Tag Archives: Yutu

After 31 months, Jade Rabbit ceases operation

China’s first lunar rover, Yutu (Jade Rabbit in English) has finally ceased operations after 31 months.

The rover stalled shortly after it moved away from its lander, Chang’e 3, but its instruments were still able to gather data, and they did so for about 10 times longer than originally planned.

China releases images from lunar rover and lander

Yutu on the Moon

China has made available a new batch of very cool images taken by its Chang’e 3 lander and Yutu rover, and Emily Lakdawalla at the Planetary Society has figured out how to view them.

In a recent guest blog post, Quanzhi Ye pointed to the Chinese version of the Planetary Data System, and shared the great news that Chang’e 3 lander data are now public. The website is a little bit difficult to use, but last week I managed to download all of the data from two of the cameras — a total of 35 Gigabytes of data! — and I’ve spent the subsequent week figuring out what’s there and how to handle it.

So, space fans, without further ado, here, for the first time in a format easily accessible to the public, are hundreds and hundreds of science-quality images from the Chang’e 3 lander and Yutu rover. I don’t usually host entire data sets (PDS-formatted and all) but I made an exception in this case because the Chinese website is a bit challenging to use.

The image above is a cropped version of Yutu, taken by the lander. Be sure and go to the link to see the full image as well as others.

Yutu still operational after two years

Despite an inability to move, China’s rover Yutu has now set the longevity operational record for rover on the Moon.

Yutu was deployed and landed on the moon via China’s Chang’e-3 lunar probe in 2013, staying longer than the Soviet Union’s 1970 moon rover Lunokhod 1, which spent 11 months on the moon. Its operations have streamed live through Sina Weibo, a Chinese microblogging site, and its Weibo account has nearly 600,000 followers.

Yutu experienced a mechanical control abnormality in 2014, but it was revived within a month and, though it is unable to move, it continues to collect data, send and receive signals, and record images and video.

Yutu reveals a complex lunar geology

The uncertainty of science: The Chinese lunar rover Yutu has uncovered a much more complicated geology history than previously predicted at its landing site on the moon.

Those data paint a detailed portrait of the Chang’e 3 landing site, which sits just 165 feet (50 m) away from a 1,475-foot-wide (450 m) crater known as C1. C1 was gouged out by a cosmic impact that occurred sometime between 80 million and 27 million years ago, the study authors said.

Yutu studied the ground it rolled over, characterized the craters it cruised past and investigated an oddly coarse-textured rock dubbed Loong, which measures about 13 feet long by 5 feet high (4 by 1.5 m). Overall, the rover’s observations suggest that the composition of its landing site is quite different from that of the places visited by NASA’s Apollo missions and the Soviet Union’s Luna program.

The rover found 9 distinct layers, suggesting numerous and different past events that layered the surface.

Yutu lives!

Despite an engineering failure that has prevented it from roving after only a few days on the Moon, the Chinese lunar rover Yutu continues to reawaken after each long lunar night, surviving now far longer than its planned three month lifespan.

Since the rover arrived in late 2013, it has now functioned in the hostile lunar environment for more than a year. This, along with other successful long missions, suggests that Chinese space engineering has matured to a point that it has the ability to achieve some significant long term goals.

Yutu is slowly dying

China’s lunar rover Yutu, unable to move since its first few weeks on the moon, is slowly dying.

The rover is currently in good condition and works normally, but its control problem persists, said Yu Dengyun, deputy chief designer of China’s lunar probe mission. “Yutu has gone through freezing lunar nights under abnormal status, and its functions are gradually degrading,” Yu told Xinhua at an exclusive interview. He said that the moon rover and the lander of the Chang’e-3 lunar mission have completed their tasks very well. The rover’s designed lifetime is just three months, but it has survived for over nine.

As China’s first planetary rover mission, the limited roving success of Yutu is well balanced by its ability to continue functioning on the lunar survey for so long. The engineering data obtained from this mission will serve Chinese engineers well as they plan future missions.

Was Yutu stopped by rough ground?

One of the designers of the Chinese lunar rover Yutu said in a news interview today that the rocky nature of the Moon’s surface, far rougher than expected, was what caused it to stall.

The rover was tested in Beijing, Shanghai and the desert in northwestern China before its launch, but the terrain of the landing site proved to be much more rugged than expected, said Zhang Yuhua, deputy chief designer of the lunar probe system for the Chang’e-3 mission. “It is almost like a gravel field.”

Data from foreign researchers projected that there would be four stones, each above 20 cm, on average every 100 square meters, but the quantity and size of the stones that Yutu has encountered has far exceeded this expectation, Zhang said in an exclusive interview with Xinhua. “Experts’ initial judgement for the abnormality of Yutu was that the rover was ‘wounded’ by colliding with stones while moving,” she said. [emphasis mine]

The implication of the highlighted quote is that it isn’t their fault, it was the fault of those evil Americans and Russians who incorrectly estimated the roughness of the ground. This article also doesn’t fit the information released when Yutu first stalled, where they explained that their problem was partly an inability to retract equipment in preparation for lunar night. While this story could be true, it isn’t the whole story.

A profile of the designer of China’s Yutu lunar rover.

A profile of the designer of China’s Yutu lunar rover.

The details about Jia Yang’s life as well as some of the challenges he faced building the rover and other spacecraft for China is most interesting. I also suspect that if we pay close attention we will see his name pop up again in connection with future missions.

As China’s Yutu lunar rover barely continues to survive, unable to move, its scientists prepare to publish their results.

As China’s Yutu lunar rover barely continues to survive, unable to move, its scientists prepare to publish their results.

