The method used and results found by the team “ASTL-NUAA” from NUAA for the problem of GTOC 11 are presented in the paper. The problem is mainly decomposed into three parts: multiple targets flyby sequence optimization for the Mother Ships, station-building database construction problem of asteroid transfer arcs, and station-building mission planning. Therefore, a three-step optimization framework is proposed to solve the problem. After analyzing the data of all the asteroids and selecting according to the orbital elements and mass of the asteroids, an asteroid candidate set RS1 is chosen as candidate targets for the Mother Ships. A two-level optimization algorithm based on a genetic principle is applied to solve the two-impulse asteroid flyby problem and rapidly determine the asteroid sequence of each Mother Ship. Subsequently, a method of filtering input data for the time-optimal rendezvous problem by the optimal flight time and the corresponding optimal relative phase is proposed to construct a station-building database with less computation burden. The optimal relative phase is obtained by solving free final-phase continuous low-thrust time-optimal problem. The station-building database is composed of the results of continuous low-thrust time-optimal rendezvous problems. At last, a branch-and-bound algorithm based on the greedy strategy is adopted to rapidly get the result by maximizing the minimal mass among the stations. The final score of our solution is 4315.6663, which is obtained after the competition.

文中介绍了南航“ASTL-NUAA”团队针对 GTOC 11 问题所使用的方法和发现的结果。问题主要分解为三部分：母舰多目标飞越序列优化、小行星转移弧建站数据库建设问题、建站任务规划。因此，提出了一个三步优化框架来解决这个问题。在对所有小行星的数据进行分析后，根据小行星的轨道要素和质量进行选择，选择一个小行星候选集RS1作为母舰的候选目标。应用基于遗传原理的两级优化算法求解双脉冲小行星飞越问题，快速确定每艘母舰的小行星序列。随后，提出了一种通过最优飞行时间和对应的最优相对相位对时间最优交会问题的输入数据进行过滤的方法，以构建计算量较小的建站数据库。通过求解自由终相连续低推力时间最优问题得到最优相对相位。建站数据库由连续低推力时间最优交会问题的结果组成。最后，采用基于贪心策略的分支定界算法，通过最大化站点间的最小质量，快速得到结果。我们的解最终得分是4315.6663，是经过比赛得到的。