In the early morning of May 10, the Tianzhou-4 cargo spacecraft was successfully launched by the Long March 7 Yao-5 carrier rocket at the Wenchang Cosmodrome in Wenchang, Hainan. After several hours of flight, Tianzhou-4 successfully completed the backward docking with the core module of the space station.
At 1:56 a.m. on May 10, the Long March 7 carrier rocket lifted the Tianzhou-4 cargo spacecraft into the air. Photo by Xinhua News Agency reporter Guo Cheng
This is the first launch of the Chinese space station construction mission in 2022, marking the official start of the full construction of the Chinese space station.
Highlight 1: What is the important mission of Tianzhou 4?
The Tianzhou-4 mission is the opening battle for the opening of the construction stage of the Chinese space station, and it is also a key battle to fully complete the construction of China's space station and achieve the "three-step" strategic goal of manned spaceflight project, which will lay a solid foundation for steadily advancing the engineering mission of the mainland space station and building a national space laboratory.
Yang Sheng, chief designer of the Tianzhou cargo spacecraft system of the Fifth Academy of Aerospace Science and Technology Group, introduced that as the ground logistics supply spacecraft of the space station, the Tianzhou cargo spacecraft adopts a spectral scheme and designs three kinds of cargo compartment modules that meet the needs of different cargo transportation, including fully sealed, semi-sealed semi-open and fully open cargo modules, and combines with the universal propulsion module to form a fully sealed cargo spacecraft, a semi-sealed semi-open cargo spacecraft and a fully open cargo spacecraft.
"The Tianzhou-4 cargo spacecraft is a fully sealed cargo spacecraft, which is the cargo spacecraft with the largest cargo transportation capacity and the most comprehensive on-orbit support capability in service." Yang Sheng said that it undertakes the mission of providing material support for the Shenzhou 14 crew, supporting the operation of the space station and carrying out space science experiments, and will implement cargo replenishment and propellant replenishment during the docking of the space station.
The picture shows the development site of Tianzhou No. 4. (Courtesy of the Fifth Academy of Aerospace Science and Technology Group)
Watch point two: What "gift packages" are brought to the space station?
In order to ensure the smooth completion of various tasks, what "gift packages" did Tianzhou 4 carry? Yang Sheng introduced that in this mission, Tianzhou-4 loaded more than 200 pieces (sets) of cargo in total, including cargo packages and direct installations, carrying about 750 kg of supplemental propellant, and the total weight of uplink materials was about 6,000 kg, which will provide material support for the 3-person on-orbit residence of Shenzhou XIV crew for 6 months, the assembly and construction of the space station, and the development of space science experiments.
In order to ensure the safe delivery of goods to the "Space Home", Tianzhou-4 adopts a variety of cargo loading methods such as cargo bags, brackets, and storage boxes, and the types and quantities of goods can be dynamically configured according to the needs of the space station. At the same time, it also has the ability to undertake the space station attitude orbit control, grid-connected power supply, space station telemetry, data transmission support, space science experiments and other tasks.
It is worth noting that Tianzhou-4 has a more humanized design - according to the on-orbit use opinions of the astronaut crew, in order to find goods more convenient and intuitive, Tianzhou-4 has increased the color marking of the cargo bag through the color design of the label and handle; in order to facilitate the operation of astronauts in orbit, Tianzhou-4 began to add buckle belts to the adapter board and corresponding shelves to achieve convenient anti-drift; in order to facilitate storage and storage, the buffer foam in the bag was miniaturized and optimized, and the gas column buffer scheme was added to reduce weight.
Watch point three: how to accurately realize the "kiss of space" by "ten thousand miles through the needle"?
In order to deliver "fresh goods" in the vast space, Tianzhou-4 needs to "wear the needle in a thousand miles", accurately, safely and reliably dock with the space station, and realize the "kiss of space", which is a test for the docking mechanism of the cargo spacecraft.
The relevant designer of the Eighth Academy of Aerospace Science and Technology Group, which undertakes the development of the docking mechanism subsystem, said that the construction of the continental space station is like "building blocks", and the "joints" connecting the various modules are the docking mechanisms. At the beginning of the design of the docking mechanism, the designer fully considered that the future construction of the space station needs to adapt to various tonnages and various ways of docking from 8 to 180 tons.
