7 decision to temporarily suspend 
driving Spirit after that wheel stalled and other wheels had dug 
themselves about hub-deep into the soil. The test over the weekend 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, Pasadena, Calif., 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."Another reason to suspend driving is the possibility that the wheels' digging 
into the soil may have lowered the body of the rover enough for its belly pan to 
be in contact with a small mound of rocks. The rover team is using Opportunity 
to test a procedure for possible use by Spirit: looking underneath the rover with 
the microscopic imager camera that is mounted on the end of the rover's arm. This 
might be a way to see whether Spirit is, in fact, touching the rocks beneath it.NASA's Mars Odyssey orbiter is also aiding in the Spirit recovery plan.  As a result 
of winds blowing dust off Spirit's solar panel four times in the past month, Spirit 
now has enough power to add an extra communication session each day. The Odyssey project 
has made the orbiter available for receiving extra transmissions from Spirit. The 
transmissions include imaging data from Spirit's examinations of soil properties 
and ground geometry.Rover team members are using that data and other information to construct a 
simulation of Spirit's situation in a rover testing facility at JPL. The team is 
testing different materials to use as soil that will mimic the physical properties 
of the Martian soil where Spirit is embedded. Later, the team will test maneuvers 
to get the rover free. Weeks of testing are anticipated before any attempt to move Spirit.JPL, a division of the California Institute of Technology in Pasadena, manages the 
Mars Exploration Rover project for NASA’s Science Mission Directorate, Washington.