Research on the fault diagnosis method for spacecraft propulsion system

Several key problems of fault-diagnosis expert-system used in the propulsion system of spacecraft and the methods for solving them were discussed. The fault tree was used for the fault identification, and the forecasting tree was used for the fault forecast. As to the rules for diagnosis, they can be divided into two types: (1) those that have the district feature, such as for gas system, for propellant feed system, and for the thruster, etc.; (2) those that their effective period are mainly determined by the executive instructions of valves and subsidiarily determined by the flight program.