Tag Archives: Chang’e 4

Yutu-2 completes 20th lunar day on Moon

The new colonial movement: The Chinese lunar rover Yutu-2 has completed its 20th lunar day on the farside of the Moon, and has now been put in sleep mode for the long lunar night.

Yutu 2 continued on its planned journey to the northwest of the lander, according to the China Lunar Exploration Program (CLEP). The rover covered 90 feet (27.64 meters) during the lunar day to make a total of 1,610 feet (490.9 m) of roving since setting down on the far side of the moon in January 2019.

The article at the link includes some images, including visual data from the ground-piercing radar that suggests at least four layers in the lunar subsurface.

Yutu-2 travels 62 feet during 19th lunar day

According to the official Chinese press, Yutu-2 traveled another 62 feet during its 19th lunar day on the far side of the Moon.

I did not get that number from the article, which was written to imply falsely that the rover’s total travel distance since landing (463 meters) was what it did during this single lunar day. To get the real travel distance I took the total from the previously reported total travel distance and figured the difference.

If you want to be educated to the absolutely useless nature of a state-run press, put both links above in separate tabs and compare. You will discover that other than some very minor changes, the new news story is essentially a cut-and-paste of the previous. Which by the way is a cut-and-paste of the last few reports. They don’t even bother to make believe (like the leftist American mainstream media) that they are giving us some information. They simply don’t.

Yutu-2 to resume travels after day of rest

The new colonial movement: After lunar day of no activity, China has reactivated its Yutu-2 rover on its 19th lunar day on the far side of the Moon.

The Yutu 2 rover had remained stationary during lunar day 18 (May 16-29), while teams back on Earth upgraded ground stations in preparation for the Tianwen-1 Mars mission, due to launch in late July or early August. Upgrades to the tracking and command facilities at Jiamusi, northeast China, and Kashi in the northwest were completed June 13 according to CLEP, meaning normal roving service can now resume.

While the rover has been stationary, the Yutu 2 science team have identified a nearby crater for examination. The 4-foot-wide (1.3 meters), 8-inch-deep (20 centimeters) crater contains reflective material which may be similar in nature to suspected impact melt glass the rover discovered last year. After checking out the crater, Yutu 2 will continue its journey northwest from the Chang’e 4 landing site. Yutu 2 has driven a total of 1,469 feet (447.68 meters) since setting down on the far side of the moon in January 2019.

Generally Yutu-2 has averaged about a hundred feet for each lunar day of actual travel.

Yutu-2 awakes for 18th lunar day on far side of the Moon

The new colonial movement: Chinese engineers have awakened both Chang’e-4 and Yutu-2 for their eighteenth lunar day on far side of the Moon.

The report is from China’s state-run propaganda news services, so it tells us little else. Based on past reports, Yutu-2 will likely continue its slow progress to the northwest, probably traveling about another 75 feet during this lunar day.

Yutu-2 and Chang’e-4 complete 17th lunar day on Moon

According to China’s state-run propaganda news agency, Yutu-2 and Chang’e-4 have successfully completed their 17th lunar day on the far side of the Moon, and have been put into sleep mode for the coming long lunar night.

Yutu-2 apparently traveled another 23 meters (about 75 feet) to the northwest.

Other than that single tidbit, the news report is nothing more than garbage Chinese propaganda, some of which is merely cut and pasted from earlier reports.

Yutu-2 and Chang’e-4 complete 16h lunar day on Moon

China’s Yutu-2 rover and Chang’e-4 lander have now successfully completed their sixteenth lunar day on the far side of the Moon, and have been put into hibernation for the long lunar night.

This means that both spacecraft have now worked longer on the Moon than any previous mission.

The news report, from China’s state-run press, provides only one real piece of information: Yutu-2 has now traveled a total of 424.45 meters (1,393 feet), which means it traveled about 24 meters (79 feet) during this sixteenth lunar day.

Their goal is to reach a different geological area of basalt a little over a mile away, a journey they say will take about a year.

