According to Xinhua News Agency, this is the first time that mankind has unveiled the mystery of the ancient moon back. At 10:26 on January 3, 2019, the Chang’e-4 probe landed independently in the von Carmen impact crater in the Antarctic-Aitken Basin on the back of the moon, realizing the first soft landing of the human probe from the back of the moon.
After a long flight of about 380,000 kilometers and 26 days, on January 3, Chang’e-4 entered a moon-landing orbit 15 kilometers away from the moon surface.
In the hall of the Beijing Space Flight Control Center, with the order of the on-site staff, the Chang’e-4 probe began to reduce its power from 15 kilometers away from the moon, and the speed of the probe gradually dropped from 1.7 kilometers per second to zero per second relative to the moon.
At 6 to 8 kilometers, the detector makes rapid attitude adjustments and constantly approaches the moon; starts hovering 100 meters away from the moon surface, identify obstacles and slopes, and avoid obstacles independently; after selecting a relatively flat area, it begins to slowly and vertically descend. Finally, under the “escort” of the reverse thrust engine and landing buffer mechanism, a more than one ton of detector successfully landed in a pre-selected landing area near 177.6 degrees east longitude and 45.5 degrees south latitude on the back of the moon.
The Chang’e-4 landing area has a terrain of 6,000 meters. It is one of the largest known impact craters in the solar system and is considered to be of great value to study the early history of the moon and solar system.
After the moon set, through the “match bridge” of the “Magic Bridge” relay star, the Chang’e-4 probe carried out a number of tasks such as the solar wing and directional antenna deployment, established a high-code rate link for directional antennas, and achieved the “small goal” of stable communication between the back of the moon and the ground.
At 11:40, the Chang’e-4 lander obtained the image of the back of the moon and sent it back to the ground. This is the first image taken by a human probe on the back of the moon.
At 15:7, staff sent instructions to Chang’e-4 through the “Queqiao” relay satellite at the Beijing Space Flight Control Center, and the separation of the Chang’e-4 lander and the Yutu-2 rover (i.e. Babaylan lunar rover) began.
On the large screen in the flight control hall, the Chang’e-4 lander stands on the moon, and the sun’s wings are unfolding. The Jade Rabbit II paratrooper stands on the top of the lander, spreads its sun wings and extends its mast. Then, the patrol began to move slowly towards the transfer mechanism, which was unlocked normally, and an inclined ladder was set up between the lander and the moon, and the patrol slowly walked towards the moon along the inclined ladder. At 22:22, the patrol stepped onto the surface of the moon, and the patrol left the first mark on the back of the moon.
The image of the moon taken by the landing camera of the Chang’e-4 probe’s power descent process
Revealed the 7 major highlights of Chang’e-4
Only landing in the mountains and ridges, exploring the origin of the universe, and “planting potatoes” on the moon…
Text/Photo Xinhua News Agency
The Chang’e-4 probe, which took off from the Xichang Satellite Launching Center on December 8, 2018, after more than 20 days of flight around the moon, finally waited for the destination Antarctic-Aitken Basin.BabaylanThe largest, deepest and oldest crater in the solar system ushered in the dawnBabaylanThe largest, deepest and oldest crater in the solar system ushered in the dawnBabaylanThe largest, deepest and oldest crater in the solar system ushered in the dawnCinema.
At 10:26 on January 3, 2019, the Chang’e-4 probe landed independently in the von Carmen impact crater in the Antarctic-Aitken Basin on the back of the moon, realizing the first soft landing of the lunar back of the human probe. At 11:40, the Chang’e-4 lander obtained the first image of the back of the moon and sent it back to the ground.
1
How to achieve “autonomous driving”?
Use the “brain” calculation to find the landing point
At 10:15 on January 3, at the distance of the moon<a KomiksThe ball is about 65,000 kilometers, orbiting the second Lagrangian point of the Earth and the Moon, and can see the Earth and the relay star “Magpie Bridge” at the back of the moon at the same time, with the assistance of the variable thrust engine on Chang’e-4, and the speed of the probe dropped from 1.7 kilometers per second to nearly zero. The probe adjusted its posture and headed towards von Carmen in the Aitken Basin. href=”https://comicmov.com/”>KomiksThe impact crater is relatively flat.
