[Tyler]

NASA Adds 2nd Test Rover to Help Free Spirit
     


According to the Free
Spirit blog, NASA has added a second test rover to the project,
where scientists are working on a way of freeing the stuck Mars Rover,
Spirit. The rover is stuck in soft soil at a site called Troy. The
researchers are trying to duplicate the conditions in a lab to help
develop strategies that would get the rover unstuck. But simulating Mars
on Earth isn't easy as JPL's John Callas explains:
There is no perfect Earth analog for Spirit's current
situation. There's less gravity on Mars, little atmosphere, and no
moisture in the soil where Spirit is. It is not anything like being
stuck in sand or snow or mud on Earth. Plus, since the rover moves only
about as fast as a tortoise, you cannot use momentum to help. No rocking
back and forth as you might do on Earth."

To complicate matters there is a large pointy rock beneath Spirit. Any
escape path has avoid putting the rover's center of gravity directly
over the rock. Otherwise, Spirit might get free of the sand only to become
stuck on the rock. For more, see our June update on Spirit's astronomy photos
and panoramas of the area where it's stuck.
   

http://robots.net/article/2905.html