Abstract. As typical safety-critical system, the trustworthiness of spacecraft has become a widespread concern. The evaluation of trustworthiness depends on the execution of spacecraft test cases, of which the adequacy is of great importance for the spacecraft to conduct effective assessment of trustworthiness. This paper focuses on the evaluation of the adequacy of spacecraft test cases based on mutation testing technique. Mutation testing theory is extended to spacecraft testing, and mapping between spacecraft faults and mutation operators is constructed. A virtual spacecraft testing platform is developed, on which the spacecraft fault injection strategy is given and test cases generated by IPOG algorithms are evaluated by adequacy, verifying the effectiveness of the proposed strategy.