Abstract: The landing-ascending assembly of CE-5 experienced strong infrared radiation environment after landing on the moon. Because of the influence of thruster nozzle thermal conductivity, the pipe and solenoid valves faced high temperature environment. The propulsion system suffered oxidant gasification in the pipeline and thruster performance degradation or even inability to work, affecting the normal ascender attitude control after rising from the moon surface. In order to study the performance of thruster at high temperature, the compatibility of fluorine plastic spool and oxidizer at high temperature was investigated, reliability growth and reliability verification test methods for solenoid valves and thrusters were presented, the relationship between temperature and solenoid valve spool stroke was analyzed, the steady state and pulse performance of the thruster at high temperature environment was acquired, and the confidence lower limit of thruster reliability and the reliability of the propulsion system were evaluated under the condition of small sample. The results were verified by high temperature exhaust and the ascent attitude control. The lunar ascent mission was successfully completed. The research methods and ideas proposed have good engineering applicability.

Key words: lunar surface, high temperature, thruster, reliability, experimental study