Tag: Chang’e-6

Chinese scientists say the lunar far side appears drier than the near side

10:17 am

Map of water measurements of lunar samples
Click for original image.

Based on a comparison of samples brought back by two Chinese unmanned lunar landers, Chinese scientists believe the lunar far side contains far less water in its mantle than the near side.

…the research team focused on analyzing water content and hydrogen isotopes in melt inclusions and apatite within [Chang’e-6] mare basalts—the first samples returned from the farside SPA Basin.

The team’s results indicate that the parent magma of these basalts contain 15–168 μg.g⁻¹ of water. Additionally, the team estimated that the mantle source of the CE6 basalts has a water content of 1–1.5 μg.g⁻¹, significantly lower than that of the nearside mantle. This disparity points to a potential hemispheric dichotomy in the Moon’s internal water distribution, mirroring many of the asymmetrical features observed on the lunar surface.

The map to the right, figure 1 in the scientists’ paper, shows the water content from the samples that have so far been brought back from the Moon. Note how the Chang’e-6 sample shows far less water content than all the near side samples.

Note however also that this is just one data point from the far side. To confirm these conclusions will require many more samples.

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China: samples from the near and far sides of the Moon are different

8:53 am

Scientists studying the lunar samples brought back from China’s Chang’e-6 mission to the far side of the Moon have determined that the different environments create differences in the surface material.

The study found that the solar wind exposure time of the Chang’e-6 samples was close to the minimum observed in the Apollo 11 samples, lower than that of the other Apollo samples, and slightly shorter than that of the Chang’e-5 samples. However, surprisingly, the npFe⁰ grain sizes in the Chang’e-6 samples were larger. “This might suggest that solar wind radiation in this region leads to more pronounced segregation and aggregation of iron,” she noted. These exciting new results add to the growing evidence that space weathering on the lunar farside may differ from that on the nearside, and, contrary to previous findings from Apollo and Chang’e-5 samples, solar wind radiation plays a more dominant role in the space weathering process on the lunar farside.

There are differences in the solar wind’s influence on different regions of the Moon. During each synodic month, the near side of the Moon enters Earth’s magnetotail, where the protection afforded by Earth’s magnetic field reduces its exposure to the solar wind; in contrast, the farside is continuously exposed to direct solar wind radiation. Moreover, due to orbital dynamics, different locations on the Moon experience varying impact velocities from cometary and asteroidal meteoroids. The relative velocity between the Moon’s surface and impacting meteoroids changes with the lunar phase: during a full moon, when the Moon and meteoroids move in the same orbital direction, the relative velocity increases; the opposite occurs during a new moon.

That there are differences between samples from the Moon’s two hemisphere should not a surprise. Confirming and characterizing those differences however is good.

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Analysis of Chang’e-6’s lunar samples suggest the giant impact that caused Aitken Basin occurred 2.83 billion years ago

10:33 am

Chang'e-6's landing site
Click for original image of Chang’e-6 on the Moon

In a paper published in mid-November, Chinese scientists have concluded that — based on their analysis of the lunar samples returned by their Chang’e-6 spacecraft — the giant impact that created the 1,600-mile-wide South Pole-Aitken Basin on the Moon occurred about 2.83 billion years ago.

This conclusion is based both on the dating of the samples as well an analysis of the cratering rate on the Moon. It also suggests the landing site as well as Aitken basin were volcanically active for longer than previous predictions. Overall, scientists believe most volcanic activity on the Moon ceased around three billion years ago.

As noted in the paper, the near and far sides of the Moon are very different.

The Moon has a global dichotomy, with its near and far sides having different geomorphology, topography, chemical composition, crustal thickness, and evidence of volcanism. Volcanic eruptions flooded parts of the surface with lava, producing rocks known as mare basalts, which are more common on the nearside (4), where they cover ~30% of the surface compared to 2% of the farside.

The farside’s crust is also thicker, though under Aitken Basin the difference largely disappears.

This first precise dating for the far side is the first step for understanding why the Moon’s hemispheres are so different. Though many theories exist, none can be considered definitive because we so far have only one data point for the far side.

