Lander and astronauts to act separately? See what else China's preliminary plan for manned lunar landing says

China has announced a preliminary plan for a manned lunar landing, planning to send astronauts to the moon to conduct scientific exploration by 2030, and then explore the construction of a lunar scientific research station. What are the characteristics of China's manned lunar landing plan?

Written by Li Peng, Photo and text edited by Chen Yongjie

New Media Editor/Zhang Hongwei

Audit experts:

Pang Zhihao (Chief Scientific Communication Expert of National Space Exploration Technology)

China will send astronauts to the moon before 2030! Recently, there is big news about China's lunar exploration project! Attention! It's about astronauts, not probes and lunar rovers!

"Our country plans to achieve manned lunar landing and conduct scientific exploration before 2030. After that, we will explore the construction of a lunar scientific research test station and carry out systematic and continuous lunar exploration and related technical tests and verifications." Not long ago, at the 9th China (International) Commercial Space Summit held in Wuhan, Zhang Hailian, deputy chief designer of the China Manned Space Engineering Office, introduced the preliminary plan for the lunar landing.

It is understood that my country's initial plan for manned lunar landing is to use two launch vehicles to send the lunar lander and manned spacecraft to the Earth-Moon transfer orbit respectively, the spacecraft and lander will rendezvous and dock in the lunar orbit, and the astronauts will enter the lunar lander from the spacecraft. Afterwards, the lunar lander will descend and land in a predetermined area on the moon, and the astronauts will go to the moon to conduct scientific investigations and sample collection. After completing the established tasks, the astronauts will take the lander to rise to the lunar orbit to rendezvous and dock with the spacecraft, and return to Earth on the spacecraft with the samples. It is reported that we will send three astronauts at a time, two of whom will land on the lunar surface to conduct scientific research.

▲Rendering of China's manned lunar mission (Photo source: China Manned Space Engineering Office)

Why launch two rockets? What are the advantages and disadvantages of this solution? What other technical difficulties need to be overcome?

If one rocket is not enough, use two.

Once the plan was released, many people were curious, why do we need to use two launch vehicles? Wouldn't it be better to launch once? According to relevant experts, this is closely related to my country's current rocket design and manufacturing capabilities. It is reported that my country's new generation of Long March 10 manned carrier rocket, which is preparing to implement the manned lunar landing project, has a three-and-a-half-stage configuration, a body diameter of 5 meters, a height of about 92 meters, a take-off mass of about 2,187 tons, and a take-off thrust of about 2,678 tons. Its low-Earth orbit carrying capacity is 70 tons, and its Earth-Moon transfer orbit carrying capacity is about 27 tons. However, such a carrying capacity cannot deliver a new generation of manned spacecraft and a lunar lander to the lunar orbit at one time. Therefore, my country adopted a two-launch plan, first launching a lunar lander weighing about 26 tons, and then launching a manned spacecraft weighing more than 20 tons.

▲ A model of the Long March 10 carrier rocket on display at the "Dreaming of the Universe - Thirty Years of Achievements in China's Manned Space Program" exhibition (Photo source: Visual China)

Researcher Pang Zhihao, the chief scientific communication expert of national space exploration technology, said that the development of heavy-load carrier rockets is difficult, the cycle is long, and the cost is also high. The use of two carrier rockets reduces the requirements for the rocket's carrying capacity. my country does not have to wait until the heavy-load carrier rocket is developed before implementing manned lunar landings, so that my country can realize the dream of manned lunar landings ahead of schedule. In addition, my country's new generation of manned spacecraft that can carry three astronauts consists of an escape tower, a return capsule, and a service module. It adopts a modular design to meet the needs of near-earth and deep space missions. The lunar lander consists of a lunar module and a propulsion module, which can deliver two astronauts to the lunar surface (another astronaut staying in the manned spacecraft in the lunar orbit provides security services for the two lunar landers). The manned lunar rover weighs about 200 kilograms and can carry two astronauts. In order to ensure the safety of astronauts landing on the moon, new lunar suits must also be developed. The lunar suit that my country is developing adopts a semi-rigid configuration, with a single working time of no less than 8 hours. It has the capabilities to support the astronauts' extravehicular activities on the moon, including working, walking, climbing, squatting, driving, and human-machine collaboration.

Begins solicitation of research payloads for manned lunar landing

Today, the implementation of manned lunar landing and the need to conduct as many scientific investigations and research as possible are important goals of the action. In order to promote the rapid follow-up of relevant research institutions in my country in this regard, on July 17, the China Manned Space Engineering Office issued the "Announcement on the Collection of Lunar Surface Scientific Payload Plans for Manned Lunar Exploration Project". The announcement stated that in order to make full use of flight mission resources and promote lunar exploration and scientific research, it is planned to carry scientific payloads with the lunar lander and carry out relevant scientific exploration activities on the lunar surface. Scientific payload plans are now being collected. The scope of this collection includes scientific research institutions, colleges and universities, and high-tech enterprises with independent legal person status. In other words, as long as you are interested and capable, you can participate in the drama of China's manned lunar landing project.

