Posted: Sun, May 30, 2004, 9:29 AM ET (1329 GMT)
The Mars Exploration Rover Opportunity has successfully used a "deep sleep" mode designed to deal with a long-running power drain on the spacecraft. Spacecraft controllers performed a more complete shutdown of the rover overnight, allowing them to turn off a heater element that has been running continuously throughout the mission because of a faulty switch. The heater had been draining power from the spacecraft, limiting it to just a few hours a day of operations. The deep sleep operation was successful, with no damage to the rover or sensitive instruments after being exposed to cold overnight temperatures. There were concerns that one instrument, the Mini-TES spectrometer, could be damaged by exposure to the cold. The new operation mode should allow Opportunity to continue operations for several more months. Spirit, the twin to Opportunity, doesn't require a deep sleep mode because it does not have faulty heaters.

Related Links:

•  AP article
•  NASA/JPL mission status report