The huge docking energy generated during the docking process puts forward higher requirements for the buffer energy consumption capacity of the docking mechanism. In order to make the two heavyweight spacecraft "light and elegant" when docking, the designers have systematically proposed the control idea of controllable damping through a large number of technical research and program demonstration, and through buffering and other measures, they can not affect the capture performance, but also offset the energy of the impact, breaking through this key technology.
Highlight 4: What are the changes in the Long March 7 carrier rocket?
The Long March 7 carrier rocket and the Tianzhou cargo spacecraft are already a pair of "old friends". Shao Yetao, the overall chief designer of the Zhengqi carrier rocket, the first president of the Aerospace Science and Technology Group, introduced that this is the fourth time that the Long March 7 carrier rocket and the Tianzhou cargo spacecraft have joined hands to go to space, and the "space express brother" and its passengers have a very tacit understanding, and the overall technical state of the rocket is also stable.
In order to meet the operational needs of the future space station, the Long March 7 Yaowu carrier rocket developed by the First Academy of Aerospace Science and Technology Group optimized the pre-launch process, reducing the test and launch cycle by 4 days, from the original 31 days to 27 days, which is also the first time that the Long March 7 carrier rocket has completed testing and launching within one month.
On May 7, the Tianzhou-4 cargo spacecraft and the Long March 7 Yao-5 carrier rocket combination were in vertical transit. Xinhua News Agency (Photo by Yang Zhiyuan)
In this mission, the rocket has a total of 17 technical status changes, such as pre-launch process optimization and reliability improvement. Meng Gang, commander-in-chief of the Zhengqi carrier rocket of the First President of the Aerospace Science and Technology Group, introduced that reducing the rocket test and launch cycle by 4 days is a major process improvement task of the Long March 7 Yaowu carrier rocket, which not only challenges the comprehensive performance of the rocket, but also tests the resilience of the launch team members in a high-intensity working environment.
Highlight 5: When will the space station be built in orbit?
According to the mission arrangement, after the launch of the Tianzhou-4 cargo spacecraft, the Shenzhou 14 manned spacecraft will be launched in June, the space station Wentian experimental module will be launched in July, and the space station Mengtian experimental module will be launched in October. This will be followed by the launch of the Tianzhou-5 cargo spacecraft and the Shenzhou-15 manned spacecraft.
According to reports, the two crews of Shenzhou 14 and Shenzhou 15 are composed of three astronauts, who will fly in orbit for 6 months, and will realize the rotation of on-orbit crews for the first time to achieve uninterrupted manned presence. Two crews of six astronauts will stay in orbit together for 5 to 10 days.
"After the completion of the orbital construction of the space station this year, the project will move to the application and development stage of more than 10 years. The initial plan is to launch two manned spacecraft and two cargo spacecraft per year. Astronauts should stay in orbit for a long time, carry out space science experiments and technical experiments, and take care of and maintain the space station. Hao Chun, director of the China Manned Space Engineering Office, said.
In addition, in order to further enhance the comprehensive capability and technical level of the project, the mainland will also develop a new generation of manned carrier rockets and a new generation of manned spacecraft. Among them, the return capsule of the new generation of manned launch vehicles and the new generation of manned spacecraft can be reused; the comprehensive capabilities of the new generation of manned spacecraft will also be greatly improved, which can carry 7 astronauts. In addition, larger-scale space research experiments and new technology experiments will be carried out.
"Manned spaceflight engineering is a great undertaking that is 'both tall and grounded.'" Hao Chun said that in the future, the Chinese space station will also carry out a large number of scientific experiments and new technology verifications such as space life science, space materials science, and aerospace medicine, and is expected to achieve major achievements and breakthroughs in scientific exploration and applied research. At the same time, these technologies will be more transformed to serve the social and economic development and the national economy and people's livelihood. (Reporters Hu Zhe, Li Guoli, Song Chen, Chen Kaizi)