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

According to the State Administration of Science, Technology and Industry for National Defence (SASTIND), 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 ahead of the lunar night, which also lasts for approximately 14 days during which the temperature falls below minus 180 degrees Celsius.

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 of a lunar goddess in Chinese mythology, touched down on the moon's surface on December 15, some hours after lunar probe Chang'e-3 landed.

The Chang'e-3 probe also entered dormancy early on Sunday morning, after carrying out observations of celestial bodies and the plasmasphere over the Earth, using its optical telescope and extreme ultraviolet camera, SASTIND said.

(Xinhua News Agency February 23, 2014)