spacetoday.net: Mars rover suffers arm problem

Posted: Tue, Dec 6, 2005, 7:39 AM ET (1239 GMT)
Mars Exploration Rover (NASA/JPL)

One of the twin Mars Exploration Rovers that have been exploring the surface of Mars for nearly two years is currently unable to move its experiment arm, a problem that could significantly limit the amount of science it can do. Project officials said Monday that the robot arm on the Opportunity rover stopped moving about ten days ago because of a problem in the arm's shoulder joint. Engineers don't know why the joint isn't moving, although it does not appear to be blocked by anything. An "A team" of engineers is working on the issue to either fix the joint or at least allow the joint to move once more, putting the arm out in an extended position that would allow scientists to use the instruments mounted on the end of the arm. The arm on Opportunity's twin, Spirit, has not suffered any problems other than a rock abrasion tool on its tip that has worn down. The rovers were designed to operate for 90 days on the surface, but have now been working since January 2004.