Software Design and Development of Chang'E-1 Fault Diagnosis System

During a mission, detecting failure accurately and implementing countermeasures in time may decide the success of a space mission. Chang’E-1 mission is the first lunar exploration mission of China. The satellite has several different telemetry formats and bit rates. Moreover, the accuracy requirement of orbit control is high and demands real-time handling during contingency or abort operations. In addition, the time duration of the mission is very long, lasting more than a year. All these cause some difficulties in fault detection, judgment and handling in the mission. Therefore, in order to detect faults accurately and duly, determine the failure modes in time, implement countermeasures effectively, and provide warning and trend analysis, software of fault diagnosis system is specifically developed for Chang’E-1 mission. The system adopts plugin software structure and advanced Berkeley DB real-time database. In addition, ice middleware is exploited for message passing between processes. It is also the first time that the failure criterion of the mission is described by extensible markup language (XML), and this well solves the problem of separating failure criterion from program coding. The fault diagnosis system can not only well and truly judge failures with clear criterion, but can also provides trend warnings for failures without clear descriptions, and is very helpful for the personnel who are in charge of fault detection. The advanced technologies applied in the system make it expansible. It can also be used in other space missions.