Lunar rover wakes up after near-death experience
BY STEPHEN CLARK
Posted: February 14, 2014
China's Yutu moon rover woke up this week and radioed Earth after worries the mobile research platform would succumb to frigid temperatures during the two-week lunar night, but officials say the robot is still malfunctioning.
Ground controllers confirmed they received signals from the rover Wednesday, two days after the rover's scheduled wakeup.
The rover was struck by a mechanical anomaly before nightfall Jan. 25, forcing the craft to go into sleep mode without proper precautions against nighttime temperatures reaching as low as minus 180 degrees Celsius, or minus 292 degrees Fahrenheit.
State media did not describe details of the problem, and Xinhua reported Thursday engineers are still trying to identify the cause of the technical glitch, which left many observers concerned the roving explorer would not wake up.
The rover, dubbed Yutu or "jade rabbit," is designed to hibernate during lunar nights, when the sun slips below the horizon for two weeks and temperatures plunge cold enough to damage sensitive electronic circuits and avionics systems inside the spacecraft.
During hibernation, Yutu is unable to charge its batteries or communicate with Earth.
Chinese designers installed small radioisotope heaters fueled by plutonium to keep critical components warm at night. Before each sunset, Yutu is supposed to retract its camera mast and fold two solar panels over the rover's body.
"Now that it is still alive, the rover stands a chance of being saved," Pei said in a report by Xinhua.
Yutu was designed to operate on the moon for three months. The rover touched down Dec. 14 and drove off its four-legged landing platform to begin exploring the bleak, cratered terrain in the moon's Mare Imbrium region, one of the dark spots on the moon as seen from Earth.
The rover has logged about 100 meters, more than 300 feet, of driving since the mid-December landing. Controllers spent the initial days of the mission using the lander and rover to take pictures of each other.
Yutu used a mechanical scoop to sample the lunar soil earlier this month, according to state media, and it studied the moon's underground structure with a ground-penetrating radar. The robot used X-ray and near-infrared spectrometers to measure the composition of lunar rocks.
Engineers also established a radio communications link between the four-foot-tall rover and its stationary landing platform. Chinese media have reported no problems with the four-legged lander other than the failure of its main camera, which was only designed to function for a few weeks.
The Chang'e 3 lander has its own suite of instruments including an ultraviolet telescope to observe Earth's plasmasphere and conduct the first long-term astronomical observations from the lunar surface.
Yutu is part of China's third lunar mission. Named Chang'e 3, the project achieved the first soft landing on the moon since 1976 and followed two Chinese lunar orbiters launched in 2007 and 2010.
Follow Stephen Clark on Twitter: @StephenClark1.