It was learned from the Sixth Academy of Aerospace Science and Technology Group on the 20th that recently, the gas cylinders of the electric propulsion system of Tiangong Space Station completed the on-orbit installation task, and the 801 Institute of the Academy used the "ventilation" method for the first time to complete the supply of xenon propellant for the electric propulsion system.
Electric propulsion system, also known as electric propulsion engine, its working principle is to convert inert gas such as xenon into charged ions, and then accelerate and eject these ions to generate propulsion, and then complete the attitude control and orbit of the spacecraft. tasks such as corrections and orbit maintenance.
According to reports, the design team of the 801 Institute of the Sixth Academy of Aerospace Science and Technology Corporation, which is in charge of developing the electric propulsion system of the general space station, chose the method of "breathing" on orbit, that is, when the propellant of the gas storage module assembly is exhausted, On-orbit cylinder replacement will be performed automatically by a robotic arm. However, because there are many uncontrollable factors in the space environment, in order to ensure the smooth replacement of the gas storage module, astronauts can also replace it manually.
The team creatively proposed a simplified version of the floating docking form, that is, the initial positioning of the robotic arm is achieved through a rough positioning guide device, and then further corrected through autonomous fine positioning. This form greatly improves the reliability of the docking, and the accuracy can be guaranteed to meet the requirements even if it is disassembled and assembled many times in orbit.
A picture of the ignition status of the electric propulsion system of the space station taken by the panoramic camera outside the Tianhe core module. (Photo courtesy of the Sixth Academy of Aerospace Science and Technology Group)
At the same time, since the gas cylinders are installed on a unified interface, in principle, as long as the interface requirements are met, the electric propulsion system of the space station can install gas cylinders with different volumes, different working pressures, and different filling gases. This design endows the air storage module with "versatile" and versatile characteristics, which not only greatly increases the life and reliability of the electric propulsion system, but also enriches the system's functions.