The National Aeronautics and Space Administration said its rover team decided to select a new exploration route since the rover has the use of only five of its six wheels. The right-front wheel stopped working in 2006, so it usually drives backward, dragging that wheel. It can no longer climb steep slopes, NASA said.
"After several attempts to drive up-slope in loose material to get around the northeast corner of Home Plate, the team judged that route to be impassable," said John Callas of NASA's Jet Propulsion Laboratory in Pasadena, Calif., the project manager for the twin Mars rovers.
The new route to get toward science targets south of Home Plate is to go around the west side of the plateau.
"The western route is by no means a slam dunk," said Steve Squyres of Cornell University, the principal investigator for the rovers' science instruments. "There are no rover tracks on that side of Home Plate like there are on the eastern side. But that also makes it an appealing place to explore. Every time we've gone someplace new with Spirit since we got into the hills, we've found surprises."