I question that time frame however. Yutu-2 has averaged about 88 feet travel per lunar day. To go a mile at that pace will take about sixty lunar days, which is equivalent to between four and five years. The difference might be because the information at the second link is a bit unclear, and that they hope to begin entering the basalt region much sooner.

We shall just have to wait and see.

Chang’e-4 and Yutu-2 awake for 16th lunar day

Engineers have reactivated their Chang’e-4 lander and Yutu-2 rover on the far side of the Moon to begin their sixteenth lunar day of operations.

The article provides some good information about the future plans for Yutu-2, including some maps showing its overall travels and planned route.

[A] new plan has been formulated for the Yutu 2 rover, which has already provided insights into the composition of the surface and what lies below. Li Chunlai, deputy director of the National Astronomical Observatories of China (NAOC), told the state-run news outlet CCTV+ that the Yutu 2 team are targeting distant areas.

Yutu 2 has been driving across an area covered in ejecta from impact craters, but reaching new ground would be insightful. “If it can enter a basalt zone, maybe we can better understand [the] distribution and structure of ejecta from meteorite impacts,” Li said. “The distance may be 1.8 kilometers [1.1 miles]. I think it may take another one year for the rover to walk out of the ejecta-covered area.”

The rover has been averaging less than a hundred feet of travel per lunar day, so going 1.1 miles will take some time. Kudos however for the rover’s science team for deciding to attempt it. The decision reminds me of a similar decision by the Opportunity rover team to send their rover to Endeavour Crater, miles from their landing site. They made it, and thus explored a region no one ever expected the rover to reach.

Chang’e-4 and Yutu-2 complete 15th lunar day on Moon

Chinese engineers have put both Chang’e-4 and Yutu-2 into sleep mode after successfully completing their fifteenth lunar day on the far side of the Moon.

According to the story from China’s state-run press, Yutu-2 has now traveled just under 400 meters, or about 1,311 feet. We do not have a map outlining its total path, though past data suggests it has generally traveled westward away from Chang’e-4. Other than this detail, the story provides little other information.

Chinese scientists publish radar results from Chang’e-4 lander

Layers as seen below ground by Chang'e-4 radar

The new colonial movement: Chinese scientists today published their first ground-penetrating radar results from their Chang’e-4 lander on the far side of the Moon.

Using a ground-penetrating radar instrument on Chang’e-4, researchers have found that the rover is likely sitting on different layers of ejecta—debris from multiple impacts over time that rained down at high velocities to blanket the lunar surface and now fill the crater. “[We] see a very clear sequence of [layers],” says Elena Pettinelli of Roma Tre University in Italy, one of the paper’s co-authors.

The rover’s radar instrument was able to penetrate up to 40 meters below the surface of the moon, more than twice the distance achieved by its predecessor, the Chang’e-3 mission, which landed on the lunar near side in December 2013. Data from the latest mission show three distinct layers beneath the rover: one made of lunar regolith, or soil, down to 12 meters; another made of a mix of smaller and larger rocks down to 24 meters; and a third with both coarse and fine materials extending the rest of the 40-meter depth.

The figure to the right comes from the paper [pdf] Though the layers have not been dated, their differences suggest different past events in the formation of this surface.

These results are excellent, but they also have many uncertainties. Radar can tell you a lot, but the only way you can really ever know anything about what’s below ground is to go there and actually do some digging.

Chang’e-4 and Yutu-2 awake for their 15th lunar day

The new colonial movement: Engineers have reactivated China’s Chang’e-4 lander and Yutu-2 rover for their 15th lunar day on the far side of the Moon.

As usual, the story in China’s state-run press reveals little. This time however it does mention that Yutu-2 will continue traveling to the west, first to the northwest and then to the southwest.

Yutu-2 and Chang’e-5 complete 14th lunar day

China’s Yutu-2 rover and Chang’e-5 lander have successfully completed their fourteenth lunar day of operations on the far side of the Moon, and have gone into hibernation.