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China: Chang’e-6 collected more than four pounds of material from Moon

9:11 am

According to China’s state-run press today, its Chang’e-6 sample return mission collected 1,953.2 grams, more than four pounds, from the Aitkin Basin on the far side of the Moon.

Based on preliminary measurement, the Chang’e-6 mission collected 1,935.3 grams of lunar samples, according to the CNSA. “We have found that the samples brought back by Chang’e-6 were more viscous compared to previous samples, with the presence of clumps. These are observable characteristics,” Ge Ping, deputy director of the CNSA’s Lunar Exploration and Space Engineering Center, who is also the spokesperson for the Chang’e-6 mission, told the press at the ceremony.

Researchers will then carry out the storage and processing of the lunar samples as planned and initiate scientific research work.

If all goes as plans, they will be ready to begin distributing samples for study to Chinese researchers in about six months.

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Chang’e-6 sample return capsule opened in China

10:27 am

According to China’s state-run press, the return capsule carrying samples from the far side of the Moon was opened yesterday “during a ceremony at the China Academy of Space Technology under the China Aerospace Science and Technology Corporation in Beijing.”

No other details were released. The pictures at the link appear to show engineers removing an internal capsule from inside the return capsule, which makes sense. For many scientific reasons the actual samples must be kept sealed from the Earth’s atmosphere in order to make sure they are not contaminated. The actual lunar material will not be exposed and touched until it is placed inside a very controlled environment.

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Chang’e-6 brings back the first lunar samples from Moon’s far side

9:10 am

Engineers inspecting and opening Chang'e-6 return capsule
Engineers inspecting and opening Chang’e-6’s
sample return capsule after landing today.
Click for original image.

According to China’s state-run press, the sample return capsule of its Chang’e-6 lunar mission successfully landed today in the inner Mongolia region of China, bringing back the first lunar samples from Moon’s far side.

Under ground control, the returner separated from the orbiter approximately 5,000 km above the South Atlantic. The capsule entered the Earth’s atmosphere at about 1:41 p.m. at an altitude of about 120 km and a speed of nearly 11.2 km per second. After aerodynamic deceleration, it skipped out of the atmosphere and then began to glide downwards, before re-entering the atmosphere and decelerating for a second time.
At around 10 km above the ground, a parachute opened, and the returner later landed precisely and smoothly in the predetermined area, where it was recovered by a search team.

The returner is set to be airlifted to Beijing for opening, and the lunar samples will be transferred to a team of scientists for subsequent storage, analysis and study, said the CNSA. [emphasis mine]

The highlighted sentence is important. China has now successfully flown this atmospheric skip maneuver twice on returning from the Moon. Though both missions were unmanned, the technical knowledge gained from these flights is critical for their plans to send astronauts to the Moon in the next few years.

I have embedded China’s broadcast of the landing below. The sample capsule will now be carefully opened and the samples distributed first to Chinese scientists and later to China’s various partners in its lunar base project. The samples themselves came from a small mare region on the edge of Apollo Crater inside South Aitken Basin, one of the largest impact basins on the Moon. It is thus hoped that the samples were excavated from deep within the Moon during the impact, and will provide new data on the Moon’s make-up and history.
» Read more

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Are Chang’e-6’s lunar samples on the way back to Earth?

9:30 am

In Friday’s June 21, 2024 quick links, changes to lunar orbit of China’s Chang’e-6 sample return spacecraft were detected by ham operators. As I noted, “It isn’t clear whether this was the previous orbit adjustment, a new one, or the burn that would send the sample return capsule back to Earth.”

According to Space News today, the spacecraft with the samples is on its way back to Earth, based on additional information detected by amateurs. China however has released no information on the status of the spacecraft.

Upon return to Earth, the reentry capsule is expected to touch down at Siziwang Banner, Inner Mongolia during an half-an-hour long window opening at 1:41 a.m. Eastern (0541 UTC) June 25. The information is according to airspace closure notices. CNSA has not openly published timings of mission events in advance.

