Abstract: In this paper the soaceeraft stellar-inertial system is briefly reviewed. In order to generate high grade translational and rotational information of the spacecraft, a concept of GPS-INS-STAR optimal integrated navigation system is studied.The problems discussed include system composition, design philosophy ,performance analysis, inertial measurement unit redundancy management techniques and Kalman filter configuration.Computer simulation results show that this approach would lead to an accurate, autonomous, cost-effective and fault-tolerant navigation system.