The refining reliability modeling method for the satellite system

For the growing of the request for long life and high reliability, the satellite platform and payload design uses redundant and spare technology to improve the reliability of the satellite system widely. Meanwhile, the mission process of the satellite consists of several phases normally. All these design and mission characteristics cause some more complex features for the satellite reliability model and analysis, such as dynamic sequence, dependent failure, multi states of the mission results and the uncertainty. The traditional method based on the reliability block diagram (RBD) can not satisfy the model and analysis requests well, and it is difficult to assess the satellite life and reliability based on the traditional method. This paper focuses on the above problem and proposes the refining modeling method based on the probabilistic risk assessment (PRA) method, which can synthetically adopt the event tree (ET), fault tree (FT), dynamic fault tree (DFT) and Bayesian networks (BN) to model and analyze the above features. The example given in this paper shows the effectiveness of the proposed method, and this method can be as a reference to model and assess the satellite life and reliability.