多约束条件下月球南极探测返回窗口设计

针对月球南极探测任务，综合考虑中国地基深空测控系统现状、月球南极地区光照及地球再入终端等约束条件，利用月球反垂点概念，提出一种从环月轨道出发的三级返回窗口搜索策略.其次，提出一种改进多圆锥截线法，将月球非球形摄动加入到区间的轨道外推中，基于二级返回窗口对返回轨道进行了初步设计.给出以月球南极地区Shackleton撞击坑边缘一点为假定落点，于2020年自月球南极地区返回的仿真算例.仿真结果表明：一方面，窗口搜索方法可以有效解决多约束条件下的月球南极返回窗口设计问题；另一方面，改进多圆锥截线法作为一种初始轨道设计方法，可以有效减少再入误差，同时为后续高精度轨道积分提供良好初值.

Design of Launch Window for Lunar South Pole ReturnMission with Multi Restrictions

Aiming at the mission of Lunar south pole exploration, a launch window searching method of three stages is proposed, taking illumination conditions, the status quo of Chinese ground based TT&C systems and the constraint conditions of Earth reentry process into consideration. A return trajectory is calculated by an improved multi conic method, which combines the lunar oblateness correction in trajectories propagation. Furthermore, return trajectory simulations from Lunar south pole are carried out based on an assumed site in Shackleton rim in 2020. Results show that this launch window searching method is effective and accurate. Additionally, the improved multi conic method can reduce the terminal boundary errors effectively.