载人登月绕月自由返回轨道与窗口精确快速设计

针对载人登月任务背景及工程约束，提出一种轨道与窗口一体化设计方法。通过两次坐标转化，将自由返回轨道设计参数解耦为近月点独立变量。在双二体假设下，通过4段二体轨道拼接完成自由返回轨道初值快速搜索及匹配近地停泊轨道(LEO)面的月窗口，其结果作为下一步采用序列二次规划（SQP）迭代求解高精度动力学模型轨道参数的初值，在该条精确轨道近月点时刻90 min邻域内产生可以匹配LEO地月转移入轨相位的零窗口轨道。算例表明，该流程能够精确快速地完成具有复杂任务背景及苛刻工程要求的载人登月绕月自由返回轨道与窗口设计问题。

Rapid Design of Circumlunar Free Return High Accuracy Trajectory and Trans Lunar Window for Manned Lunar Landing Mission

A method for manned lunar landing mission trajectory and trans-lunar window integrated design is proposed considering with the task background and project constraints. Through the two coordinate rotations, circumlunar free-return trajectory parameter is decoupled to the independent variables in perilune. Free-return trajectories parameters and window quick search algorithm matching with low earth orbit (LEO) plane are achieved based on 4 stage two-body patched-conic approach under the double two-body model, and the result can be treated as the initial iterative value in the next step, which a free-return trajectory with high precise orbit dynamic model is obtained by sequential quadratic programming (SQP), a free-return trajectory and zero-window approach to LEO phase are gotten from the generation of the 90min neighborhood trajectories. The design example demonstrates the precision and rapidity of the circumlunar free-return trajectory and trans-lunar window approach with complex task background and rigorous project constraints for manned lunar landing mission.