Chang'e I will experience a lunar eclipse around February 21.
This may lead to a power shortage because of the lack of sunlight
on its solar panels that generate electricity, experts have
said.
The lunar eclipse will be the first of two that are expected,
with the second likely to occur in August, Ye Peijian, lead
designer of Chang'e I, said.
"The orbiter will be operating without a solar power supply for
five-and-a-half hours," he said yesterday in an online
interview.
The temperature on the lunar orbiter will subsequently drop to
nearly minus 130 C.
"The eclipses will be a real challenge for the proper function
of various pieces of equipment on Chang'e I," he said.
Rao Wei, a designer at the Academy for Space Technology
Research, said repeated testing and preparation beforehand should
be able to solve the "blackout" problem.
The storage battery will be put to use during the blackout to
power the normal operation of the lunar probe, he said.
Non-essential equipment on the orbiter is also designed to
pause, allowing the limited power of the battery to work key parts
during the blackout, Rao told the Xinhua News Agency.
Enhancing the performance of the storage battery and
cold-resistant devices on the satellite will keep warming the
probe, he said. In normal conditions the solar battery is recharged
every 127 minutes.
Eclipses occur when the Earth is positioned on a straight line
with the Sun and the moon. In a lunar eclipse, the Earth's shadow
falls on the moon, darkening it, and can be seen from wherever on
Earth the moon is above the horizon.
(China Daily November 30, 2007)