China Lunar Exploration Project:
Six battles and six victories, "Chang'e" writes a new chapter in mankind's lunar exploration
Previously, many of the things done by China's lunar exploration project were done by others, and we are learning from other people's experiences.
Now, we can also come up with something and let others do something with us.
——Ye Peijian, academician of the Chinese Academy of Sciences, technical consultant of the Fifth Academy of China Aerospace Science and Technology Corporation, chief designer and commander of the Chang'e-1 satellite
◎Reporter He Liang and Fu Yifei
Go back with the moon, walk in dreams.
In the early morning of December 17, 2020, the Chang'e-5 returner carried a lunar sample, reentered and returned using a semi-ballistic jump method, and landed safely in the planned area of Siziwang Banner, Inner Mongolia.
As the Chang'e-5 returner successfully completed the lunar "digging" mission and returned home with the moon's "local products", the flight control site of the Chang'e-5 mission of the Beijing Aerospace Flight Control Center immediately became a sea of joy, and everyone cheered, Hug and congratulate each other.
The successful implementation of the Chang'e 5 mission marked the completion of the three-step plan for the "circumnavigation, landing and return" of my country's lunar exploration project as scheduled.
Take a road to break through from scratch
Twenty years ago, my country initiated the demonstration of the lunar exploration project, and a road to breakthrough has been paved since then.
At the age of 55, Ye Peijian was one of the first core researchers.
At the beginning of 2004, China's lunar exploration project was approved and officially entered the implementation stage.
The project was named the lunar exploration project, and it was divided into three phases of "circumnavigation, landing, and return". Ye Peijian served as the chief designer and commander of the Chang'e-1 satellite.
Now, China has not only been able to go to the moon, but it has also achieved a landing on the back of the moon and a sample return on the moon.
While in charge of the Chang'e-1 mission, "how to ensure that the Chang'e-1 accurately enters the orbit around the moon" worries Ye Peijian.
At that time, there were very few people doing orbital research in China, and they couldn't experiment.
A severe test lies ahead: which track is feasible?
Ye Peijian found Nanjing University, National University of Defense Technology, and Chinese Academy of Sciences, and gave the purpose, ideas, and all the conditions for going to the moon to three units, and asked them to perform calculations "back-to-back". The final three calculations were the same.
Ye Peijian said, this track will do.
Afterwards, the comrade doing the track design was a little unhappy and said, "Ye Peijian, you don't trust me."
But Ye Peijian's response is that this is not a question of trusting or distrusting a person, but rather that there is no room for mistakes in scientific research, and you must be more careful.
You must know that at that time the United States and the Soviet Union were the two countries with the most powerful lunar exploration technology in the world. In contrast, China's lunar exploration project was groping and advancing from scratch in many blank areas.
China does not have lunar exploration satellites. Chinese scientists have tried to take the effective knowledge of earth satellites, coupled with the latest achievements in electronic technology, radio technology, and material technology, to organize teams to tackle key problems in new technologies.
At that time, foreign lunar satellites all had ultraviolet sensors, but China did not.
The lunar exploration project organized a doctoral team to start from the beginning. After several years of hard work, the UV sensor was developed. In Ye Peijian's words, "only with this determination can we innovate."
Before Chang'e-1, China's ground-based measurement and control antenna was up to 12 meters, while the smallest antenna for lunar exploration in the world was 38 meters. How to make up for it?
There is only one way, and that is to make the various electronic equipment on the satellite reach the highest level of internationally recognized theoretical values!
The Chinese Lunar Exploration Project has done it.
In October 2007, China's first lunar exploration satellite, Chang'e-1, was successfully launched in Xichang. After 8 changes of orbit, Chang'e-1 entered working orbit and sent back lunar images. China Aerospace is flying. A solid first step has been taken on the way to the moon to explore deep space.
From then on, it can’t be said that the Chinese will only follow suit
In the lunar exploration project, the single-numbered star is the primary star and the double-numbered star is the backup star.
After the successful success of the Chang'e-1 mission, there is a view that it is not advisable to continue to launch the Chang'e-2 out of economy, but Ye Peijian strives for reasons.
"There is still a lot of work to be done for the Chinese lunar exploration project to go on. The Chang'e-1 has already been completed. What's wrong with spending some money to get more scientific results and more engineering experience?" Ye Peijian Many scientists changed their minds due to his explanation, and his persistence also made Chang'e-2, the backup star of Chang'e 1, the pilot star of the second phase of the lunar exploration project.
Facts have proved that Chang'e-2, which was launched on the National Day in 2010, not only made further progress in the results of lunar exploration, but also laid the foundation for the follow-up mission to the moon, and successfully carried out a number of extended experiments.
It completed the detection of the Sun-Earth Lagrangian L2 point and the overflight detection of the Tutatis asteroid, and obtained precious scientific data; it finally flew to a distance of 100 million kilometers, and also verified my country's deep space detection capabilities. .
Three years later, in December 2013, the Chang'e-3 probe successfully completed its mission to the moon. Its backup star, Chang'e-4, was no longer in disputes over whether to launch, but there were disagreements on what mission it would perform.
At that time, some people believed that Chang'e 4 did not need to take risks, and that it would be more secure to land on the front of the moon, while Ye Peijian advocated that Chang'e 4 should take the step that humans have not yet taken-landing on the back of the moon.
Before Chang'e-4, the back of the moon was a blank in the history of human landing on the lunar exploration.
The difficulty of landing on the back of the moon is that the moon is always facing the earth, and its back can not establish communication with the earth. When the Chinese lunar exploration project finally decides to challenge the back of the moon, it must first be in the inter-lunar Lagrangian behind the moon. At L2, a communication relay satellite is set up. The name of this satellite is "Queqiao".
