On May 5, 2020, the Long March 5B carrier rocket developed for China's manned space station project successfully flew in Wenchang, Hainan, officially kicking off the "third step" mission of China's manned space project.

Xuantianlanyue, the sword refers to the sky. At 18:00 on May 5, Changzheng No. 5B carried a new-generation manned spaceship test ship and a flexible inflatable cargo return cabin test cabin, and ignited from the Hainan Wenchang space launch site. After about 488 seconds, the load combination and the rocket successfully separated into the predetermined orbit, and the first flight mission of China's space station stage succeeded.

The load mass delivered by the Long March 5B rocket is about 22 tons. This is the first time that a Chinese or Asian rocket has launched a spacecraft with more than 20 tons. It further laid the position of the Long March 5 series rocket in the world's first echelon of rocket carrying capacity.

The success of its first flight mission kicked off the prelude to the space station orbital construction phase of the flight mission. The Chinese space station will be completed around 2022, and will also have an optical module for common orbit flight, which can complete surveys of a wide range of celestial bodies within 10 years.

The new-generation manned spaceship test ship in this load is the "trial version" of the new-generation manned spaceship. The new-generation manned spaceship is equivalent to a "space bus". In the future, it can transport 6-7 astronauts at a time when performing a low-Earth orbit mission. It can also be turned into a "space truck" according to mission requirements, and the return capsule can be reused in the future.

"Thin" nearly 20 tons of "Big Head Brothers", focusing on the launch of the space station cabin section

The Long March 5B rocket was developed by the China Academy of Launch Vehicle Technology (the First Academy) affiliated to China Aerospace Science and Technology Group, and is mainly used for major space launch missions such as the cabin section of China's space station. The total length of the rocket is about 53.7 meters, which is equivalent to 18 floors high, the take-off mass is about 849 tons, and the near-Earth orbit carrying capacity reaches 25 tons.

The Long March 5 series of launch vehicles mainly include the Long March 5 and Long March 5 B rockets. The two brothers' rockets are "fat", with a core diameter of 5 meters and four boosters with a diameter of 3.35 meters.

However, the most intuitive difference is the configuration and height. The fairing of Changzheng No. 5 B is larger than that of Changzheng No. 5. This "brain head" is 20.5 meters long and 5.2 meters in diameter. It is newly developed according to the mission requirements of the space station. It is the largest fairing in China, which is more than 10 meters long. 4 The core compartment of Mido's space station was loaded.

Compared with the Long March 5, the Long March 5 B rocket is about 3 meters shorter, reducing the second sub-stage and the inter-stage section. It is China's first "first-and-a-half" rocket, of which the "half-stage" comes from the booster.

The more advanced Long March 5 is good at "running long distances", and can send "passengers" to a geosynchronous orbit 36,000 kilometers high, the moon 380,000 kilometers away, and Mars, which is also tens of millions of kilometers away.

The one-less Long March 5B is a "sprinter". Although it is nearly 20 tons thinner than the Long March 5, it focuses on sending "passengers" to orbits around 200-400 kilometers near the earth. It is the main battlefield for the construction of China's space station.

At present, China's rockets mostly use multi-stage forms, such as the two-stage rocket Long March 2, the two-stage half rocket Long March 2F, the three-stage rocket Long March 3A, the three-stage half rocket Long March 3B, and the four-stage rocket Long March 11. number.

The Long March 5B rocket is the only rocket in active service in China that is directly in orbit. Compared with the "relay" of a multi-stage rocket, it can be completed from ignition to orbit, which not only enriches the spectrum of a new generation of launch vehicles in China, but also has the characteristics of stepless separation, which also improves the reliability of the system.

The same "heart" and different working conditions, the pressure of the "ice arrow" engine rises and falls

With only "one and a half", the Long March 5B rocket can send nearly 22 tons of spacecraft to the sky, making China one of the very few countries that master the technology of direct and accurate orbital thrust of the "one and a half" rocket. This is due to the reasonable combination of the core level using hydrogen and oxygen propellant and the booster using liquid oxygen kerosene propellant. The two large thrust hydrogen-oxygen engines at the core level directly affect the final orbit of the spacecraft.