The report from China’s state-run news agency is, as usual, decidedly uninformative. It is written to make it appear that Yutu-2 traveled 367 meters during this most recent lunar day, when in truth that is the total distance since landing. In comparing this total with the total at the end of the thirteenth lunar day, we find that Yutu-2 actually traveled only ten meters.

The report also provided no other information about where the rover went, or what it has been doing, other than saying the rover and its instruments operated as “planned.” The article did not even include a picture, either new or old.

It is a shame that China operates in this secret way. They are doing good stuff on the Moon. If they touted it proudly to the world, in as much detail as possible, they would do themselves far more good.

Yutu-2 completes 13th lunar day

China’s Yutu-2 lunar rover and its lander Chang’e-4 have completed their thirteenth lunar day on the far side of the Moon and have been placed in sleep mode.

During the twelve lunar day the rover traveled about 12 meters, or about 40 feet.

The rover has found materials from deep inside the moon that could help unravel the mystery of the lunar mantle’s composition and the formation and evolution of the moon and the earth. Using data obtained by the visible and near-infrared spectrometer installed on Yutu-2, Chinese scientists found that the lunar soil in the landing area of the Chang’e-4 probe contains olivine and pyroxene which came from the lunar mantle deep inside the moon.

Due to the complicated geological environment and the rugged and heavily cratered terrain on the far side of the moon, the rover drives slowly but steadily and is expected to continue traveling on the moon and make more scientific discoveries.

Chang’e-4 and Yutu-2 complete 12th lunar day

Chinese engineers have put both Chang’e-4 and Yutu-2 into dormant mode after completed their twelve lunar day on the far side of the Moon.

The article from the Chinese state-run press provides very little information, other than telling us that Yutu-2 traveled 345 meters, written in a way to imply that was the distance the rover traveled in this last lunar day. I think that is wrong, however. Based on the distances traversed during previous lunar days, and that the rover had traveled a total of 290 meters at the end of its tenth lunar day, I think this new number is the total distance traveled.

The article also does not say what the consequences will be for these two spacecraft now that the priority of their communications relay has shifted from communications to being a radio telescope.

It could be that the consequences will be minor, considering that both spacecraft are in sleep mode during the lunar nights and for high noon of the lunar day. During those periods the relay satellite could be devoted full time to radio astronomy and have no impact on the lander and rover.

Unfortunately China has not said.

China unfolds Dutch radio antennas on lunar relay satellite

Chinese engineers have unfolded and activated the Dutch radio antennas on Queqiao, their lunar relay satellite orbiting the Moon, an action that had been delayed because the lander Chang’e-4 and rover Yutu-2 had both exceeded their nominal mission on the surface.

The Chinese satellite was previously mainly seen as a communications satellite. However, the Chinese moon mission has by now achieved its primary goals. Consequently, the Chinese have redefined the satellite to be a radio observatory. As such, the Netherlands-China Low Frequency Explorer is the first Dutch-Chinese space observatory for radio astronomy.

Marc Klein Wolt, Managing Director of the Radboud Radio Lab and leader of the Dutch team, is happy: “Our contribution to the Chinese Chang’e 4 mission has now increased tremendously. We have the opportunity to perform our observations during the fourteen-day-long night behind the moon, which is much longer than was originally the idea. The moon night is ours, now.”

If Queqiao is now dedicated to being a radio antenna full time during the lunar night, I wonder if this means the Chinese are shutting down Chang’e-4 and Yutu-2. Up to now both spacecraft have only operated during the lunar night, which suggests that was the only time they could relay data. It is possible that data relay could take place at other times, and that the lander and rover can function autonomously, but I have my doubts.

Both Chang’e-4 and Yutu-2 functioned for twelve lunar nights, four times longer than planned, so shifting gears on Queqiao to do radio astronomy is not unreasonable. Unfortunately, the lack of transparency from China leaves us in the dark about the fate of Chang’e-4 and Yutu-2.

