Posted: Thu, Apr 24, 2008, 6:38 AM ET (1038 GMT)
One of the twin Mars Exploration Rovers is suffering from a problem with its robotic arm that could limit its utility, JPL announced Wednesday. A motor that controls the side-to-side motion in the shoulder joint of the arm on the rover Opportunity stalled earlier this month and is currently being studied by engineers. The motor first experienced occasional problems in late 2005, but the latest problem took placed after much less activity than previous problems, suggesting that the problem is worsening. Engineers believe the problem is electrical rather than mechanical in nature, Even if the motor could no longer operate, project officials said the robotic arm could still be used to perform "some contact science" since motors that control other joints in the arm are still working. Opportunity has been on the surface of Mars since January 2004, long exceeding its 90-day lifetime. The rover is currently just inside the rim of Victoria Crater.

Related Links:

•  AP article
•  NASA/JPL press release