Under the same launch weight, the higher the specific impulse of the rocket engine, the stronger the rocket's carrying capacity. The specific impulse of the hydrogen-oxygen engine can be said to be a leader, but its development is also very difficult. As the "ice arrow" that also uses liquid hydrogen, liquid oxygen and other low-temperature propellants, the particularity of the mission undertaken by the Long March 5B rocket puts higher requirements on the core-level large thrust hydrogen-oxygen engine.

"Zero window" refers to a launch window with a launch time range of zero, which requires that the rocket must be fired into the air without any delay. The rendezvous and docking missions in manned spaceflight projects must not have any slight error in time, otherwise they may miss.

The oxyhydrogen engine used in the core stage of the Long March 5B rocket must ensure that the pre-cooling and other pre-launch work are interlocked and smooth, and the launch window is not delayed, so as not to cause a greater cost to adjust the orbit.

At the same time, the Long March 5B rocket is lighter than the Long March 5 rocket, but the takeoff thrust is the same as the Long 5 rocket. Use the same force to lift something lighter, the acceleration is naturally faster. After the booster was separated, the acceleration of the rocket reached its lowest instantaneously.

Wang Weibin, deputy chief designer of the fifth rocket of China Aerospace Science and Technology Corporation, said that the entrance of the engine faced the pressure of ups and downs like a roller coaster, which brought great challenges to the stable and reliable operation of the engine.

In order to meet these challenges, the hydrogen-oxygen engine development team has overcome these difficulties one by one through a large number of research improvements and experimental verifications to further improve the reliability and stability of the engine work. In addition, the remote operation method adopted by the ground equipment and other systems also guarantees the safe and smooth progress of the engine pre-cooling and other links.

A multi-purpose ship to and from the "space bus", the future return cabin can be reused

The successful launch of the Long March 5B rocket carried a new-generation manned spaceship test ship, a flexible inflatable cargo return cabin test cabin, and more than 10 experimental loads. According to Ji Qiming, assistant director of the China Manned Space Engineering Office, according to flight procedures, the test module and the test vessel will return to the Dongfeng landing site on May 6 and May 8, respectively, after completing the on-orbit test.

Final assembly site

The flexible inflatable cargo return cabin test cabin was developed by the Second Research Institute of China Aerospace Science and Industry Group Co., Ltd. It is the tester of China's new space transportation aircraft. This mission will carry out the key technology of the reentry of the inflatable deployable return aircraft. verification.

The new-generation manned spaceship test ship is a "test version" of the new-generation manned spaceship, and was developed by the China Academy of Space Technology (fifth institute) under the China Aerospace Science and Technology Corporation. The spaceship is nearly 9 meters high, the body is about 4.5 meters in diameter at its fattest point, and weighs over 20 tons. This flight test mission will carry out flight verification on key technologies related to the high-speed reentry and return of the test vessel for heat prevention, control and group umbrella recovery.

"We are mainly using this test ship to verify some key technologies in the future. For example, reentry heat protection technology, compared with the Shenzhou spacecraft, (this time) we will send the test ship to a higher orbit, let It re-enters (atmosphere) at a higher speed to test heat protection technology. "Said Zhou Jianping, chief designer of China's manned aerospace engineering.

In addition, "Shenzhou spaceship has a 1200 square meters of deceleration umbrella, this test boat will have three umbrellas of this size, how to reliably and safely open these three umbrellas, this is also the group umbrella recovery technology to be verified this time."

Test site

Since the launch of the manned spaceflight project in 1992, China has formed multiple types of spacecraft supported by the Shenzhou spacecraft, space laboratory, and cargo spacecraft, laying the foundation for the official launch of the construction of the space station.

The new-generation manned spacecraft is a fully upgraded round-trip transportation between the earth and the earth. With the powerful ability of "shipping people + freight".

If the Shenzhou spaceship is compared to a "space vehicle" exclusive to astronauts, then the new generation of manned spacecraft is a "space bus". In the future, when carrying out low-Earth orbit missions, it can transport 6-7 astronauts at a time, which is carried by the Shenzhou spacecraft. Twice the capacity.

It can also change from a "space bus" to a "space truck" according to mission requirements, deliver a large amount of supplies to the space station, or bring back test samples made by space engineers at the space station to Earth.

Vibration test

In order to make the new-generation manned spacecraft multi-functional, the China Academy of Space Technology proposed the overall design scheme of the new-generation manned spacecraft based on modular design, "merging similar items" of flight function requirements, and constructing "return cabin + service cabin" The new configuration of the two cabins.

