Xinhua News Agency, Beijing, September 17th: Newly expanded pump unit, third-generation relay terminal… A scan of the second mission of the Shenzhou 14 astronaut crew to leave the cabin
Xinhua News Agency reporters Hu Zhe and Song Chen
On September 17, Shenzhou 14 astronauts Chen Dong, Liu Yang, and Cai Xuzhe worked closely together to complete all the scheduled tasks for the second extravehicular activity, and the extravehicular activity was a complete success.
During the astronaut’s out-of-vehicle activities, tasks such as the installation of the extravehicular power handle, the installation of the load circuit expansion pump set, and the verification of the extravehicular rescue were completed successively, which further tested the astronaut’s ability to work together with the small robotic arm, and verified the Wentian experimental cabin. Functional performance of support equipment related to airlock and exit activities.
On September 17, Shenzhou 14 astronauts Cai Xuzhe (top) and Chen Dong (bottom) were operating outside the cabin at the same time at the Beijing Space Flight Control Center.Photo by Xinhua News Agency reporter Guo Zhongzheng
The most notable of these is that the astronauts installed an extended pump set developed by the Fifth Academy of Aerospace Science and Technology Group for the Wentian experimental cabin. Different from the Wentian experimental cabin thermal control expansion pump set installed by the astronauts for the first time out of the cabin, this time an expansion pump set was installed in the outer load cooling circuit of the Wentian experimental cabin.
Why install an extended pump set outside the Wentian experimental cabin? This is because the space station mission lasts for more than 15 years, and as key components of the cooling circuit, pumps, valves, filters, sensors, etc. need to be replaced on-orbit. The liquid circuit equipment must be installed in the cabin to be in the envelope of the fairing, instead of the sealed cabin being filled with equipment and pipeline cables, if the astronauts in heavy cabin suits drill into the unsealed cabin to change the liquid circuit equipment , the difficulty can be imagined.
To this end, the thermal control designers of the Space Station of the Fifth Academy of Aerospace Science and Technology Group made bold innovations and proposed a new idea: install a set of pump valves in the cabin to support the early operation of the circuit, and then leave an electromechanical interface on the outer wall of the cabin. , choose an opportunity to add a set of pump sets outside the cabin, that is, the so-called expansion pump set outside the cabin.
After the expansion pump set is installed, the Wentian experimental cabin will give priority to the use of the expansion pump set, and an extended pump set will be replaced after failure or expiration of the service life, and the pump set in the cabin will be used as a backup to ensure the stable operation of the space station in orbit.
Although in the space environment, no matter how heavy the box is, it is still difficult for astronauts in space suits to operate a large box and connect the electromechanical hydraulics to the cabin. Especially in the connection of the liquid circuit, the spring force and liquid pressure in the disconnector are not small, and the exiting activity itself is inconvenient, and the astronauts cannot directly plug in by their own strength.
Shenzhou 14 astronaut Cai Xuzhe exits the capsule, taken at the Beijing Space Flight Control Center on September 17.Photo by Xinhua News Agency reporter Guo Zhongzheng
The designers of the Fifth Academy of Aerospace Science and Technology Group have carried out a large number of experiments to verify, and constantly improve the product design. When installing the expansion pump set, the astronauts do not need to use any tools, nor do they need to precisely aim or shift left and right. Positioning, dialing the hook to lock, turning the handwheel to plug in, pulling the handle to connect the liquid” four steps, except for the time for confirmation by the ground personnel, this arduous task can be successfully completed in less than one minute, which saves time and effort.
After leaving the space, the astronauts will face the severe test of the space environment, and there is no room for mistakes. Therefore, it is particularly important to establish high-speed and timely measurement and control communication with the ground when carrying out vehicular activities.
To ensure the real-time smooth communication between astronauts and the ground, it is necessary to rely on the third-generation relay terminal products developed by the Fifth Academy of Aerospace Science and Technology Group for the space station Wentian experimental module. It realizes relay communication by establishing relay links with relay satellites Tianlian-1 and Tianlian-2. This is like building a communication “skyway” between the ground and relay satellites, relay satellites and astronauts in space, which plays an important role in ensuring continuous communication between the ground and the astronauts.
After the space-based measurement and control communication system established by the relay terminal is completed, it can ensure that the Wentian experimental module maintains real-time communication with the ground most of the time.
Yu Xiaochuan, the manned aerospace engineering task leader of the Xi’an Branch of the Fifth Academy of Aerospace Science and Technology Group, introduced that the original ground measurement and control station and offshore measurement and control station of the manned aerospace project had a relatively small measurement and control coverage. Always keep in touch.
In addition, during the construction phase of the space station, it will become a normal activity for astronauts to go out and carry out operations such as extravehicular maintenance and equipment replacement. The relay terminal of the space station Wentian experimental module adopts an integrated and modular design idea, which is convenient for astronauts to maintain and replace while ensuring the quality of transmission signals.
[Editor in charge: Xu Dan]