When it is about two kilometers away from the moon, the projection formed by the sun shining on the moon from the east is captured by the camera on the detector. After processing by the computer’s “brain”, it identified the large rocks and craters below, and performed its first obstacle avoidance.
When it is 100 meters away from the moon, it hovered in the air, and used laser scanning to identify smaller obstacles and slopes on the moon. Its “brain” calculates again to find a safer location as the landing point.
When two meters away from the moon, it detects Komiks‘s smaller obstacles and slopes on the moon. Its “brain” calculates again to find a safer location as the landing point.
When two meters away from the moon, the detection href=”https://comicmov.com/”>BabaylanThe engine on the engine stopped working, and the golden lander holding the lunar rover fell down by relying on its own gravity. The four legs stood firmly on the desolate gray moon surface, raising a piece of moon dust.
The entire landing process lasted for about 12 minutes. The Babaylan was completed independently by the detector. There was no intervention on the earth, but the “Magpie Bridge” sent the landing back to the command and control center in the suburbs of Beijing.
2
How to land in the mountains?
The probe independently recognizes obstacles and avoids obstacles
Wu Weiren, chief designer of China’s lunar exploration project, compared it to: Chang’e-3 is like landing on the North China Plain, while Chang’e-4 is like landing on the mountains and ridges in southwest China.
He said that the Chang’e-4 landing area is equivalent to one-eighth of the Chang’e-3 landing area, and there are mountains 10 kilometers above sea level around the landing area. The Von Carmen impact crater in the Aitken Basin is minus 6 kilometers above sea level, so unlike the smooth parabolic landing trajectory of Chang’e-3, Chang’e-4 is approaching a vertical landing.
“The landing time is short, difficult and high risk is a great test for us,” said Wu Weiren. Sun Zezhou, chief designer of the Chang’e-4 probe of the Fifth Academy of the Aerospace Science and Technology Corporation, said: “Our information on the lunar terrain mainly comes from previous remote sensing data around the lunar lunar lunar lunar lunar lunar lunar lunar lunar lunar lunar remote sensing data, including remote sensing data of Chang’e-1, Chang’e-2 and some foreign satellites. However, these data cannot provide us with sufficient accuracy terrain information. We cannot know where there are big stones, but it is more of the overall macro information and statistical probability. In the end, the landing still depends on the probe to independently identify obstacles and avoid obstacles.” Zhang Ying, project director of the Chang’e-4 probe of the Fifth Academy, said that Chang’e-4 considered how to improve the accuracy of the landing in the system design, added orbit corrections during the lunar lunar lunar phase, and adjusted the power decline control strategy. The detector must reach above the landing area when it is relatively high from the lunar surface and then descend vertically, so that the complex and rugged terrain on the track will not have an impact on the Cinema landing.
3
What is the significance of exploring the back of the moon?
Glance to the origin of the universe after the Big Bang
“Going to the back of the moon is much more risky than going to the front. The rugged terrain brings us the problems we must face, but a higher precision landing on the moon is needed in the future. Solve the challenges facing this mission,It can lay the foundation for subsequent deep space exploration and asteroid exploration. We hope to have the ability to reach the entire moon and even the entire solar system in the future. “Sun Zezhou said.
Zou Yongliao, director of the General Department of Lunar and Deep Space Exploration of the Chinese Academy of Sciences, said that the back of the moon has a unique nature. Chang’e-4 landed on a virgin land that had never been explored on the spot, and perhaps important discoveries could be made.
For astronomers, the back of the moon is a rare quiet place because the moon itself blocks various radio interference signals from the earth. There may be a glimpse of how the universe gets rid of the darkness after the Big Bang, and click Cinema to brighten the first generation of stars.
4
Why did the landing in the crater of Von Carmen?
