关键词: N体问题, DRO轨道, 轨道优化, 弱稳定边界, 庞加莱截面, 月球借力

Abstract:

Deploying the space station on a stable periodic orbit （e.g.， distant retrograde orbits， DROs） in the vicinity of the Moon can significantly reduce the lunar exploration cost， and the space station can also be used as a steppingstone for manned asteroid or mars missions. Reducing fuel consumption is an important issue during construction and cargo resupply of the cislunar station. For transter trajectory from Earth into DRO， DRO insertion cost can be effectively saved with the aid of weak stability Boundary （WSB） transfer， but reading WSB directly requires higher launch velocity. This paper aims at improving the numerical sensitivity of transfer trajectory which leverage Lunar Gravity Assist （LGA） and WSB transfer simnltaneously. The initial guess of trajectories are obtained by “perilune Poincare map” and “v infinity matching” strategies， then multiple shooting with analytic gradient is applied under high fidelity model， better computerational efficiency are obtained by applying improved methods. In numerical simulation， for the DRO with a resonant ratio of 2∶1， for the minimum cost solution， the Earth launching injection is 3.127 km/s （60-70 m/s is reduced compared with directly launching into WSB）. The time of flight is 102.88 d， and DRO insertion maneuver only needs 66.1 m/s.

Key words: N-body problem, Distant Retrograde Orbit （DRO）, trajectory optimization, weak stability boundary, Poincare map, lunar gravity assist