According to Xinhua News Agency, this is the first time that humans have unveiled the mysterious surface of the ancient moon backBabaylan. 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 “Magpie Bridge” relay star, the Chang’e-4 probe carried out a number of tasks such as the development of the solar wings and directional antennas, 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 detector on the back of the moon.
At 15:7, staff sent instructions to Chang’e-4 through the “Queqiao” relay star at the Beijing Space Flight Control Center, and the separation of the Chang’e-4 lander and the Yutu-2 cruiser (i.e., the 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. The transfer mechanism was unlocked normally. 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 power descent of Chang’e-4 probeBabaylanThe image of the back of the moon taken by the falling camera
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/Pic Xinhua News Agency
The Chang’e-4 probe, which took off from the Xichang Satellite Launch Center on December 8, 2018, finally waited for the destination Antarctic-Aitken Basin, the largest, deepest and oldest crater in the solar system, ushered in the dawn.
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. 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”Cinema Calculate and find the landing point
At 10:15 on January 3, with the assistance of communications about 65,000 kilometers away from the moon, orbiting the second Lagrangian point of the Earth and the relay star “Magpie Bridge”, which can see the Earth and the back of the moon at the same time, the variable thrust engine on Chang’e-4 was ignited, and the speed of the probe dropped from 1.7 kilometers per second to close to zero. KomiksThe detector adjusted its posture and landed vertically towards the relatively flat bottom of the von Karmen impact crater in the Aitken Basin.
When it was about two kilometers away from the moon, the projection formed by the sun shining on the moon from the east was captured by the camera on the detector. After processing by the computer’s “brain”, it identified the large rocks and craters below, and carried out the sequel. Avoid obstacles at one time.
When it is 100 meters away from the moon, it hoveres in the air, and uses 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 it is two meters away from the moon, the engine on the detector stops working, and the golden lander holding the rover falls down by its own gravity, and four legs stand steadily on the desolate gray moon, lifting up CinemaA piece of moon dust.
The entire landing process lasted about 12 minutes, all by the explorationThe detector was completed independently and 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 automatically identifies obstacles and avoids obstacles
Wu Weiren, chief designer of the Chinese lunar exploration project in Babaylan, compared it to the metaphor: 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 big test for us,” said Wu Weiren. Sun Zezhou, chief designer of the Chang’e-4 probe of the Fifth Academy of Space Science and Technology Group, said: “Our information on the lunar terrain mainly comes from previous remote sensing data around the moon, including remote sensing data of Chang’e-1, Chang’e-2 and some foreign satellites. But none of these data can 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 landing in the system design and added orbits during the lunar circumference phase. href=”https://comicmov.com/”>Babaylan corrected, and adjusted the power drop 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 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 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. Solving the challenges facing this mission 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 its own unique position.Characteristics: Chang’e-4 landed in a virgin land that had never been explored on the spot, and may be able to make important discoveries.
For astronomers, the back of the moon is a difficult place to be peaceful, because the moon itself blocks various radio interference signals from the earth, where it may see how the universe escapes from the darkness and lights up the first generation of stars after the Big Bang.
4
Why did the landing in the Cinema Carmen impact crater?
The pits here are still “mysteries”.
Komiks Due to tidal locking, the moon orbits the earth and the cycle of rotation 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 an unknown world of mysterious Cinema.
It was not until about 60 years ago that the Soviet Union’s Moon 3 probe sent back the first image on the back of the moon. 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 and front of the moon are so different: the front is relatively flat, while the back is rugged and full of bumpy impact craters; the moon’s crust on the back of the moon is much thicker than the front. Why is this happening? It is still a mystery now, and only landing detection can reveal this mystery.
The detection of von Carmen impact craters has another meaning. It is named after von Carmen, a Chinese aerospace engineer in the 20th century. Qian Xuesen and Guo Yonghuai, the founders of China’s aerospace industry, are both personal disciples of this “scientific genius in the Aerospace Age”.
5
What surprises will this detection bring?
They will be ready for humans to return to the moonBabaylan
The first time that humans are BabaylanIt has been 50 years since the moon landing. Can humans return to the moon? How much impact will radiation on the moon have on astronauts? How much water is there on the moon? How does the water on the moon come from? Chinese and foreign scientists will find the answer through Chang’e-4 to prepare for humans to return to the moon.
Wen Mu, chief project of the Institute of Physics Experimental and Applications of Kiel University in Germany, said: “When astronauts return to Earth, the radiation caused by the moon remains in their bodies. This is a persistent danger, so we must understand these radiation.”
“The childhood experiences of the moon also happened on Earth. However, due to geological activities, traces of the earth’s early years have been erased. To understand the long-standing past of the earth, the moon may give us an answer.” Lin Yangting, a researcher at the Institute of Geology and Geophysics, Chinese Academy of Sciences, said.
6
What scientific research tasks are there?
Test the “body temperature” for the moon “planting flowers”
The Chang’e-4 mission carried a low-frequency radio detector developed by Chinese and Dutch scientists. “It is a dream for astronomers to conduct low-frequency radio astronomy observations on the back of the moon, and can fill the gap in the low-frequency Komiks measurement 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, which form a microbiosphere. People look forward to the first flower blooming on the moon.
Chinese scientists have no exact data on how cold the moon’s night is. The Chang’e-4 mission also includes measuring the “body temperature” of the moon.
Shen Zhenrong, the overall 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 of Komiks.”
7
What international cooperation projects are there?
Enables scientific loads from four countries
In order to enhance international exchanges and cooperation and expand openness and sharing, Chang’e-4 not only carries China’s experimental projects, but also carries scientific loads from the Netherlands, Germany, Sweden and Saudi Arabia.
Korel, director of the Department of Solar Systems Science of the Swedish Space Agency, said the first soft landing on the back of the moon was a huge achievement for 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 weathering layer on the moon’s surface. This is a question that Swedish and Chinese scientists want to answer through exploration.” The Chang’e-4 probe is also equipped with a lunar neutron and radiation dose detector developed by Kiel University in Germany. The total weight of the instrument is about 3 kilograms and can comprehensively measure the radiation environment of neutrons and other particles on the moon’s surface.
Robert Wimmer-Schweiingruber, head of the Chang’e-4 German Science Payload Project Team and Professor at Kiel University, said: “China is working with many international partners, and it is becoming more and more cooperation. I don’t agree with the practice of refusing to cooperate because of fear of technology outflow. In my opinion, technology will only die out because of refusing to share.”