In May 2018, the "Magpie Bridge" was successfully launched.
Seven months later, the Chang'e-4 lunar probe became the first human probe to land on the back of the moon.
Because of the landing on the back of the moon, China has mastered the technology and capabilities of lunar relay satellites. If the relay satellite has a long lifespan, it is likely to provide services to the world. This is what Ye Peijian attaches great importance to.
"Before, many of the things that China's lunar exploration project did were done by others, and we learned from others' experience. Now, we can also come up with something and let others do something with us." Ye Peijian said. .
Regarding the success of the Chang'e-4 mission, an expert from the National Aeronautics and Space Administration lamented: "From now on, we can't say that the Chinese will only follow suit, and they have done things that we haven't done before."
Tens of thousands of scientific and technological workers jointly support "Chang'e" to fly to the sky
At the beginning of the Chang'e 5 mission, during a probe plan review, some experts raised objections: “There are too many mechanisms and too many links. Every action is a bottleneck risk point. One link will not work. Nothing works. The mission is too risky."
The opinions of experts made Hu Hao, the chief designer of the third phase of the National Space Administration's lunar exploration project, feel a lot of pressure.
He is very clear that China Aerospace has never had such a complicated mission before, and this time it will go through 11 major stages and key links, which are interlocking and startling.
Zhang Yuhua, the person in charge of the Lunar Exploration Project at the Eighth Academy of China Aerospace Science and Technology Corporation, has the same feeling.
The team she leads is responsible for the development of the Chang'e-5 orbiter, which is the spacecraft that she has experienced the longest time and the most arduous development in multiple lunar exploration missions.
"The Chang'e-5 probe is composed of four parts. The state of multi-device division of labor and cooperation has created a process of continuous separation and combination, separation and recombination of the probe in space, which is unique in my country's spacecraft." She said .
At 4:30 on November 24, 2020, the tail flames of the Long March 5 Yaowu carrier rocket burst out and lifted Chang'e 5 toward the moon with all its strength.
23 days later, in the early morning of December 17, after surpassing the lunar surface landing, automatic sampling, lunar takeoff, lunar orbital rendezvous and docking, and reentry and return, after many difficulties, the Chang'e-5 returner, which has undergone many tests, carried lunar samples. Return to the ground successfully.
23 days is a test of the 10-year study of Chang'e-5.
The three steps of "circumnavigating, descending and returning" to the lunar exploration can be successfully completed. For the scientists of the Chinese lunar exploration project, it is time to hand in the examination papers.
Previously, due to various reasons, the launch time of Chang'e 5 has undergone many changes. After the probe was developed, it also experienced a three-year storage wait.
After the success of the Chang'e 5 mission, General Secretary Xi Jinping pointed out in his congratulatory message: The Chang'e 5 mission, as my country's most complex aerospace system project with the largest technological span, has realized the return of samples from my country's extraterrestrial celestial bodies for the first time.
This is another major achievement made by leveraging the advantages of the new nationwide system to overcome difficulties.
Wu Yanhua, deputy director of the National Space Administration and deputy commander-in-chief of the lunar exploration project, said that since the establishment of the lunar exploration project in 2004, China’s lunar exploration project has "drawn a blueprint to the end", "one-stop" tackling key problems, "a game of chess," coordinated advancement, and "integration." Iterative improvement has achieved "six battles and six victories".
The lunar exploration project brought together thousands of units and tens of thousands of scientific and technological workers across the country, including Hong Kong and Macao. Every breakthrough in technology and every step of the project is the result of unity and cooperation.
Whether it is a gray-haired academician expert, a science and technology leader who has grown up with the lunar exploration project, or a fledgling scientific research "recruit", it is their hands that have extended the "Chang'e" to successfully fly into the sky time and time again.
Provide Chinese solutions for the peaceful use of space by mankind
The success of the Chang'e 5 mission not only inspires the Chinese people, but also the head of the tracking station network of the European Space Agency (ESA) ground control center tracking station network. He also expressed to the media that he is very happy to witness the lunar exploration made by Chang'e 5. Significant achievements, I believe that China-EU cooperation in the field of aerospace can go further.
During the launch and return phase of Chang'e 5, the ESA Ground Control Center in Darmstadt, Germany, coordinated its tracking station network with the ground stations of the cooperating units, and tracked Chang'e 5 by receiving telemetry signals and combined relevant data. Passed to the Beijing Flight Control Center, this series of operations was led by the Billig team.
As a frontline person providing technical support, Billige said: "This mission has achieved great success. No one has done it for so many years. Completing this mission is a big step forward."
According to Wu Yanhua, in the implementation of the Chang'e-5 mission, my country has carried out coordinated cooperation in the field of measurement and control with ESA, Argentina, Namibia, and Pakistan.
The Chinese lunar exploration project has always adhered to the basic principles of peaceful use and win-win cooperation, actively opening up some resources, helping to carry scientific instruments and equipment from many countries, and opening the valuable raw detection data obtained to the world, which fully reflects Responsibility and mind of a big country.
Wu Yanhua said that for the planned Chang'e 7 and 8 missions, my country is also ready to use this as an opportunity to cooperate with relevant countries and international organizations to jointly demonstrate the basic capabilities of the initial construction of lunar research stations or verify core technologies.
In the future, China's planetary exploration program will move toward the moon, Mars and even more distant deep space. "Win-win cooperation" will always be the Chinese solution provided by China Aerospace for the peaceful use of space for mankind.