The Chinese space station advances into the era of long-term manned residence
Our reporter Liu Yao
"People's Daily Overseas Edition" (October 28, 2021 Edition 09)
Recently, the Shenzhou 13 manned spacecraft was successfully launched and completed a radial rendezvous and docking with the Tianhe core module of the Chinese Space Station.
Three Chinese astronauts-Zhai Zhigang, Wang Yaping and Ye Guangfu entered the core capsule and started a six-month space life.
The China Space Station ushered in the second batch of visitors from the "hometown", ushering in the era of long-term manned residence.
In a blink of an eye, the Shenzhou 13 mission has been underway for more than ten days.
All over China, “capturing” the traces of space stations in the night sky has become a new fashion for many astronomy enthusiasts.
In space, Chinese astronauts will also carry out missions such as out-of-vehicle activities, space science experiments, and technical experiments during their stay.
Radial rendezvous and docking to jump "space waltz"
The rendezvous and docking of Shenzhou 13 with the Tianhe core module is the first radial rendezvous and docking implemented by a Chinese manned spacecraft in space.
Why do radial rendezvous and docking?
Beijing Space Flight Control Center Space Station Mission Chief Sun Jun said that during the later rotation of astronauts, two spacecraft will dock with the space station at the same time, and the radial rendezvous and docking can improve the channels and means of entering the space station.
Prior to this, the Tianzhou-2, Shenzhou-12, and Tianzhou-3 spacecraft all used forward or backward docking.
When docking, the core cabin and the spacecraft are "connected in a line."
After docking, Shenzhou 13 is perpendicular to the core cabin.
At present, the China Space Station has realized the operation of a core cabin, 2 cargo spacecraft, and 1 manned spacecraft, a total of 4 aircraft combinations.
According to experts, the Shenzhou spacecraft’s engines, control systems, and sensors are all designed specifically for docking with the space station in all directions. Only the Shenzhou spacecraft can perform radial rendezvous and docking with the space station.
Although the radial docking only changes the direction by 90 degrees, the difficulty of "space waltz" is not small.
During the forward and backward rendezvous and docking, the spacecraft has a 200-meter holding point. Even if the engine is not working, the spacecraft can maintain a stable attitude and orbit for a long time.
However, the radial rendezvous does not have a stable midway anchor point, and it is necessary to continuously control the attitude and orbit of the spacecraft, which consumes a lot of propellant and makes troubleshooting difficult.
During the radial rendezvous, the spacecraft must perform a wide range of attitude maneuvers from horizontal to vertical flight.
This puts forward higher requirements for the spacecraft's sensors.
Like the "eyes" of a spacecraft, sensors must have a high ability to recognize targets and not be disturbed by complex illumination changes.
The whole process of Shenzhou 13 radial rendezvous and docking is completed by the spacecraft intelligently and autonomously under the command of the guided navigation and control (GNC) system.
According to experts, in the future manned rendezvous and docking missions of the space station, radial rendezvous and forward rendezvous will be used alternately.
The successful implementation of the first radial rendezvous and docking is inseparable from the technical research and ground experiments of the Shenzhou spacecraft development team of the Fifth Academy of China Aerospace Science and Technology Corporation for several years.
In order to adapt to the different configurations of the space station assembly and the different docking states of the visiting spacecraft, the development team designed new rendezvous paths and orbiting modes, and added functions of orbiting, rapid rendezvous and docking, and radial rendezvous and docking.
More than a month ago, the combination of Shenzhou 12 and the space station completed an orbiting and radial rendezvous test, laying the technical foundation for the Shenzhou 13 mission.
Robotic arm mission upgrade "Space Class" continues to open
In the Shenzhou 12 mission, the "all-round" core cabin robotic arm has become a hot spot of concern from all walks of life.
Through two exit activities, the Shenzhou 12 mission tested for the first time the ability of astronauts and robotic arms to work together and the reliability and safety of supporting equipment related to exit activities.
In the Shenzhou 13 mission, the robotic arm is still one of the “protagonists” of the mission.
Lin Xiqiang, spokesperson for China's Manned Space Engineering and deputy director of China's Manned Space Engineering Office, said that the main purpose of the Shenzhou 13 mission includes the development of key technology tests for the assembly and construction of space stations such as manipulator-assisted module transposition and manual remote operation; Carry out 2-3 trips out of the cabin, install large and small robot arms and double-arm combination adapters and suspension devices to prepare for the subsequent space station construction tasks.
