China's moon rover Yutu has "woken" after its troubled dormancy but experts are still trying to find out the cause of its technical problems, a spokesman with the country's lunar probe program said on Thursday.
"Yutu has come back to life," said Pei Zhaoyu, after a period in which the rover's inactivity had threatened the completion of its mission.
Pei said Yutu, named after the pet of a lunar goddess in ancient Chinese mythology, has now returned to a state where it can receive signals as normal once again. But experts are still working to verify the cause of its mechanical control issues.
Yutu was designed to roam the lunar surface to survey the moon's geological structure and surface substances and look for natural resources. It was expected to work on the moon for at least three months.
But problems emerged before the rover entered its second dormancy on the moon on January 25 as the lunar night fell. Experts feared that it might never be able to function again.
"Yutu went to sleep under an abnormal status," Pei said, adding that experts had been concerned that it might not be able to survive the extremely low temperatures during the lunar night.
One night on the moon is about 14 days on Earth, during which the temperature falls below minus 180 degrees Celsius. During the lunar night, there is no sunlight to provide power to Yutu's solar panel. In this period, the rover is expected to stay in a power-off mode and communication with Earth is also cut off.
Yutu entered the first period of dormancy on December 26 as the mission's first lunar night arrived, and "woke up" on January 11. It was originally scheduled to wake up from the second dormant period on February 10.
"Now that it is still alive, the rover stands a chance of being saved," Pei said.
The news caused a splash in China's social networking circles.
On Sina Weibo, China's Twitter, the "Yutu Lunar Rover" account, which has followed the developments of the mission from a first-person perspective, posted its first update since the mechanical problems.
"Hi, anybody there?" it asked in a post, which prompted some 60,000 reposts and 40,000 comments within two hours.
"We are all here," one Weibo user replied.
"Hold on there, the whole country's got your back," another wrote.
Some joked about the rover being a "foodie" waking up for rice dumplings, a must-have delicacy for China's Lantern Festival that falls on Friday.
"Which would you prefer? Chocolates or rice dumplings?" asked one user with the screen name "shengkongtangjiang." This year's Lantern Festival falls on the same day as Valentine's Day.
Fans overseas also posted messages on Twitter.
"Makes me want to dance a jig," one user wrote minutes after the official @XHNews account posted the news that Yutu had woken up.
"PRC engineers & scientists shld [sic] be proud of their excellent work, & congratulations to them from all of humankind," another user named "jeffsonstein" said.
Lunar probe mission failures are not rare. In April 1962, U.S. lunar probe Ranger 4 crashed into the dark side of the moon after equipment failure prevented it from returning pictures and scientific data.
Yutu touched down on the moon's surface on December 15, several hours after China's lunar probe Chang'e-3 soft-landed on the moon on December 14.
Chang'e-3 is part of the second phase of China's lunar program, which includes orbiting, landing and returning to Earth. It follows the success of the Chang'e-1 and Chang'e-2 missions in 2007 and 2010.
China is the third country in the world to successfully soft-land on the moon after the United States and the Soviet Union.
(Xinhua News Agency February 13, 2014)