▲China has achieved the unmanned lunar missions of Chang'e 3 and 4 (Photo source: Visual China)

It is understood that the payload includes three types: scientific payload for unmanned lunar mission, scientific payload for manned lunar mission and special payload for lunar drilling. The basic requirements for the payload are: facing the frontier of lunar scientific research, with strong foresight and innovation. The reference directions are lunar geology and lunar physics, observation and physical research, space life sciences, as well as deep lunar drilling and lunar resource utilization. How will these payloads work? It is reported that in the unmanned lunar missions of Chang'e 3 and 4, the lunar rover was released and separated by the lunar lander and worked independently. In manned lunar missions, it can be deployed and carried out with the participation of astronauts. Among them, the lunar rover used by astronauts will be a focus of attention, because on the surface of the moon, astronauts ride in the lunar rover for scientific investigation, which can greatly expand the scope of activities and improve work efficiency. At present, the China Manned Space Engineering Office is soliciting the development plan of the manned lunar rover from the whole society. By then, Chinese astronauts will drive the manned lunar rover around and explore on the surface of the moon. Such a scene must be quite cool!

How is it different from the new U.S. manned lunar landing plan?

The United States' latest manned lunar landing plan is called the Artemis Program, a manned space program funded by the US government. The original goal was to send two astronauts, one man and one woman, to the moon and return them by 2024.

Some people call this return to the moon "Apollo 2.0". Due to some engineering projects not going well, the time has been postponed. It was first said to be postponed to 2025, and from the latest signs, its launch time will be postponed again.

▲ The US Artemis program aims to send two astronauts, one man and one woman, to the moon and back by 2024 (Image source/NASA)

NASA plans to carry out two lunar orbits, the first without astronauts, the second with astronauts, and the third with astronauts on the "Starship" developed by SpaceX. According to the plan, they will land on the moon near the south pole of the moon.

Unlike China, the United States still uses a single rocket launch method, which they call the "Space Launch System". Compared with the "Saturn 5" rocket used in the Apollo moon mission, the "Space Launch System" is shorter, narrower, but more powerful. The rocket is 98 meters high and has a thrust of 4,100 tons, surpassing the "Saturn 5". Its low-orbit carrying capacity can reach 70 tons to 130 tons, making it the super-heavy carrier rocket with the largest carrying capacity in service.

It is reported that China's manned lunar landing method is different from that of the United States' previous Apollo manned lunar landing. Their lunar module landed on the moon together with the ascent stage and descent stage, while we adopted a plan to slow down the propulsion module in order to reduce the fuel consumption of the lunar module. We separated the propulsion module when the lander was about to reach the moon, and then let the lunar module land on the moon.

▲Schematic diagram of the lander of China's manned lunar landing project, including the lunar module and the propulsion module (Photo source: Visual China)

Both the Chinese and American lunar landing plans use their own relatively mature technologies and plans, and both have their merits. However, Pang Zhihao said that my country's manned lunar landing plan uses two launch vehicles for launch, and the lunar landing method is also different from that of the United States, which is an innovation based on my country's national conditions.

There is currently no very detailed plan for what changes will be made to the landing method of America's new manned lunar astronauts.

China gets a "return ticket" from the moon

So far, only the United States has achieved multiple manned lunar landings in the late 1960s and early 1970s. Since then, there has been no new manned lunar landing case in the world.

Between 1969 and December 1972, the United States carried out seven manned lunar missions, six of which were successful, sending a total of 12 astronauts to the moon.

In this competition, the United States eventually won over the Soviet Union and won great honor. To this day, the American flag planted on the Sea of ​​Tranquility on the moon has become the only symbol of human conquest of the moon, which means that the United States is the only country to have successfully implemented a manned lunar landing.

The overall goal of the lunar landing phase of China's manned lunar exploration project is to achieve the first Chinese landing on the moon before 2030, conduct lunar scientific expeditions and related technical experiments, break through and master key technologies such as manned round-trip missions between the Earth and the Moon, short-term lunar residence, and joint human-machine exploration, complete the multiple tasks of "landing, patrolling, collecting, researching, and returning", and form an independent manned lunar exploration capability.

▲Rendering of China's manned lunar mission (Photo source: China Manned Space Engineering Office)

Afterwards, China will explore the construction of a lunar scientific research test station, carry out systematic and continuous lunar exploration and related technical tests and verifications, promote the leapfrog development of manned space technology from near-Earth to deep space, and deepen human understanding of the origin and evolution of the moon and the solar system.