Chang’e-4 and Yutu-2 begin 12th lunar day

Chinese engineers have reactivated both their lunar lander, Chang’e-4, and its rover, Yutu-2, for their twelve lunar day on the far side of the Moon.

The lander woke up at 5:03 p.m. Thursday (Beijing Time), and the rover, Yutu-2 (Jade Rabbit-2), awoke at 0:51 a.m. the same day. Both are in normal working order, according to the Lunar Exploration and Space Program Center of the China National Space Administration.

No word on where Yutu-2 will be sent over then next two weeks.

Posting was light during the day today because Diane and I were on a hike that I needed to do for the upcoming planned second edition of my hiking guidebook, Circuit Hikes of Southern Arizona. My boss (me) allowed me to go, since this hike was not pure pleasure, but reconnaissance for one of my books.

Chang’e-4 and Yutu-2 complete 11th day on Moon

After successfully completing their eleventh lunar day on the far side of the Moon, Chinese engineers have put both Chang’e-4 and Yutu-2 back into dormant mode for the long lunar night.

Yutu-2 traveled another 28 meters during this eleventh lunar day. It is now about 218 meters to the west of Chang’e-4.

Chang’e-4 and Yutu-2 awake for 11th lunar day

Engineers have reactivated both Chang’e-4 and Yutu-2 to begin normal operations on their eleventh lunar day on the far side of the Moon.

As is usual for these reports from the state-run official media in China, the article provides little information. However, this article today from space.com provides an update on the “gel-like” material that Yutu-2 spotted in August.

While gaining the attention of the Yutu 2 team, the material does not appear altogether mysterious, as claimed by Chinese media.

Clive Neal, a lunar scientist at the University of Notre Dame in Indiana, told Space.com that the new image reinforces the previous suggestion that the material is broadly similar in nature to a sample of impact glass found during the Apollo 17 mission in 1972.

…Dan Moriarty, NASA Postdoctoral Program fellow at the Goddard Space Flight Center in Greenbelt, Maryland, has analyzed and processed the image, seeking clues as to its precise nature. While this compressed image lacks a lot of the useful information a raw image would contain, Moriarty said he could gain insights by adjusting parameters. “The shape of the fragments appears fairly similar to other materials in the area. What this tells us is that this material has a similar history as the surrounding material,” Moriarty said. “It was broken up and fractured by impacts on the lunar surface, just like the surrounding soil.

Overall, Yutu-2 has traveled about 950 feet or 290 meters westward from Chang’e-4 since it began roving at the start of the year.

Yutu-2 travels almost 300 meters on ninth lunar day

According to a story today in official Chinese state-run media, Yutu-2 traveled another 284.99 meters during its ninth lunar day on the surface of the Moon, and has now been placed in hibernation in order to survive the long lunar night.

The story provides no further information, including saying nothing about the strange and unusual material the rover supposedly spotted during this time period.

Yutu-2 and Chang’e-4 go to sleep again

Yutu-2's travels

Both Yutu-2 and Chang’e-4 have been put in dormant mode after completing their eighth lunar day on the far side of the Moon.

The article at the link provides a lot of new details about what both spacecraft have learned and done since they landed, including a nice detailed map showing Yutu-2’s exact path during those eight lunar days. The image to the right, reduced to post here, was taken by Yutu-2, and shows the rover’s tracks during what appears to be its seventh lunar day. It appears that the rover periodically stopped and did a pirouette, probably to obtain a 360 degree mosaic of the surrounding terrain.

Yutu-2’s travels have tended west from Chang’e-4, and on its eighth lunar day it continues that route, traveling 271 meters. After a period of short traveling days, they have now upped the distance traversed by a considerable amount. Since the planned nominal mission for both spacecraft had been three lunar days, both are demonstrating that the Chinese have figured out how to do this, and are now pushing Yutu-2 hard as a result.

