NASA's second Mars exploration rover, Opportunity, was expected to roll off its lander as early as 1 February after a successful touchdown in Meridiani Planum on 25 January. On the other side of Mars, meanwhile, the Spirit rover should resume operation this week.

Opportunity stood up on its landing platform and untucked its front wheels on 28 January, after coming to rest in a 20m (65ft)-wide crater. Once it leaves the lander, the rover will head for an outcrop of bedrock on the inside slope of the shallow crater. Geologists believe the layered rock possibly originated either from sediments carried by water or wind or falling volcanic ash. The dark-colour soil, meanwhile, may contain the mineral hematite, which usually forms in the presence of water, says NASA.

The rover is losing some of its battery charge each night due to an electric heater on the shoulder joint of its robotic arm. Ground control has been unable to activate a switch designed to overrule the heater's thermostatic control when the arm is not in use. The power drain does not impose any short-term operational constraints, says NASA.

Spirit, meanwhile, began using its high-gain antenna again on 28 January, speeding efforts to regain complete control of the vehicle. After finding a way to stop the rover's computer rebooting itself about once an hour, engineers began erasing unneeded files from Spirit's flash memory to resolve a problem that had interrupted data communications on 21 January.

The first picture returned since Spirit fell silent shows the rover still poised before a rock dubbed Adirondack, ready to begin close-up examination using its robotic arm once full control is restored.

Source: Flight International