地球-火星的燃料最省小推力转移轨道的设计与优化

小推力转移轨道的设计与优化一直是深空探测轨道设计方面的难点。针对这些问题，提出了一种基于等高线图的初始发射机会搜索方法，该方法通过绘制探测器一火星距离的等高线图寻找满足任务约束的小推力转移轨道发射机会；同时，本文还给出了一种小推力轨道的直接优化算法，该算法通过将连续的控制变量参数化，把轨道优化问题转化为参数优化问题，然后基于所提搜索方法，采用逐次二次规划方法进行求解。数值计算验证了该发射机会初值猜测方法和优化算法的有效性。

Design and Optimization of Earth-Mars Optimal-Fuel Low-Thrust Trajectory

The design and optimization of low-thrust trajectory is the one of significant technologies for interplanetary exploration missions. In this paper, we have presented a search approach for launch opportunity based on contour map, which could provided the close distance information between spacecraft and Mars. According to that, we could find the opportunities satisfied with constraints. Then, based on the search solution for launch opportunity, a direct optimization method was employed to compute the optimal-fuel low-thrust trajectory, in which, a parameter optimization problem was reformulated by discretizing the continued control variables, and the sequential quadratic programming algorithm was used to solved it. The validity of search approach for launch opportunity and optimization method is verified by numerical calculation.