The article vaguely describes some of the science obtained so far, but in general the Chinese remain tight-lipped about most of their discoveries.

Chang’e-4/Yutu-2 return to dormant mode for lunar night

According to one story in the Chinese press today, the science teams running Chang’e-4 and Yutu-2 on the far side of the Moon have now put both into dormant mode for the coming lunar night after completing their seventh lunar day.

What is intriguing about this short story is that while to lauds the work done by Chang’e-4 during that seventh lunar day, it says nothing about Yutu-2. Early comparable reports would have at least told us how far the rover moved during the lunar day. This time they say nothing at all about Yutu-2, other than it has been placed in dormant mode.

It could very well be that they had a problem with the rover. Sadly, China is not an open society. We can only wait for them to tell us.

The travels of China’s Yutu-2 rover on the Moon

Yutu-2 and Chang'e-4
Click for full image.

The Lunar Reconnaissance Orbiter (LRO) science team today released images that track the travels of China’s lunar rover Yutu-2 from its landing on January 30, 2019 through June 3, covering the rover’s first six lunar days on the Moon.

The image to the right, cropped, reduced, and annotated to post here, shows the relative positions of both spacecraft as of June 3, 2019. In the release they also included a gif movie showing the progression of Yutu-2’s movements since landing.

Once a month, LRO passes over the Chang’e 4 landing site, allowing LROC to capture a new image. LROC has now imaged the site five times (since the landing) and observed Yutu-2 to have traveled a total of 186 meters (distance measured using the rover tracks). If you squint, portions of the rover tracks are visible as a dark path in the images from April, May, and possibly June.

table of Yutu-2's movements through June 2019

The LRO release also included a table showing the distance Yutu-2 has traveled with each lunar day, shown on the right. The table does not include the 23 meters (75 feet) the rover traveled on its sixth lunar day. My estimate yesterday that Yutu-2 was traveling an average of about a 100 feet per day, with the distances per day shrinking with time, seems largely correct. During the rover’s fourth and fifth lunar days it moved very little, either because they had found something very interesting they wanted to inspect more closely, or they were moving more cautiously as the rover’s life extended past its planned lifespan of three lunar days.

On the sixth day however they increased their travels again, suggesting that either they had finished the observations at the previous location, or they had gained more confidence in the rover’s staying power.

Chang’e-4 and Yutu-2 awake for 7th lunar day

The new colonial movement: Chinese engineers have awakened both the Chang’e-4 lander and the Yutu-2 rover to begin work on their seventh lunar day on the Moon’s far side.

The text of this Chinese news report is almost identical to the text in the news report a month ago, when both spacecraft were awakened for the sixth lunar day. And as before, it tells us little.

What today’s story reveals is that Yutu-2 traveled only about 75 feet during the sixth lunar day. With an overall odometer reading of 695 feet, it appears it is averaging about 100 feet per lunar day, with the per day number dropping with time. Either the science team is becoming cautious, or they have had unstated issues that have slowed them down.

Still, the rover’s nominal mission was only three lunar days, so it is survived more than twice as long as designed.

Chang’e-4 and Yutu-2 wake up for sixth lunar day

China’s Chang’e-4 lander and Yutu-2 rover have been reactivated this week to begin observations during their sixth lunar day on the far side of the Moon.

According to the Chinese news source,

For the sixth lunar day, the lander’s neutron radiation detector and low-frequency radio detector will be restarted to conduct scientific tasks including particle radiation observation and low-frequency radio astronomical observation.

The rover’s panoramic camera, detection radar, infrared imaging spectrometer and neutral atom detector will be restarted during the sixth lunar day.

That’s about all we know. They have not released much information about the rover’s travels, nor have they released any detailed information about the data they have obtained.

Yutu-2 travels more than 600 feet during its fifth lunar day on the Moon

The Chinese press today revealed that during its fifth lunar day on the Moon’s far side China’s lunar rover Yutu-2 traveled about 623 feet.