The new configuration integrates power, propulsion, fuel resources and other sub-systems with different performance indicators due to different tasks into the service cabin to achieve a unified return cabin configuration with different service cabin modules to meet multi-task demand goals and greatly shorten the development cycle It can also reduce development costs in batch mode.

The return module is the command center of the whole ship and the place where the astronauts live and live. Compared with the bell-shaped return capsule of the Shenzhou spacecraft, the return capsule of the new-generation manned spacecraft is an inverted cone blunt head aerodynamic shape design. The inverted cone air lift is greater and can rely on air when returning at high speed at the second cosmic speed Resistance decelerates, landing more smoothly and accurately.

The return cabin of the new generation manned spacecraft is designed to be reusable. Star sensors, computers and other high-value equipment have been optimized from the service cabin to the return cabin for installation, so that they can be recycled after the return cabin returns. Return to the outside of the cabin to cover the new lightweight heat-proof structure independently developed by China. After performing the task, only the lightweight heat-proof structure needs to be replaced, and the manned space flight mission can be executed again after strict and strict testing.

The construction of the space station will be completed around 2022, with a common orbit optical capsule

On September 21, 1992, the Standing Committee of the Political Bureau of the CPC Central Committee approved the implementation of China's manned spaceflight project in accordance with the "three-step" development strategy.

The first step is to launch a manned spacecraft, build a preliminary supporting pilot manned spacecraft project, and carry out space application experiments; the second step is to break through the astronaut's space movement technology, the spacecraft rendezvous and docking technology, launch the space laboratory, and solve There is a certain scale of short-term manned space application problems; the third step is to build a space station to solve the large-scale, long-term manned space application problems.

After more than 20 years of independent development and continuous struggles, China has organized 16 major flight missions, achieved a total of 14 space flight and safe return for 11 astronauts, and successfully completed all the first and second scheduled tasks.

The success of the first flight mission of the Long March 5B carrier rocket ushered in the "opening door" to the implementation of the "third step" development strategic mission of the manned spaceflight project. 3. Lay a solid foundation for the launch of the experimental module.

Ji Qiming introduced that China's space station will be completed around 2022, and a total of 12 flight missions are planned. After this mission, we will launch the Tianhe Core Module, Wentian Experimental Module and Mengtian Experimental Module successively to carry out the on-orbit assembly and construction of the basic configuration of the space station; Spaceship, astronaut crew rotation and cargo replenishment.

The construction of the Chinese Space Station was more than 20 years after the launch of the first module of the International Space Station in 1998. However, Zhou Jianping believes that although the Chinese space station uses contemporary technological achievements in research and development, although the construction time is later than the international space station, it has fully considered the role of technological progress in the development of aerospace.

China has used the achievements of more than 20 years of scientific and technological development and technological progress in energy technology, renewable life support technology, space exploration technology and scientific research equipment. Therefore, the Chinese space station will stand at a higher technological and scientific starting point.

For example, in the future, the Chinese Space Station will be equipped with an optical capsule for common orbit flight. "This optical capsule is actually a survey telescope. Its resolution is comparable to that of the well-known Hubble telescope, but its angle of view is It is more than 300 times larger than the Hubble telescope, and it can complete surveys of large-scale celestial bodies within 10 years. "Zhou Jianping said.

At this stage, the core module of China's space station has completed the assembly of the prototype product, and the initial prototype development of the Wentian experimental module and the Mengtian experimental module is being carried out; The crew of the astronauts have been selected and are conducting mission training. In addition, the selection of China's third batch of astronauts will also be completed around July this year.

The Long March 5B rocket will be responsible for launching the core module and the experimental module of the space station. After the completion of the technical plan verification for the first flight mission of the Long March 5B rocket, the Long March 5B Yao 2 to Yao 4 missions will complete the launch missions of the three modules of the space station.

At the same time, this year the Long March V series launch vehicle "family" has a major mission and will perform three launch missions. Following the first flight of the Long March 5B rocket, the Long March 5 Yao-4 rocket will launch China's first Mars probe in the second half of the year. Before the end of the year, the Long March V rocket will also have its fifth launch, sending the Chang'e V lunar probe to the moon to achieve sampling and return to the lunar surface.

Article transferred from Netease Military Source: Peng Mei News Network