载人月球极地探测地月转移轨道设计

针对载人月球极地探测任务，采用一种自由返回轨道与三脉冲机动轨道相结合的地月转移轨道方案。关于自由返回轨道部分的设计，建立了基于近月点伪参数的两段拼接模型，采用一种考虑地球扁率修正的改进多圆锥截线法进行求解，仿真结果显示改进的多圆锥截线法具有更高的求解精度，可为精确设计提供更好的初值；关于三脉冲机动轨道部分的设计，基于混合轨道模型，采用特殊点变轨和Lambert算法相结合的方法进行计算，仿真结果显示该方法能够有效地降低速度增量的消耗。最后，通过大量的仿真计算，对轨道的速度增量特性进行了分析。研究结论可为未来载人月球极地探测地月转移轨道方案的设计提供重要参考。

Design of EarthMoon Transfer Orbit for Manned LunarPolar Exploration Missions

An Earth Moon transfer orbit scheme combining free return orbit with three impulse maneuver orbit is adopted for manned lunar polar exploration missions. In terms of the design of the free return phase, a two phase patched model based on pseudo perilune parameters is established and an improved multi conic method considering correction of Earth oblateness is used. Simulation results show the improved multi conic method has a higher accuracy and can provide better initial values for the accurate design. In terms of the design of the three impulse maneuver phase, based on the hybrid orbit model, a method combining maneuvering at special points with Lambert algorithm is proposed for computation. Simulation results show this method can reduce the velocity increment effectively. Finally, with a great deal of simulation the velocity increment characteristics of orbit are analyzed. The research conclusions can provide significant reference for the design of Earth Moon transfer orbit scheme for manned lunar polar exploration missions in the future.