Uneasy rest begins for China's troubled Yutu rover

This undated photo taken by the camera on the Yutu moon rover shows the Chang'e-3 moon lander and the moon surface. The Chang'e-3 lander entered its third dormancy on early Feb 23, 2014. (Xinhua/SASTIND)

China's lunar rover Yutu entered its third planned dormancy on Saturday, with the mechanical control issues that might cripple the vehicle still unresolved.[Special coverage]

According to the State Administration of Science, Technology and Industry for National Defence (SASTIND) on Sunday, Yutu only carried out fixed point observations during its third lunar day, equivalent to about two weeks on Earth.

Yutu's radar, panorama camera and infrared imaging equipment are functioning normally, but the control issues that have troubled the rover since January persist.

The rover went to sleep mode on Saturday afternoon.

During the lunar night, there is no sunlight to power Yutu's solar panels. In this period, the rover is expected to stay in a power-off mode and communication with Earth is cut.

Yutu, named after the pet rabbit of the lunar goddess Chang'e in Chinese mythology, touched down on the moon's surface on Dec 15, some hours after lunar probe Chang'e-3 landed.

The rover was designed to roam the lunar surface for at least three months to survey the moon's geological structure and surface substances and look for natural resources.

But problems emerged before the rover entered its second dormancy on the moon on Jan 25 as the lunar night fell. According to SASTIND, the mechanic control abnormality occurred due to the "complicated lunar surface."

Experts had feared that it might never function again, but Yutu "woke up" on Feb 12, two days behind schedule, and caused a stir in China's social networking circles.

[Related: Lunar rover 'awakes' despite abnormality: spokesman]

A the awakening was announced by an unverified user named "Jade Rabbit Lunar Rover", which posts first-person accounts in the "voice" of the probe, and has gone viral on Weibo.com.

"Hi, anybody there?" it asked, prompting over 60,000 reposts and 40,000 comments within two hours.

[Related: Young Beijing woman the 'voice' of Yutu]

Its latest post on Sunday, which featured a picture of the Chang'e-3 probe taken by Yutu during its third lunar day and the caption of "zzz", implicating the lunar rover had gone asleep, were also reposted by thousands within minutes.

"Remember to wake up on time, you lazy bones," one wrote in reply.

Meanwhile, the Chang'e-3 lunar probe, which carried Yutu to the moon's surface, also entered dormancy in the wee hours of Sunday morning, after carrying out observations of celestial bodies and the Earth's plasmasphere using its optical telescope and extreme ultraviolet camera.

China is the third country to soft-land on the moon after the United States and the Soviet Union.

Chang'e-3 is part of the second phase of China's lunar program, which includes orbiting, landing and returning to Earth. The country has also sent probes to orbit the moon in 2007 and 2010, the first of which crashed onto the lunar surface at the end of its mission.

The second probe was sent to verify key technologies for Chang'e-3 and reconnoitered the landing area, before being sent into deep space.

According to the SASTIND, the Chang'e-2 has become China's first man-made asteroid, and is currently 70 million kilometers from the Earth.