A study of fault tree analysis for control program in space system

This paper proposes a Fault Tree Analysis (FTA) method for control program (CP) for space systems. Once a serious fault occurs in CP, a space system is lost. To avoid such situation, methods that can clarify its causes and propose its countermeasure are required. The concepts of proposed FTA methods are followings: preparing Fault Tree (FT) templates corresponding to primitive statements in CP, defining FTA procedure, and defining CP rewrite method that makes it easier to conduct FTA. The proposed method is helpful to conduct FTA. As a result of applying the proposed FTA method to the fault that a spinning satellite rotates too fast, we confirm that the proposed method can clarify the causes of the fault.