Monday, August 18, 2008

China's first lunar probe satellite normal after eclipse

China's solar-powered lunar probe satellite Chang'e 1 stood the test of a partial eclipse on Sunday as scientists altered its orbit and temporarily turning off some facilities.

Based on the signals sent by the satellite after the eclipse, the Chang'e 1 was operating as expected, Monday's Beijing News quoted Liu Junze, of the Beijing Aerospace Control Center , as saying.

The ground control center changed the orbit of the satellite to shorten the time it was out of direct sunlight to 168 minutes, according to the scientist.

The satellite, if its orbit was unaltered, would have been out of the sun's rays for 220 minutes, he said, adding the time had exceeded the satellite's maximum power reserve.

The center also switched off some facilities at about 3:21 a.m. on Sunday to save power, and temporarily lost contact with the satellite for more than three hours, he noted.

Sunday's eclipse occurred between 3:35 a.m. and 6:44 a.m., and the satellite was hidden from the solar rays about the same period. The moon's shadow, also a signal blind area, could cause a power shortage in freezing temperatures.

During the first eclipse on Feb. 21, scientists adopted the same practice including changing the satellite orbit and switching off some equipment when it was out of direct sunlight.

The satellite successfully ran on battery power for two hours in February.

The 2,350-kilogram satellite, which has been in orbit for nine months, carries eight surveying facilities to make a three-dimensional survey of the moon's surface.

The launch of the lunar probe is the first step in China's three-stage moon mission, which will lead to a landing and launch of a rover vehicle around 2012. In the third phase, another rover will land and return to the Earth with lunar soil and stone samples for scientific research around 2017.


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