Earlier reports (which I can’t find now) had said the return was tentatively scheduled for June 25, 2024, so this Space News report makes sense. The lack of information from China is par for the course.

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Lunar Reconnaissance Orbiter snaps picture of Chang’e-6 on far side of the Moon

10:23 am

Chang'e-6's landing site
Click for original image of Chang’e-6 on the Moon

The science team running Lunar Reconnaissance Orbiter (LRO) have now released an image of China’s Chang’e-6 lander on far side of the Moon, taken on June 7, 2024 one week after the spacecraft touched down.

Chang’e 6 landed on 1 June, 2024, and when LRO passed over the landing site almost a week later, it acquired an image showing the Chang’e 6 lander on the rim of an eroded ~50 meter diameter crater.

The LROC team computed the landing site coordinates as 41.6385°S, 206.0148°E, at -5256 meters elevation relative to the average lunar surface, with an estimated horizontal accuracy of plus-or-minus 30 meters.

The overview map to the right, showing the entire far side of the Moon, shows that picture as the inset in the lower left, cropped to post here. The black and white dot in the center is Chang’e-6’s lander, with the surrounding brightened ground showing the blast area produced by the engines during touchdown.

According to the LRO press release, the large dark area that surrounds the lander — as seen in the wider inset in the upper right — is a “basaltic mare deposit” — similar to the vast dark frozen lava seas evident to our own eyes on the near side of the Moon.

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Lunar samples transferred to Chang’e-6 return vehicle

7:54 am

According to China’s state-run press, the ascent vehicle has docked with the Chang’e-6 orbiter and successfully transferred its lunar samples to the return spacecraft that will bring those samples back to Earth.

The ascender of China’s Chang’e-6 probe successfully rendezvoused and docked with the probe’s orbiter-returner combination in lunar orbit at 2:48 p.m. (Beijing Time) on Thursday, the China National Space Administration (CNSA) announced.

The container carrying the world’s first samples from the far side of the moon had been transferred from the ascender to the returner safely by 3:24 p.m., the CNSA said.

That return is scheduled for later this month. In the meantime the orbiter will adjust its position in preparation for sending the return capsule back.

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Chang’e-6 ascender carrying lunar samples lifts off Moon

8:52 am

Chang'e-6's robot arm grabbing ground samples
Chang’e-6’s robot arm grabbing ground samples.
Image is a screen capture from mission control
main screen. Click for original.

Early today the ascender of China’s Chang’e-6 lunar probe lifted off the surface on the Moon’s far side, carrying the samples it had obtained both by drilling and the use of a robot arm.

The ascender took off at 7:38 a.m. (Beijing Time) from the moon’s far side. A 3,000-newton engine, after working for about six minutes, pushed the ascender to the preset lunar orbit, according to the CNSA.

The Chang’e-6 probe, comprising an orbiter, a lander, an ascender and a returner — like its predecessor Chang’e-5 — was launched on May 3. The lander-ascender combination, separated from the orbiter-returner combination on May 30, touched down at the designated landing area in the South Pole-Aitken (SPA) Basin on June 2.

The spacecraft finished its intelligent and rapid sampling work, and the samples were stowed in a container inside the ascender of the probe as planned, the CNSA said.

At some point, not yet specified, the ascender will dock with the orbiter-returner and transfer the samples to the returner, which after a period in orbit awaiting the right moment will then separate and head back to Earth.

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China releases movie taken by Chang’e-6 during its lunar descent

8:45 am

Chang'e-6 landing zone
Chang’e-6’s landing zone is indicated by the
red box, on the edge of Apollo Creater
(indicated by the wavy circle).

China’s state-run press yesterday released a short movie created from images taken by its Chang’e-6 lander during its descent to the lunar surface on the far side of the Moon this past weekend.

I have embedded that footage below. The final five frames however are very puzzling, in that they do not appear to show a smooth descent to a specific spot, but appear to jump about wildly. Moreover, the footage does not appear to show the actual landing itself, but appears to stop while the spacecraft is still above the ground.

