Narrow windows for China's lunar probe launch

XICHANG - The launch of China's Chang'e-3 lunar probe, scheduled in early December, will have to target multiple narrow windows that last only minutes each, said a spokesman for the project Friday.

"The lunar probe currently has two launch windows each day for three consecutive days. The first window on the first day lasts four minutes, and the second window one minute," said Pei Zhaoyu, spokesman for the lunar probe mission, at a press briefing in Xichang, Sichuan province.

According to Pei, Chang'e-1 and Chang'e-2, which were both successful in completing their lunar probe missions, had each only one window that lasted 35 minutes.

A scientist with the State Administration of Science, Technology and Industry for National Defence said previously that different trajectory parameters have to be adopted quickly as intervals between the windows are very short.

"China has researched and built a series of special experiment facilities and adopted various advanced testing methods in order to ensure the success of the mission," Pei said, citing simulations of the low-gravity environment and complicated terrain on the moon.

Pei revealed that Chang'e-3 will use advanced radars to observe the lunar crust structure at shallow depths along its scouting path while detecting elements of the moon with spectral technology.

During the mission, a moon-based optical telescope will also be used for astronomical observation, according to the spokesman.

The Chang'e-3 mission is the second phase of China's lunar program, which includes orbiting, landing and returning to Earth. It follows the success of the Chang'e-1 and Chang'e-2 missions in 2007 and 2010.

Chang'e-3 will land on the moon in mid-December if all goes well.