Posted by jburk to Mars Exploration Rovers at October 22, 2004 01:14 PM

Not only are NASA's seemingly unstoppable Mars rovers continuing their progress half a year beyond their design lifetimes, but Opportunity has recently shown an unexplained increase in its solar-cell power output, NASA has revealed. Spirit is faring less well, however, with intermittent wheel problems. Opportunity’s 1.3 metres of solar cells provided about 900 watt-hours per day when the mission began in January 2004, but that level had dropped to between 500 and 600 by June as dust slowly accumulated on the horizontal panels and as winter advanced.