Through the construction of manned space projects (and space stations), my country has now mastered the rendezvous and docking technology. During the implementation of the Chang'e-5 mission, the world's first unmanned rendezvous in lunar orbit was successfully carried out. Through the Chang'e-5 lunar sample return, China also obtained a "return ticket" from the moon, and the implementation of the manned lunar landing project has become a natural progression.

Of course, when implementing the manned lunar landing project, the most critical link is still the return of the lunar module from the lunar surface to the lunar orbit and the successful docking with the new generation of manned spacecraft. Pang Zhihao said that the lunar module carrying two astronauts is much larger and heavier than the ascender for Chang'e 5's sampling return. Its design must not only have sufficient thrust, but also have redundant engines. Although it is not clear how many engines will be used, multiple engines will definitely be used to ensure that there is no risk of error. Since the propulsion module was used during the landing, the lunar module also had enough fuel, which can fully ensure that the lunar module can fly to the lunar orbit and dock with the spacecraft even if it is relatively heavy.

Pang Zhihao said that rendezvous and docking is a "double insurance" during my country's manned lunar landing project. First, the manned spacecraft can automatically rendezvous and dock with the lunar lander or the lunar module returning to the lunar orbit; second, the astronauts can also switch to manual docking when an accident occurs during the automatic rendezvous, and in addition to the two astronauts in the lunar module, another astronaut in the manned spacecraft in the lunar orbit can also cooperate in the operation, which further reduces the risk of the manned lunar landing project. After returning to the lunar orbit, the lunar module docks with the manned spacecraft, and then the two astronauts who landed enter the spacecraft from the lunar module, and the spacecraft separates from the lunar module. Then, when the spacecraft returns to the earth at a speed close to the second cosmic speed, that is, 11.2 kilometers per second, it can return safely through the "skipping stones" space return technology between the moon and the earth, which has been verified to be fully feasible by my country.

▲According to the China Manned Space Engineering Office, at 21:40 on July 20, after about 8 hours of extravehicular activities, Shenzhou 16 astronauts Jing Haipeng, Zhu Yangzhu and Gui Haichao worked closely together and successfully completed all the established tasks of the extravehicular activities with the support of the space station's robotic arm. Astronauts Jing Haipeng and Zhu Yangzhu have safely returned to the space station's Wentian laboratory module, and the extravehicular activities have been a complete success (Photo source/China Manned Space Engineering Office)

It is reported that before the manned lunar landing, China will also fully promote the fourth phase of the lunar exploration project, including the Chang'e 6, Chang'e 7 and Chang'e 8 missions. Wu Weiren, chief designer of China's lunar exploration project, revealed that Chang'e 6 will be launched around 2024 to carry out the first lunar back sampling and return mission; Chang'e 7 will be launched around 2026 to conduct a detailed survey of the environment and resources at the lunar south pole and strive to find water at the lunar south pole; Chang'e 8 will be launched around 2028 to conduct lunar resource utilization experiments and build a basic lunar scientific research station.

The Chang'e-8 and Chang'e-7 lunar probes will form a basic lunar research station, including a lunar orbiter, lander, rover, flyby and several scientific exploration instruments. China plans to use the moon as its main base to build a lunar Internet that integrates data relay, navigation and remote sensing, and effectively manage some resources and probes on the moon.

The fourth phase of the lunar exploration project will also lay a better foundation for my country to implement manned lunar landing. The maturity of related technologies and the increased reliability will provide more sufficient guarantees for my country's manned lunar landing project.

Manned lunar landing is a huge system engineering

Whether for China or the United States, implementing a manned lunar landing project is an extremely large-scale systematic project, involving thousands of research institutions and companies, and it also contains huge opportunities.

In order to achieve the goal of manned lunar landing, the China Manned Space Engineering Office has fully launched the deployment of research and development and construction work based on the early key technology research and development and program demonstration. These include a new generation of manned carrier rockets (Long March 10), a new generation of manned spacecraft, lunar landers, lunar suits and other flight products, as well as related test and launch facilities and equipment at a new launch site.

In order to make my country's manned lunar landing project produce greater economic and social benefits, my country's manned lunar landing project will also adopt an open and cooperative approach. It can be expected that a large number of new research results and technologies will be applied and greatly promote the development of my country's social economy.

▲ Schematic diagram of China's preliminary plan for manned lunar landing (Photo source: Visual China)

The "Apollo Moon Landing Program" of the last century had a profound impact on mankind through the research and development and application of some technologies. For example, the miniaturization of computers, which eventually led to the emergence of personal computers and smartphones, is one of the most outstanding examples.

We also hope that through China's manned lunar landing project, some technologies with profound impact on mankind will be born or promoted for application.