基于大幅值Lyapunov轨道的地月转移轨道设计研究

基于平面圆形限制性三体问题模型，利用与绕月轨道相切的大幅值Lyapunov周期轨道，提出了一种新的地月转移轨道设计方法。根据Poincaré截面与限制性三体问题动力学系统对称性计算得到的大幅值Lyapunov轨道，通过与绕月轨道拼接，将地月转移问题转化为地球到大幅值Lyapunov轨道的转移问题。为保证探测器能够从近地轨道（LEO）切向逃逸到达大幅值Lyapunov轨道，通过计算其稳定流形，采用最近点作为Poincaré截面的终止条件求解探测器的初始状态，并根据初始状态完成地月轨道的设计。仿真结果表明，该地月转移策略相比于Hohmann转移，在同样只需要两次速度增量的前提下，约节约100 m/s的速度增量，该研究为地月转移轨道的设计提供了一种新思路。

Research on Earth-Moon Transfer by Using a Large Amplitude Lyapunov Orbit

A method is described for constructing a new type of low energy transfer trajectory from the Earth to the Moon by utilizing a large amplitude Lyapunov orbit which is tangential to the lunar orbit. In order to find the specific Lyapunov orbit, a simple numerical method is investigated by analyzing the states in the Poincaré map. After achieving the patch of the lunar orbit and the large amplitude Lyapunov orbit, the Earth-Moon transfer problem can be transformed into that of transferring to the Lyapunov orbit from the Earth. In order to guarantee the spacecraft can escape from the low Earth orbit (LEO) tangentially, the periapsis map is introduced to determine the spacecraft's initial states when calculating the stable manifolds, and then Earth-Moon transfer is accomplished from these initial states. Numerical simulations demonstrate that compared with the classical Hohmann transfer, this new transfer strategy needs approximately 100 m/s less fuel consumption and provides a new way of thinking for low energy Earth-Moon transfer.