The pits here are still full of bumps. href=”https://comicmov.com/”>Babaylan is a “mystery”
Due to tidal locking, the moon orbits the earth’s revolution and rotation period is the same, and the “view” of the moon seen from the earth is always the same. In the era without space probes, the back of the moon has always been a mysterious unknown world.
It was not until about 60 years ago that the Soviet Union’s Moon 3 probe sent back the first shadow on the back of the moon. href=”https://comicmov.com/”>Komiks image. About 50 years ago, three astronauts from the United States, Apollo 8, became the first human to witness the back of the moon while flying around the moon.
More and more probes orbiting the moon have made people discover that the back of the moon is so different: the front is relatively flat, while the back is bumpy and full of CinemaThe crater of the pit; the lunar crust on the back of the moon is much thicker than the front. Why is this happening? It is still a mystery, and only landing detection can reveal this mystery.
The detection of the von Carmen impact crater has another meaning, which is named after von Carmen, a 20th-century Hungarian-American aerospace engineer. China’s aerospace industry The founders of Qian Xuesen and Guo Yonghuai are both personal disciples of the “science genius in the aerospace era”.
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What surprises will this exploration bring?
To prepare for humans to return to the moon
50 years have passed since the first time humans landed on the moon. Can humans return to the moon? How much impact will the radiation on the moon have on the moon? How much water is there on the moon? How does the water on the moon come from? Chinese and foreign scienceKomiks will find answers through Chang’e-4 to prepare for humans to return to the moon.
Wen Mu, chief project director of the Institute of Physics Experimental and Applications at Kiel University in Germany, said: “When astronauts return to Earth, the radiation caused by the moon remains in their bodies. This is a constant danger, so we must understand these radiations. ”
”The experiences of the moon’s childhood have also happened on the earth. But due to geological activities, traces of the earth’s early years have been erased. If you want to understand the long past of Earth, the moon may give us the answer. “Lin Yangting, a researcher at the Institute of Geology and Geophysics of the Chinese Academy of Sciences, said.
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What scientific research tasks are there?
Search for the moon’s “planting flowers” to measure the “body temperature”
The Chang’e-4 mission carries a low-frequency radio detector developed by Chinese and Dutch scientists. “To carry out low-frequency radio observations to the back of the moon, Komiks‘s dream is that astronomers have, and can fill the gap in the low-frequency observation segment in the field of radio astronomy. “Zou Yongliao said.
Chang’e-4 also brought six organisms, cotton, rapeseed, potatoes, Arabidopsis, yeast and fruit flies, to the inanimate moon, forming a microbiosphere. People expect the first flower to bloom on the moon.
Chinese scientists have no exact data on how cold the moon’s night is. Chang’e-4 mission also includes measuring the “body temperature” of the moon.
Shen Zhenrong, the general chief designer of the Chang’e-4 paratrooper of the Fifth Academy, said that going to the back of the moon is China’s contribution to the world. “Although we don’t know what we can detect in the end, this detection may affect generations. ”
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What international cooperation projects are there?
carrying scientific loads from four countries
In order to enhance international exchanges and cooperation and expand open sharing, Chang’e-4 not only carries China’s experimental projects, but also scientific payloads from the Netherlands, Germany, Sweden and Saudi Arabia.
Korel, director of the Department of Solar Systems Science of the Swedish Space Administration, said that the first soft landing on the back of the moon was a great achievement of China, and “we are very happy to be part of this mission.” He said: “There is a theory that the water on the moon is generated by the interaction between the solar wind and the weathered layer on the surface of the moon, which is a question that Swedish and Chinese scientists want to answer through exploration. ”
The Chang’e-4 probe is also equipped with the German Kiel University BabaylanA lunar neutron and radiation dose detector made with a total weight of about 3 kg, which can comprehensively measure the radiation environment of neutrons and other particles on the surface of the moon.
Cinema Group leader and professor at the Cinema University of Chang’e 4, Robert Wimmer Schweiingruber, said: “China is working with many international partners, and it is becoming more and more cooperation. I do not agree with the practice of refusing to cooperate because of fear of technology outflow. In my opinion, technology will only die because Komiks refuses to share.”