多体系における低推力推進式宇宙機の重力アシスト軌道の自動設計

我们已经实现了一个自动化的方法，在多体动力学系统的小推力轨迹的设计。我们的方法进行了测试和演示，以帮助设计两个未来的JAXA任务：命运和立方体卫星使命计划于2018年推出的EQUULEUES。我们希望我们的方法将继续作为一个重要的工具，使命规划，并有助于在空间exploration.The搜索的名义轨迹为DESTINY是在增量步骤的时间在地球上和目标小行星法厄同的时代开始的弹道轨迹具有较高的相对速度。然后在小推力优化工具GALLOP中对初始猜测进行优化，并将其相对速度降低到小于1.5 km/s，以满足使命要求。权衡研究自动进行与GALLOP解决新的优化问题，在不同的地球发射日期和法厄同飞越日期。这有助于我们探索轨道远地点和近地点距离的权衡，这对航天器的动力需求有重要影响。为了进行EQUULEUS的使命分析，提出了一种在地月系统中生成一组良好转移轨道的系统方法，包括5个主要步骤：前向传播、准晕轨道的计算、后向传播、前向腿和后向腿的匹配以及解的细化。这些步骤统一在一个工具箱中，便于使用和灵活更新。因此，设计过程可以以几乎自动的方式完成，只有少数用户的干预。

We have implemented an automatic approach for the design of low-thrust trajectories in multi-body dynamical systems. Our method is tested and demonstrated to aid the design of two future JAXA missions: DESTINY and a CubeSats mission scheduled to be launched in 2018-EQUULEUES. We expect our method will continue to serve as an important tool for mission planning and contribute in space exploration.The search for the nominal trajectory for DESTINY is made in incremental steps of time on the Earth and the target asteroid-Phaethon's epoch starting from a ballistic trajectory with a high relative velocity. The initial guesses are then optimized in a low-thrust optimization tool-GALLOP and lowering its relative velocity to less than 1.5 km/s for the mission requirement. Trade-offs studies are performed automatically with GALLOP by solving new optimization problems at different Earth launch dates and Phaethon flyby dates. That can help us explore the trade-off of the trajectory's apogee and perigee distance, which have a significant impact on the spacecraft's power requirement.For the mission analysis of EQUULEUS, a systematic method of generating a good set of transfer orbits in the Earth-Moon system is developed, which involves 5 main steps: forward propagation, computation of quasi-halo orbits, backward propagation, matching of forward and backward legs, and refinement of solutions. These steps are unified in a single toolbox for the ease of use and flexibility for updates. The design process can thus be done in a nearly automatic fashion with only a few user's interventions.