Trajectory Analysis and Design for Relay Satellite at Lagrange L2 Point of Earth-Moon System

The Earth-Moon L2 point plays a significant role in the far-side lunar landing mission due to its special location. Orbits about the L2 point could provide continuous communications link between the Earth and the lunar far-side lander. Transfer trajectories using lunar gravity assisted to L2 point and libration point trajectories are studied in this paper. Considering mission requirements,the trajectory characteristics and influence factors are analyzed,including launch window,transfer duration,amplitude of halo orbit,attitude and inclination of periselene. Through the analysis of influence factors,the paper provides several conclusions of trajectory characteristics,which could offer references for relay satellite trajectory design and optimization.