China's Chang'e 3 lunar lander and Yutu moon rover have awakened from weeks of hibernation and resumed their scientific work, official news media reported Sunday. The resumption of operations after the two-week-long lunar night addresses the mission's last major challenge.
The Xinhua news agency said the six-wheeled Yutu rover — which was named after a "Jade Rabbit" in Chinese mythology — was the first to wake up, on Saturday. The Chang'e 3 lander, named after the moon goddess who kept Yutu by her side, followed on Sunday.
Both spacecraft draw most of their power from solar arrays, which means they must conserve power when their landing site in the Bay of Rainbows, or Sinus Iridum, goes into darkness. They're equipped with plutonium-powered backup batteries to keep the electronics warm amid overnight temperatures that go as low as 292 degrees below zero Fahrenheit (-180 degrees Celsius).
"During the lunar night, the lander and the rover were in a power-off condition, and the communication with Earth was also cut off," Zhou Jianliang, chief engineer of the Beijing Aerospace Control Center, said in a report from Xinhua.
Chang'e 3 landed on Dec. 14 and rolled out a ramp to deliver Yutu to the surface for an initial round of reconnoitering — and then both spacecraft went into hibernation on Dec. 25-26. From now on, the spacecraft are expected to split their time into roughly two-week rounds of waking and sleeping.
Chang'e 3 is the first mission to operate on the surface of the moon since 1976, when the Soviets' Luna 24 robotic spacecraft gathered up samples of moon dirt and sent them back to Earth. The rover is due to operate for at least three months — collecting and analyzing lunar samples, and mapping the subsurface with ground-penetrating radar. The lander is built to make astronomical observations for at least a year, drawing upon optical telescope gear and an extreme ultraviolet camera.
Both spacecraft are equipped with cameras and sent an initial round of snapshots back to Earth before their hibernation.
China is already making plans for a 2017 mission that would bring samples back from the moon.
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Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the NBC News Science Facebook page, following @b0yle on Twitter and adding +Alan Boyle to your Google+ circles. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.