Lunar rover is 'awake' but faults continue

China's first lunar rover, Yutu, or Jade Rabbit, is still "alive" despite the malfunction of some of its equipment, according to a senior space scientist.

"Yutu has been woken up after the past dormancy, but the problems still exist," Wu Weiren, chief designer of China's lunar probe project, told Xinhua News Agency in Hong Kong.

Wu was to attend an exhibition set to open on Monday in Hong Kong that features the achievements China has made in its lunar exploration project.

He said the rover will embrace its eighth "working day", which is about 14 Earth days, in an abnormal state caused by mechanical failures, noting that "fortunately, the rover has completed its designated scientific and engineering tasks".

During the lunar night, there is no sunlight to provide power to Yutu's solar panel, and the extremely low temperatures would damage its delicate electronics, so the rover must "hibernate".

The 140-kilogram, six-wheeled Yutu, part of the Chang'e-3 lunar probe, has outlived its designed lifespan of three months since it reached the moon in mid-December. Using its scientific apparatus, the rover has analyzed major elements on the lunar surface and studied mineral resources.

However, after nearly six weeks of operation, the moon buggy reported a mechanical control problem on Jan 25 before entering its second dormancy.

Since then, it has been unable to move any farther, remaining about 20 meters southwest of where it landed. The antenna and solar panels cannot be folded, either.

Chinese engineers blamed the problem on the "complicated lunar surface environment".

Zhang Yuhua, deputy head of Yutu's design team, said experts have concluded that the rover was probably damaged by large rocks when it was moving. She said the landing site's environment was even worse than scientists had expected.

It has become virtually impossible to resolve the mechanical failures, given that many parts on Yutu have approached the end of their designed lifespan, Zhang said.

The Chang'e-3 probe, which landed on the moon on Dec 14, is part of the second phase of China's current lunar program that includes orbiting, landing and returning to Earth. It follows the success of the Chang'e-1 mission in 2007 and Chang'e-2 mission in 2010.

Chinese scientists and engineers are now focusing on the third step of the program, namely landing on the moon and returning to Earth with samples extracted from the surface, Wu said.

The mission will be conducted by the Chang'e-5 probe around 2020, he said, adding that Chang'e-5 will be transported by the nation's first heavy-lift rocket, the Long March-5, in the new launch center at Wenchang on the island province of Hainan.

Development of the Long March-5 and the construction of the Wenchang launch center are faring well, according to Liu Jianzhong, deputy designer of the lunar program's rocket system.

Contact the writer at zhaolei@chinadaily.com.cn