Following problems with its A-Side computer (symptoms of a corrupted memory location were being shown) on 28 February 2013 the NASA Mars Curiosity Rover was switched to the redundant onboard computer on the B-side computer. This swap caused the rover to fall into a safe mode. Curiosity exited safe mode and resumed using its high-gain antenna on 2 March 2013.
Composite image of Mars Rover on surface of Mars. Courtesy: NASA/JPL