The Chang'e-1 lunar probe yesterday successfully
completed its third orbital transfer, taking it one step closer to
completing its 1.58-million-km journey to the moon.
Officials from the Beijing Aerospace Control Center (BAAC) said
the probe successfully transferred to a 48-hour orbit at about 6:01
pm. It will stay on that path until tomorrow, after which it is
expected to enter an Earth-moon transfer orbit, a critical point
that might determine whether or not the satellite reaches its final
destination.
Now at a distance of more than 120,000 km from Earth, Chang'e-1
has set a new record in China's aerospace history as the most
distant satellite ever controlled by Chinese scientists. The
previous record stood at 80,000 km.
Wang Yejun, chief engineer with the BACC, said ultraviolet image
sensors installed on the satellite will soon begin to collect
information on the Earth and moon once it enters the 48-hour
orbit.
The images will not be transmitted back to Earth, however, until
Chang'e-1 enters the lunar orbit, he said.
The China National Space Administration said on its website
yesterday that land- and sea-based surveillance posts, as well as
four astronomical observatories, have kept watch over the
satellite's progress since Saturday.
"According to the data received so far, all systems have been
working normally," it said.
In the following 10 days, Chang'e I is scheduled to carry out
three critical moves, the administration said.
Tomorrow, it will enter the Earth-moon transfer orbit. During
this time, any mistakes made will result in the failure of the
mission, the administration said.
On November 5, Chang'e-1 will attempt to enter a lunar orbit, at
which time it will run the risk of either crashing into the moon or
flying straight past it.
Finally, on November 7, the satellite will attempt to move into
a much tighter orbit, circling just 200 km above the moon's
surface.
Yang Duohe, chief engineer at the lunar probe program center,
said Chang'e-1 will send back data collected during this section of
its flight on December 18. If that is successful, all detectors
fitted to the satellite will be turned on to enable a full
scientific probe, he said.
As of 7?pm on Sunday, Chang'e-1 had circled the Earth five
times in 96 hours, the space administration said.
Ji Gang, a designer with the lunar program, said by the time the
satellite reaches it final orbiting position, it will have traveled
a total of 1,585,219 km. It has so far journeyed 500,000 km.
(China Daily October 30, 2007)