Posted by jburk to Mars Exploration Rovers at August 26, 2004 12:43 PM

On a recent day some of them were behind a laboratory at a pile of sand that resembles the surface of Mars. They were trying to drive a rover, like the two currently on Mars. The JPL scientists were trying to operate one with the kind of mechanical defect — an inoperative drive wheel — that is giving a slight limp to one of the rovers operating on the red planet 110 million miles away.