It is possible that this footage is simply showing the spacecraft’s software searching for a good landing spot, combined with a decision in China not to release footage of the actual touchdown. It could also be that something has gone wrong, and they are stalling about saying so. This last possibility I think very unlikely, but it must be considered, based on the information available.
» Read more

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Chang’e-6’s lander successfully soft lands on far side of the Moon

8:47 pm

Chang'e-6 landing zone
Chang’e-6’s landing zone is indicated by the
red box, on the edge of Apollo Creater
(indicated by the wavy circle).

China today announced that today at 6:23 pm (Eastern) the lander of its Chang’e-6’s lunar orbiter successfully soft landed on far side of the Moon.

Teams will now begin initial checks of the lander’s systems and soon begin collecting samples. The lander will collect up to 2,000 grams of samples, using a scoop to grab surface regolith and a drill for subsurface material. Samples are expected to be sent into lunar orbit within around 48 hours. Chinese space authorities have yet to publish a timeline for the mission and its steps, however.

Once docked to the orbiter, the samples will get transferred to the return spacecraft, which will return to Earth and land in China, in the same manner as was done with its Chang’e-5 sample return mission in 2021. Unlike those earlier samples, which came from the Moon’s near side (where the Apollo and Soviet samples had come from), these new samples will be first obtained from the far side.

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Chang’e-6 to attempt landing on Moon’s far side on June 1st

9:42 am

Chang'e-6 landing zone

After spending almost a month in lunar orbit, the lander on China’s Chang’e-6 sample return mission will attempt a soft touchdown on Moon’s far side on June 1, 2024 at 8:00 pm (Eastern).

If successful, the lander will go through initial checks and setup. It will then begin drilling and scooping up materials from the surface. These samples, expected to weigh up to 2,000 grams, will be loaded into an ascent vehicle. The ascender will then launch the precious cargo back into lunar orbit for rendezvous and docking with the orbiter. Surface operations will last about 48 hours.

The map to the right indicates the landing zone by the red box, on the southern edge of Apollo Crater, indicated by the wavy white circle. The black circle marks the perimeter of South Aitken Basin, the largest impact basin on the Moon.

Once the ascender docks with the orbiter, the sample will be transferred into the sample return capsule, which will bring that sample back to Earth in late June.

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Chang’e-6 enters lunar orbit

9:42 am

Chang'e-6 landing zone

China’s Chang’e-6 sample return spacecraft successfully entered lunar orbit today, in preparation for its mission to land and bring back material from the the far side of the Moon. The landing zone is indicated by the red box on the map to the right, on the southern rim of Apollo Crater in the southern hemisphere. That crater is inside South Aitkin Basin, one the Moon’s largest impact basins.

The spacecraft will next adjust its orbit to prepare for sending its lander-ascender sections down to the surface. If the landing goes well, it will drill into the surface, place some material into the ascender section, which will then lift-off and dock with the orbiter-return section in orbit. The material will be transferred into the return section, which will separate and bring the material back to Earth, sometime in late June.

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China launches Chang’e-6 sample return mission to the far side of the Moon

9:17 am

Chang'e-6 landing zone

The new colonial movement: China today successfully launched its Chang’e-6 sample return mission to the far side of the Moon, its Long March 5 rocket lifting off from its coastal Wenchang spaceport. Unlike the Long March 5B, whose core stage reaches an unstable orbit and later crashes uncontrolled somewhere on Earth, the core stage of Long March 5 does not, and thus returns to Earth immediately, over the ocean.

The graphic from the right, released by China’s state-run press, shows the landing zone in red on the far side. The target is the southern rim area of Apollo Crater, marked by the uneven white outline. Apollo sits inside the South Aitken Basin, one of the Moon’s largest impact basins, 1,600 miles across, and roughly indicated by the black circle. The circle to the left of Apollo indicates Van Karman crater, where Chang’e-4 landed in 2019 with the Yutu-2 rover, both still operating.

The mission includes a lunar orbiter, a lander, an ascent vehicle, and an Earth sample return capsule. If all goes as planned, the samples will return to Earth in 53 days.

