Phoenix unexpectedly enters safe mode

PASADENA, Calif., Oct. 30 (UPI) -- The U.S. space agency says its Phoenix Mars Lander has entered safe mode in response to low power levels produced by deteriorating weather conditions.

National Aeronautics and Space Administration engineers said the lander also unexpectedly shut down one of its two batteries.

NASA said that when in safe mode, the Phoenix stops non-critical activities and awaits further instructions from Earth. Within hours of learning of the safe mode event, engineers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., sent commands to restart battery charging.

Officials said they do not believe any stored energy was lost.

Weather conditions at the landing site in the north polar region of Mars have been deteriorating as winter approaches. Overnight low temperatures have been near minus 141F and daytime temperatures only as high as minus 50F -- the lowest temperatures experienced so far in the Phoenix mission.

The lower temperatures caused the lander's battery heaters to turn on Tuesday for the first time, creating another drain on the spacecraft's power supplies.

NASA said science activities will be suspended for several days to allow the spacecraft to recharge and conserve power. Originally scheduled to last 90 days, Phoenix has completed five months of exploration.