Design and implementation of hot-swappable maintenance for key equipment of manned spacecraft

With the participation of astronauts, the maintenance and replacement of equipment provides an effective way for the safe operation of manned spacecraft. The working life of spacecraft such as manned space station on orbit is at least more than ten years, even up to fifteen or twenty years. Although all kinds of key equipment are designed for long life, but due to long continuous working time and other comprehensive reasons, the maintenance of key equipment is inevitable on orbit. To guarantee the security of astronauts, it is imperative that electrical appliances utilizing the power bus be deactivated during the maintenance process. This action will result in the disruption of crucial functions of vital equipment, thereby posing potential threats to the flight safety of the spacecraft. This paper presents a design method for hot-swappable maintenance of key equipment in manned spacecraft. The topology and interface of the power distribution system supporting hot-swappable maintenance of spacecraft are designed. The design method for the hot-swappable maintenance of equipment itself is proposed. The design method is illustrated by the example of the command bus unit, including circuit design, structure design, maintenance operation design, and maintenance process. Finally, the hot-swappable maintenance process of the command bus unit is simulated. In addition, the maintenance operation experiment was conducted on the spacecraft system model and spacecraft on orbit, verifying the correctness and rationality of the system and equipment maintenance design. The design method proposed in this paper can provide reference for the design of the maintainability of key equipment for subsequent manned lunar landing and other missions.