The leaders in the 2024 launch race:

45 SpaceX
18 China
6 Russia
5 Rocket Lab

American private enterprise still leads the world combined in successful launches, 52 to 30. SpaceX by itself still leads the rest of the world, including other American companies, 45 to 37.

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China launches communications orbiter towards the Moon

8:19 pm

Using its Long March 8 rocket lifting off from its coastal Wenchang spaceport, China today launched its second Quequiao communications satellite to the Moon, designed to relay data from its landers on the far side back to Earth.

The Queqiao 2, or Magpie Bridge 2, satellite was lifted atop a Long March 8 carrier rocket that blasted off at 8:31 am from a coastal launch pad at the Wenchang Space Launch Center in China’s southernmost island province of Hainan.

After a 24-minute flight, the satellite was released from the rocket and then entered into a lunar transfer trajectory. At the same time, the solar wings and communication antennas smoothly unfolded.

This satellite is in preparation for the May launch of China’s Chang’e-6 lunar mission to grab samples from the Moon’s far side and bring them back to Earth. In the meantime it will test its capabilities by relaying data from the Chang’e-4 lander and its Yutu-2 rover, still in operation on the far side after landing there in January 2018.

The leaders in the 2024 launch race:

27 SpaceX
11 China
3 Russia
3 Rocket Lab

American private enterprise still leads the rest of the world combined in successful launches 31 to 20, while SpaceX leads the entire world, including American companies, 27 to 24.

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China targets May 2024 for launch of its Chang’e-6 lunar sample return mission

9:10 am

The Moon's far side
The Moon’s far side. Click for interactive map.

China is now working to a May 2024 launch of its Chang’e-6 lunar sample return mission to bring back about four pounds of material from the far side of the Moon.

The map to the right, created from a global mosaic of Lunar Reconnaissance Orbiter (LRO) imagery, shows the planned location of Chang’e-6’s landing site, in Apollo Basin. The landing site of China’s previous mission to the Moon’s far side, Chang’e-4 and its rover Yutu, is also shown. Both are still operating there, since landing five years ago on January 2, 2019.

Chang’e-6’s mission will be similar to China’s previous lunar sample mission, Chang’e-5, which included a lander, ascender, orbiter, and returner. It launched in November 23, 2020, landed a week later, and within two days grabbed its samples and its ascender lifted off. The samples were back on Earth by December 16, 2020.

There are indications however that Chang’e-6 might spend more time on the surface before its ascender lifts off with samples.

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China targets 2024 for next lunar sample return mission

9:42 am

The new colonial movement: China’s next robotic lunar sample return mission, called Chang’e-6 and targeted for a 2024 launch, will also attempt to bring back the first samples from the far side of the Moon.

Hu Hao, chief engineer of the China Lunar Exploration and Space Engineering Center, announced in a statement released on China’s national space day in April this year that the Chang’e 6 probe, consisting of an orbiter, lander, lunar ascent vehicle and reentry capsule, will target the South Pole-Aitken (SPA) basin.The SPA basin is a colossal, ancient impact crater roughly 1,550 miles (2,500 kilometers) in diameter that covers almost a quarter of the moon’s far side. The impact basin, considered to be the oldest on the moon, holds vital clues about the history of the moon and the solar system, according to a new report.

The precise spot for landing has not been revealed. Since the basin is so large and covers the Moon’s south pole, the mission could land in that region where ice is thought to possibly exist in the permanently shadowed floors of some craters. Whether they would attempt a landing in one of those craters is presently unknown, though unlikely because of the technical challenge.

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International payloads will fly on China’s Chang’e-6 lunar sample return mission

9:34 am

The new colonial movement: China today announced that it is reserving space on its Chang’e-6 lunar sample return mission for international experiments.

The orbiter and lander of the Chang’e-6 mission will each reserve 10 kg for payloads, which will be selected from both domestic colleges, universities, private enterprises and foreign scientific research institutions, said Liu Jizhong, director of the China Lunar Exploration and Space Engineering Center of the CNSA, at a press conference.

I suspect that the majority of these experiments will be Chinese, but I am also sure that China will get at least one international partner.

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