月球探测器直接软着陆最优轨道设计

研究月球探测器直接软着陆最优轨道的设计问题。首先根据探测器直接软着陆的特点，提出了有限推力最省燃料的最优轨道设计问题；然后利用有限推力月面软着陆的最优推力控制方向的计算公式，研究了边值条件和计算方法；最后通过直接软着陆最优轨道的算例及结果分析，发现开始制动高度越低越省能量；推力方向可变时比不可变时节省能量；推力大小可变相当于采用了多级制动，对安全定点着陆非常有利。

Optimal Design of Direct Soft-Landing Trajectory of Lunar Prospector

The optimal design and calculation of the direct soft-landing trajectory for Lunar prospector studied in this paper, according to the theory and method of spacecraft orbital dynamics and the optimal control theory, are the basic work and important problem for the Lunar detection engineering. First, the authors proposed the designing process of direct soft - landing trajectory of Lunar prospector and determined designing scheme;Then, some formulas of optimal thrust of soft-landing were derived , the characteristics of the trajectory were presented by simulation and the minimum-fuel soft-landing with limit thrust was studied; The optimization of the dynamic equations including the control parameters shows that when the brake begins, the lower the altitude is, the less the energy consumption is. Changeable thrust direction can save energy than non-changeable thrust direction and the changeable thrust magnitude is equal to multi-step brake. The method in this paper is of very important theoretical significance and reference value for the orbit designation of moon exploration engineering.