基于日、地、月构成的双圆问题(BCP,Bicircular Problem)研究了经过月球旁近的低能地月转移轨道,总结了这些轨道在相空间的分布特点.首先基于BCP模型,利用BCP系统的不变流形,搜索出经过月球旁近的低能地月转移轨道.然后把时间作为非自治系统相空间的增广维度,给出了能够反映出转移轨道在增广相空间分布情况的状态空间图,研究表明转移轨道以族的形式分布于相空间中,并且任意时刻都可以作为此类轨道的出发时刻.最后分析了不同转移轨道族各自速度增量、飞行时间以及系统能量的变化规律,分别得到了速度增量最优轨道族和飞行时间最优轨道族.
The low-energy lunar trajectories with lunar flybys are investigated in the Sun-Earth-Moon bicircular problem (BCP). Accordingly, the characteristics of the distribution of trajectories in the phase space are summarized. To begin with, by using invariant manifolds of the BCP system, the low-energy lunar trajectories with lunar flybys are sought based on the BCP model. Secondly, through the treating time as an augmented dimension in the phase space of nonautonomous system, the state space map that reveals the distribution of these lunar trajectories in the phase space is given. As a result, it is become clear that low-energy lunar trajectories exist in families, and every moment of a Sun-Earth-Moon synodic period can be the departure date. Finally, the changing rule of departure impulse, midcourse impulse at Poincare section, transfer duration, and system energy of different families are analyzed. Consequently, the impulse optimal family and transfer duration optimal family are obtained respectively.