This paper is concerned with the transfer trajectory design among multiple planets using multiple flybys. The proposed trajectory design method consists of a semi-analytical tuning strategy and iterative patched-conic method. The tuning strategy refers to a method realizing the smooth connection between a hyperbolic trajectory near a planet and a trajectory obtained by Lambert's problem between the planet and another one. The proposed method iteratively solves Lambert's problem and the tuning strategy so that the arrival or departure velocity obtained by Lambert's problem coincides with the velocity at the corresponding point in the sphere of influence (SOI), assigned by the tuning strategy. Consequently, a smooth and continuous trajectory with multiple flybys can be obtained, where the SOI of each flyby planet and the flyby time are explicitly taken into account. Moreover, analytical conditions with respect to the orbital elements of the arrival and departure hyperbolas are provided to minimize velocity mismatch at the periapsis of a flyby planet. Through numerical simulation using the Cassini example, it is shown that the resultant trajectory by the proposed method is close to the optimal trajectory obtained by the n-body problem. Thus, a suitable approximate trajectory can be effectively generated without solving the n-body problem.

本文涉及使用多个飞越的多个行星之间的转移轨迹设计。所提出的轨迹设计方法包括半解析调整策略和迭代补锥方法。调整策略指的是一种实现行星附近的双曲线轨迹与由行星和另一行星之间的兰伯特问题获得的轨迹之间的平滑连接的方法。所提出的方法迭代地解决了兰伯特问题和调整策略，从而使兰伯特问题获得的到达或离开速度与调整策略指定的影响范围（SOI）对应点处的速度一致。因此，可以获得具有多次飞越的平滑且连续的轨迹，其中明确考虑了每个飞越星球的SOI和飞越时间。而且，提供了关于到达和离开双曲线的轨道元素的分析条件，以使飞越行星的根尖处的速度失配最小化。通过用卡西尼算例进行数值模拟，结果表明，所提出的方法所产生的轨迹接近于所得到的最优轨迹。n身体问题。因此，可以在不解决n-体问题的情况下有效地产生合适的近似轨迹。