An overview of the autonomous navigation for a gravity-assist interplanetary spacecraft

Gravity assist technique plays an important role in deep space missions so that the interplanetary spacecraft can travel to further space with lower energy. A gravity-assist orbit demands accurate navigation in the approach period, helping the explorer achieve orbit insertion and change velocity accurately. The conventional Doppler-Range radio navigation method can hardly satisfy the gravity-assist deep space mission requirement of high performance in accuracy, real time and coverage, while autonomous navigation technology can guarantee the success of gravity assist mission. In this article the principle and mechanics of gravity assist and autonomous navigation is summarized, and the survey of autonomous navigation technology in deep space mission is provided and analyzed. The key technology and the development trends of autonomous navigation are also put forward. The comprehensive analyses can provide reference for development of autonomous navigation technology for spacecraft using gravity assist.