Zhou Jianping, the chief designer of China's manned space project, said that the tasks undertaken by the robotic arm will be more complicated in the future.
For example, after the space station is built, if the solar panels in the core module need to be put away, the astronauts and the robotic arm need to be coordinated.
Shenzhou 13 is China's longest manned flight so far. It will assess and verify the long-term ability of astronauts on the space station mission to stay in orbit for the first time.
Lin Xiqiang said that the 6-month stay in orbit is the normal stay period of the astronaut crew during the operation of the space station.
To this end, the Shenzhou 13 mission will further verify the health, life and work guarantee technology of astronauts staying in orbit for 6 months.
Lin Xiqiang said that the Shenzhou 13 mission will conduct a monthly comprehensive assessment of the health status of the astronauts according to the physical and mental characteristics of different individuals in different periods.
According to the evaluation results, the astronauts' weightlessness protection exercise program, the astronaut's nutritional meal plan and psychological support activities will be adjusted in a timely manner.
At the same time, for female astronauts participating in flight missions, we will focus on targeted design in terms of life security and health protection to ensure that female astronauts will fly for a long time, live a healthy life, and work efficiently.
Carrying out scientific experiments in space is also one of the main missions of the space station.
The Shenzhou 13 mission will conduct scientific and technological experiments and applications in the fields of space medicine and microgravity physics.
It is foreseeable that in the next work of the China Space Station, it is expected to obtain a large amount of scientific research data from different fields and produce high-level scientific results.
During the Shenzhou 10 mission in 2013.
Astronaut Wang Yaping once gave a unique "space teaching". 60 million elementary and middle school students across the country took classes on the ground, and the "space classroom" received enthusiastic responses.
This time following Shenzhou 13 to enter the space station, Wang Yaping will continue to start classes.
Lin Xiqiang said that the space station, as a national-level space laboratory, contains unique and extremely rich resources for popular science education.
The China Space Station is not only a research platform for global scientists to carry out space science, space technology, and space applications, but also a practical platform to encourage young people to love space, participate in exploration, and pursue science.
To this end, this mission planned a more diverse form of popular science education activities.
Complete the construction of the three-cabin combination of the space station before the end of next year
The Shenzhou 13 mission is the sixth mission in the key technology verification phase of the space station, and it is also the "final battle" of this phase.
In the future, China's manned spaceflight project will be fully transferred to the space station construction stage.
According to Lin Xiqiang, a total of 6 missions are planned during the construction phase of the space station. The first launch of the Tianzhou-4 cargo spacecraft to deliver supplies to prepare for the subsequent implementation of the Shenzhou-14 manned mission; the Shenzhou-14 crew is in During the orbit stay, Wentian and Mengtian experimental modules will be launched successively, docking with the Tianhe core module, and transposition of the cabin sections.
Before the end of 2022, China will complete the construction of the three-cabin combination of the space station, and then implement the Tianzhou 5 cargo supply and the Shenzhou 15 manned mission.
The Shenzhou 15 crew will carry out an on-orbit rotation with the Shenzhou 14 crew.
After a comprehensive assessment of the state of the space station, it will be transferred to the space station application and development stage.
In the future, China will also choose the opportunity to launch the space survey space telescope, co-orbit and fly independently with the space station for a long time, conduct sky survey observations, and stop at the space station for short-term replenishment and maintenance upgrades.
Zhou Jianping introduced that the resolution of the survey telescope is equivalent to that of the Hubble telescope, but the field of view of the survey telescope is more than 300 times larger than that of the Hubble telescope. Many international scientists are very interested.
"We have been promoting work in this area. We will open up scientific facilities and welcome more scientists to cooperate."
Lin Xiqiang said that China welcomes astronauts from other countries entering the Chinese space station and launching international cooperation.
It is believed that after the construction of the Chinese space station is completed, and it enters the stage of operation and application development, everyone will see astronauts from other countries participating in the mission of the Chinese space station.
Lin Xiqiang said that the completion of China's space station will provide a better platform for broader international cooperation including astronauts' joint flight.
At present, many countries and regions have put forward their wishes in this regard.
Sino-foreign cooperation in the selection and training of astronauts has already begun.
For example, Chinese astronauts went to Russia to participate in training.
For another example, astronaut Ye Guangfu of Shenzhou 13 participated in a cave experiment organized by ESA in 2016, and European astronauts also participated in a rescue training at sea organized by China in 2017.