A "sky bridge" connects the "natural chasm" to make space exits easier

On November 17, 2022, the three modules of the Chinese space station gathered in the sky, and the "T" basic configuration was assembled on orbit. The Shenzhou XIV astronauts successfully went out of the cabin for the third time, which was even more exciting. During this extravehicular mission, the astronauts completed the connection of the entire station's extravehicular autonomous transfer path , and performed cross-cabin extravehicular operations for the first time , once again allowing the world to feel the " people-oriented " design concept of China's aerospace technology.

▲Astronauts are installing the inter-cabin connection device

This time, 18 extravehicular maintenance tools of 15 categories developed by the General Assembly and Environmental Engineering Department of the Fifth Academy of China Aerospace Science and Technology Corporation (hereinafter referred to as the Fifth Academy) provided strong support for the successful completion of the mission. Among them, in addition to the well-known "artifacts" such as foot limiters and extravehicular power tools, there are also two inter-cabin connection devices praised by the developers as "space bridges" that made their debut and played an important role in the mission. They not only help astronauts build cross-cabin transfer paths between the Tianhe core module and the Wentian laboratory module, and between the Tianhe core module and the Mengtian laboratory module, turning the "natural chasm" outside the cabin into a thoroughfare in seconds, but also pave the technical road for the subsequent more complex cross-cabin missions of the space station.

See how the "Space Skybridge" turns the "natural chasm" outside the cabin into a "sky-highway" in seconds

The "T" configuration of the Chinese space station is special and complex. To successfully complete multiple extravehicular tasks from the outer wall of one module to another is undoubtedly full of challenges for astronauts wearing heavy space suits. In order to allow astronauts to freely "shuttle" between modules to complete various extravehicular tasks, building an inter-cabin transfer path has become the first choice. To this end, the Fifth Academy's extravehicular maintenance tool development team specially designed a flexible and safe " space bridge " for the space station, which is the inter-cabin connection device . Don't underestimate this "artifact", it is currently the longest extravehicular tool for the space station, and it is a key equipment that can carry out space on-orbit maintenance operations across modules. With it, the "natural moat" between cabins becomes a "sky stairway" in seconds .

▲Intercabin connection device

However, the design of the inter-cabin connection device is not accomplished overnight. It must not only meet the requirements of the long-distance connection length between the node cabin and the Wentian cabin, and between the node cabin and the Mengtian cabin, but also fully consider the restrictions on the product size of the uplink storage space during the launch process, and facilitate the installation of astronauts outside the cabin. The design difficulty is self-evident. " The road is made by ourselves! " Faced with stringent design requirements and limited technical experience, the development team has finally determined the technical solution of folding up and unfolding outside the cabin after multiple rounds of research. That is: the solution of folding and loading the cargo bag during the uplink can not only meet the space requirements, but also properly protect the product during the uplink; when the astronauts are outside the cabin, they can unfold it through convenient operation and set it up between the two cabins. At the same time, considering that the relative position or attitude between the two cabins may change in the microgravity environment on orbit, the relative distance between the device installation interfaces on the outer walls of the two cabins will also change accordingly. Therefore, the developers designed two ingenious adjustment mechanisms for the device to ensure reliable connection and intact tools.

The "space bridge" is cleverly designed with multiple "locks" for greater safety

Since it is known as the "space bridge", its high reliability and non-interference with astronauts are well-deserved. When the astronauts first boarded the space station, they were busy "unlocking" various equipment around them, but the inter-cabin connection device was " firmly locked " for the safety of the astronauts' extravehicular work. Due to the needs of the astronauts' extravehicular tasks, it must not only be locked when docking with the interfaces at both ends of the cabin, but also be locked when hanging on the operating table and moving with the robotic arm over a large range to maintain the folded state, and also be locked when unfolding from the folded state to the flat state to maintain the erected state. This series of "locking" actions are completed with the help of the multiple safety locks set on the inter-cabin connection device.

According to the developers of the Fifth Academy, "a total of 13 locks are designed for the entire device, especially 4 locks are designed at the installation interfaces between the two ends of the device and the cabin to ensure that the connection is absolutely reliable. In addition, the paddles of the locking switch and the standard parts on the main structure of the device have been carefully designed to effectively avoid accidental contact during the transfer of astronauts and ensure the successful completion of the extravehicular mission."

Everything for astronauts' "space bridge"

Demonstrating the “people-oriented” design concept of China’s aerospace technology

Manned space flight is a matter of life and death. As the inter-cabin connection device of the "space bridge" for cross-cabin operations, its on-orbit safety has always been the most concerned issue for the development team of the Fifth Academy's extravehicular maintenance tools. " Can it be done better? " is a soul-searching question often asked by the developers during exchanges and discussions. It is their greatest wish to be able to effectively support astronauts to complete extravehicular missions safely, conveniently and efficiently.

In order to make the "Space Bridge" go to space confidently and become an easy-to-use extravehicular equipment for astronauts to use when going out of the cabin, during the detailed design and ergonomics evaluation of the inter-cabin connection device, the development team fully drew on the valuable on-orbit application experience of the Shenzhou XII astronaut crew and the Shenzhou XIII astronaut crew for the extravehicular mission, and carried out multiple rounds of iterative design and ergonomics verification of the inter-cabin connection device based on the use requirements of the astronauts' extravehicular mission. With their careful polishing, the position of the switch, the direction of the logo, the size of the label font, the position of the operation, the habitual posture of the astronauts... every detail has become more perfect, making the "Space Bridge" more and more intimate.

▲The development team is conducting a full-process simulation of the on-orbit installation of the inter-cabin connection device

In the field of environmental testing, the Fifth Academy's extravehicular maintenance tool development team fully utilized the advantages of cabin power and tailored a "special test paper" for the inter-cabin connection device. In addition to the basic mechanical and thermal environmental tests, which are "basic questions", they also designed "advanced questions" for the inter-cabin connection device. The operator wears simulated gloves in extreme high and low temperature environments and operates the unlocking and locking of each switch one by one to test the function of each switch, thereby ensuring a comprehensive and reliable design and a smooth user experience. Before the spacecraft entered orbit, it had undergone many rigorous tests on the ground, so even if it was its first appearance, it was "confident" enough to ensure the successful completion of the mission.

After careful deduction and rigorous verification, the "Space Bridge" went to space. This highly integrated "Sky Bridge" provides strong support for astronauts to transfer conveniently and safely between the three cabins. The extravehicular tool development team is also confident that it will undertake subsequent development tasks and contribute to the long-term stable operation of the space station and scientific research on orbit.