Where exactly it went, and what it learned, they did not reveal. We will have to wait for Lunar Reconnaissance Orbiter images to learn the rover’s route.

They have now put both Yutu-2 and the lander Chang’e-4 into sleep mode for the long lunar night.

Chang’e-4 and Yutu-2 awaken for fifth lunar day

The new colonial movement: China’s lunar lander Chang’e-4 and rover Yutu-2 have been awakened to begin work for their fifth lunar day on the far side of the Moon.

According to the report from this official Chinese government news source, Yutu-2 has now traveled just under 600 feet from the lander. We know from Lunar Reconnaissance Orbiter (LRO) images taken during the rover’s second lunar day of travel that it had moved to the west, but we don’t really know much else beyond that. LRO has not released any new images, and the Chinese have not told us.

Yutu-2 and Chang’e-4 awake for fourth lunar day

The Chinese rover Yutu-2 and lander Chang’e-4 were awakened on March 30, 2019 to begin work for their fourth lunar day on the surface of the Moon’s far side.

The rover was designed to last for three lunar days, but much like NASA missions that regularly outlive their initial mandates, Yutu 2’s mission may stretch on longer, the Chinese space agency hopes. (The current rover’s predecessor, Yutu, lost its roving ability on its second day on the moon.)

The China Lunar Exploration Program, which heads up the mission, has not provided any details about its scientific plans for the fourth day of Chang’e 4, which is focused on exploring the far side of the moon and how it differs from the near side.

Based on the images taken by Lunar Reconnaissance Orbiter, it appears they will be heading west, following the smoothest route away from Chang’e-4. This will place Yutu-2 in an area of small craters.

Yutu-2 heads west!

LRO images of Yutu-2 on the Moon
Click for full image.

A new image from Lunar Reconnaissance Orbiter (LRO) shows the path taken by the Chinese lunar rover Yutu-2 during its second lunar day of travel on the Moon. The LRO images on the right, cropped and reduced in resolution to show here, compares the rovers position at the start and end of February. The white arrow indicates the rover, with its Chang’e-4 lander visible between the three craters to the east. As noted by the LRO science team:

LRO passes over any given place on the Moon at least once every month (in the daylight), allowing the westward progress of the Yutu-2 rover to be seen. At the end of February, Yutu-2 was 69 meters from it’s home base, the Chang’e 4 lander; LROC images show Yutu-2 made 46 meters of westward progress during the month of February.

It appears from these orbital images that they are taking the smoothest route, with the fewest obstacles, away from the lander.

Chinese lunar rover and lander enter their third lunar night

The Chinese lunar rover Yutu-2 and its lander Chang’e-4 have gone into hibernation as they enter their third lunar night on the far side of the Moon.

According to Chinese news reports, both spacecraft have now exceeded their nominal lifespan.

With all systems and payloads operating well, the Yutu-2 team will continue roving and science data collection on lunar day 4 of the Chang’e-4 mission, according to a [Chinese] announcement.

Yutu-2 added 43 meters to its overall drive distance in its third day of activities, continuing a path to the northwest of the landing site, which was recently named ‘Statio Tianhe’ by the International Astronomical Union. The rover just covered seven meters between waking for lunar day 3 on Feb. 28 and Mar. 3, during which time it navigated carefully toward a 20 centimeter diameter rock in order to analyze the specimen with an infrared and visible light spectrometer to determine its origin.

I am struck by how tentative the Chinese and their rover appear. The first Russian lunar rover, Luna 17, traveled 6.5 miles in eleven months. The second, Luna 21, traveled 23 miles in four months. At the pace Yutu-2 is setting, it will not come close to these mileages. Moreover, my impression of Chinese space technology in the past decade has been that it is quite robust. This tentativeness thus surprises me. Maybe because this is a government project they are simply covering their butts should something go wrong, and thus making believe the rover is more delicate than it really is.

As Scotty on Star Trek once said, “Always under predict, then over perform.” We might be seeing that pattern here.

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