But other systems and scientific instruments — a panoramic camera, infrared and X-ray spectrometers and a ground-penetrating radar — are operating normally, says Zheng: “The rover can still carry out measurements from the fixed location and send scientific data to the ground station.” …

Yutu’s penetrator radar has detected several layers underneath its path, says Long Xiao, a planetary scientist at China University of Geosciences in Wuhan. Under the surface soil, known as regolith, it found a layer of debris from a crater-forming impact and two layers of lava flows, made of basalt.

Though the rover lost its ability to rove within days of landing on the Moon, the mission is certainly an overall success for China. When they send their next rover to the Moon this first experience will serve them very well.

China claimed today that its lunar rover Yutu is still alive on the Moon.

China claimed today that its lunar rover Yutu is still alive on the Moon.

The rover is still able to send data back to Earth using the Chang’e 3 probe that delivered it, the official Xinhua news agency said, citing Li Bengzheng, deputy commander-in-chief of China’s lunar program. But the buggy’s wheels and the solar panel designed for thermal insulation during the frozen lunar nights no longer work, Li said. The craft’s functionality is progressively deteriorating “with each lunar night,” Li said.

What is significant here is that though the rover’s ability to rove failed much sooner than planned, its longevity now means that much of their engineering for future missions will work.

China’s Yutu rover is still functioning but cannot move.

China’s Yutu rover is still functioning but cannot move.

Last week Yutu and its companion spacecraft, the Chang’e 3 Moon lander, awoke from a period of dormancy after the frigid, two-week lunar night — the third awakening since landing on 14 December, Chinese scientists said this week at the Lunar and Planetary Science Conference in The Woodlands, Texas. The probes continue to gather data and send it back to Earth.

But Yutu may never move more than the 100–110 metres it has already travelled from its landing site — in the Mare Imbrium. Mission officials had hoped that Yutu would travel to the rim of a nearby crater and explore it, but a mechanical failure in Yutu’s drive system has stilled the rover since late January.

I wish they would get their story straight. This article suggests that the problem wasn’t in the circuit that controls the storage of equipment during the long lunar night, as reported previously, but in the system that actually moves the rover.

It also appears from the story above that scientists were disappointed by the amount of information released at the Texas conference.

China finally reveals Yutu’s problem: the failure of a control circuit prevents it from storing its solar panels during lunar night.

China finally reveals Yutu’s problem: the failure of a control circuit prevents it from storing its solar panels during lunar night.

A functioning control circuit is required to lower the rovers mast and protect the delicate components and instruments mounted on the mast from directly suffering from the extremely harsh cold of the Moon’s recurring night time periods. “Normal dormancy needs Yutu to fold its mast and solar panels,” said Ye. The high gain communications antenna and the imaging cameras are [also] attached to the mast. They must be folded down into a warmed electronics box to shield them from the damaging effects of the Moon’s nightfall when temperatures plunge dramatically to below minus 180 Celsius, or minus 292 degrees Fahrenheit.

Though Chinese engineers say that Yutu is still having problems, they have gotten a signal from it.

It’s alive! Though Chinese engineers say that Yutu is still having problems, they have gotten a signal from it.

The reports continue to be vague. It appears that they are in communication with the rover, which is good, but cannot get it to do what they need or want it to do, which is bad.

Something is wrong with China’s lunar rover.

Something is wrong with China’s lunar rover.

The link above is exceedingly short, one sentence, and describes the problem as an “abnormity” which makes no sense, so there is as yet no clear idea what the issue is.

A longer report is here, but it doesn’t add much, other than the “abnormality” is related to “mechanical control.”

NASA’s Lunar Reconnaissance Orbiter has spotted China’s Yutu rover on the Moon’s surface.

NASA’s Lunar Reconnaissance Orbiter has spotted China’s Yutu rover on the Moon’s surface.

These images confirm that the rover landed in Mare Imbrium, not Sinus Iridum, the originally announced landing site and the site that many Chinese news sources continue to report as the landing site.

China’s rover about to go to sleep for the long lunar night.

China’s rover is about to go to sleep for the long lunar night.

According to Wu Fenglei of the Beijing Aerospace Control Center, the lander will “go to sleep” at about 7 a.m. on Christmas Day and the moon rover, Jade Rabbit, will fall asleep at about 1 a.m. on Boxing Day. The forthcoming lunar night, expected to begin on Dec. 26, will last for about two weeks, experts with the center estimated. During their “sleep”, both lander and rover will have to tolerate minus 180 degrees Celsius. Scientists tested the lander early Tuesday to ensure it can stand the temperature drop. Both lander and rover are stable, said Wu, adding they have completed a series of scientific tasks in the past two days.

This report states the rover landed in Sinus Iridum, the original announced landing site, contradicting other reports that said the lander came down in Mare Imbrium.

After a successful soft landing, China’s lunar rover Yutu has successfully rolled onto the lunar surface.

The competition heats up: After a successful soft landing, China’s lunar rover Yutu has successfully rolled onto the lunar surface.

The real significance of this mission is that China has now demonstrated that it has developed the engineering to achieve a controlled soft landing on another world. With this technology, they can move on to building a manned lander, something only the U.S. has been able to accomplish.

Chang’e 3 and Yutu – The tale of a beautiful goddess and her rabbit on the Moon.

Chang’e 3 and Yutu – The tale of a beautiful goddess and her rabbit on the Moon.

In this case, the goddess and rabbit are Chinese robots exploring the Moon for science. The launch is scheduled for 1:30 am Monday in China, which is 12:30 pm Eastern Sunday in the U.S.

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