Emergency Return Analysis of Hybrid Traj Ectory Based on One Impulse for Human Lunar Mission

For human earth-moon transfer mission, emergency return trajectories arc key to astronauts' safe return to earth. Emergency return trajectories based on human translunar hybrid trajectory were proposed, considering safety the most important requirement in human earth-moon transfer mission. There arc three emergent return methods, which arc direct return, immediate transfer and steer by the moon, and steer by the moon and return. The characteristics of transfer time and velocity increment of the three emergent return methods were studied. The advantages and disadvantages of the three emergency return methods were analyzed, providing reference for translunar trajectory selection in subsequent human lunar exploration missions.