地月空间对称自由返回轨道设计与分析

摘要

为快速设计出适合载人月球探测任务和地月空间人员运输任务的自由返回轨道, 在三体模型下研究了地月空间对称自由返回轨道的设计方法及其轨道特性.首先, 在圆型限制性三体模型建立自由返回轨道地心旋转系下二维极坐标动力学模型.其次, 根据自由返回轨道对称特性建立求解模型, 选择近月点y轴速度为控制变量, 并基于月球逃逸速度给出控制变量初值估计方法, 提出了不同地心和月心运行方向的对称自由返回轨道搜索策略.最后, 分析了4种类型对称自由返回轨道的轨道差异, 并分析了不同近地点高度和近月点高度下自由返回轨道的轨道特性.仿真结果表明:文章提出的设计方法能快速准确地搜索出指定类型的对称自由返回轨道, 同时其轨道特性分析结论可为后续载人月球探测任务和地月空间人员运输任务的自由返回轨道选择提供参考.%In order to quickly design the free-return trajectory suitable for human lunar exploration mission and personnel transport mission in earth-moon space, the design method and orbital characteristics of symmetrical free-return trajectories in earth-moon space are studied in the three-body model.The two-dimensional polar coordinate dynamics model of free-return trajectory in the geocentric rotation system is established based on the circular restricted three-body model, and then according to the symmetric characteristics of the free-return trajectory, the solving model is established, the y-axis velocity in perilune is selected as the control variable, an initial value estimation method of the control variable is proposed based on the lunar escape velocity, and a search strategy for symmetric free-return trajectory with different moving directions in perigee and perilune is proposed.Finally, the orbital differences of four types of symmetrical free-return trajectories are compared, and the orbital characteristics of free-return trajectories with different perigee altitude and perilune altitude are analyzed.The simulation re-sults show that the design method proposed in this paper can quickly and accurately search the specified symmetric free-return trajectories.Meanwhile, the analysis results of orbital characteristics can provide references for selecting free-return trajectories in the following human lunar exploration missions and personnel transport mission in earth-moon space.