Based on the composition-microstructure multilevel design and the fabrication technology of large-scale components, several kinds of boron nitride ceramic matrix composites have been developed with in-situ reinforced phases such as silicon oxide, rare earth silicate and rare earth aluminosilicate glass. Novel "co-enhancement" and "double glass phase reinforcement" strengthening mechanisms have been discovered, which stimulates the breakthrough to overcome the disadvantages of low strength, low thermal shock resistance and weak plasma etching resistance of boron nitride. The developed composites were material was assembled on the satellite used for completing the first successful on orbit demonstration and verification task by Hall electric propulsion, enabling China to independently master the propulsion technology after Russia, the United States and Europe. Then it was applied on satellites in subsequent major space programs. In order to further develop electric propulsion system on the space station, a lot of work has been carried out on composition and microstructure modification, large-size component preparation, material homogenization and quality stability control. The critical performance of newly developed composite is significantly ahead of similar products developed by other domestic universities, institutes and the United States.

On April 29, 2021, the "Tianhe" core module of China's "Tiangong" space station was successfully launched. The boron nitride ceramic matrix composite developed by our division was adopted in the Hall thruster chamber in supporting electric propulsion system in "Tianhe" core module, which indicates the remarkable contributions on application of Hall electric propulsion technology on the space station for the first time in the world.

Fig. 1. The boron nitride ceramic matrix composite was adopted in the Hall thruster chamber in supporting electric propulsion system in "Tianhe" core module.