Troubles plaguing China's Yutu (Jade Rabbit) moon rover are yet another reminder to mankind of how difficult lunar exploration is. In 2016, Russia is planning to launch Luna-25, a cutting-edge lunar lander consisting of five modules.

Moon-bound spacecraft must be designed, built and equipped so as to meet tricky lunar realities.

The "mechanical control abnormalities" experienced by Jade Rabbit owe to a "complicated lunar surface environment", the Chinese media reported. Bloggers were more precise: solar panels failed to fold back properly as the rover was preparing to shut down for its second lunar dormancy period.

Tiny particles of rock that got into the mechanism or a computer fault, anything could be to blame. Pang Zhihao of the China Academy for Space Technology (CAST) attributed the problem to high radiation levels, low gravity and sharp temperature fluctuations on the Moon.

Dozens of Soviet and US spacecraft have landed on the Moon since the 1960s. So by now, its properties are well known to space designers: vacuum, very low temperatures (up to minus 180 degrees Celsius), radiation and loose rock.

Luna-25 will also "sleep" during lunar nights, each being 14 Earth days long, Igor Mitrofanov, head of the gamma spectroscopy laboratory at the Russian Institute of Space Research, told the Voice of Russia.

"It would be more effective if an apparatus uses all the energy it generates to keep itself warm. Our apparatus will be wrapped in a special blanket of multilayer film and will retain minimum operating capacity throughout the dormancy period.

"A radiation-resistant elementary base must be applied in order to minimize radiation-related damage. Systems should be duplicated to protect the main parts of the apparatus, its logically active parts, from the harmful effects of cosmic rays," he said.

Soviet lunar rovers also periodically "fell asleep". Scientists soon became aware of a treacherous nature of lunar dust. Electrified dust particles stuck to solar panels, reducing their efficiency and preventing batteries from being fully charged.

"The panels can be readjusted so as fewer dust particles could get in. Brushing them off still poses a challenge - there are no unambiguous solutions as to that. Our Lunokhod-2 ran into trouble in the early 1970s.

"It tilted to one side and scooped dust which covered the solar panels and eventually shut it down. A lunar rover needs motion planning algorithms that reduce the risk of such misfortunes," said Academician of the Russian Academy of Cosmonautics Alexander Zheleznyakov.

Russian space scientists will analyze what's happened to Jade Rabbit, though information is scarce, and perhaps make some adjustments in Luna-25, he said.

The lunar night will be over soon. It will be getting warmer and by February 8-9 Jade Rabbit should be waking up. If that fails to happen, the mission will still be a success. The rover's landing platform appears to be OK. Among its research gear is an ultraviolet telescope that will conduct the first ever astronomical observations from the Moon's surface.

Source: Voice of Russia