中文摘要：

基于改进的Gauss伪谱法，研究了探月返回器跳跃式再入轨迹优化设计问题。首先给出了探月返回器再入轨迹优化问题的三维模型。然后针对探月返回器配平攻角飞行的特点，考虑到实际倾侧角反转机动不可能瞬时完成，对单一控制变量倾侧角的变化范围进行合理限制，并以总吸热量为性能指标，设计了满足过载和驻点热流约束的小升力体大航程跳跃式再入轨迹。最后基于该优化算法，将返回器在各相同初始条件下发生跳跃和不发生跳跃时的最大航程进行比较，并求解得到在不同升阻比和存在不同程度大气密度偏差时不发生跳跃的再入轨迹最大航程和过载峰值，以分析跳跃式轨迹在扩大小升力体再入航程方面的优势。

英文摘要：

The improved Gauss pseudospectral method is used to optimize the skip reentry trajectory for a lunar return vehicle. Firstly, a three degree-of-freedom model of trajectory optimization control problem of the skip reentry trajectory is established. Then, the skip reentry trajectory is designed to meet the constraints such as long distance, overload and the heating rate. Minimization of total absorbed heat is selected as the performance index. During the process of trajectory optimization, the control variable is limited in a reasonable range because of the distinguished features of a fixed-trim reentry vehicle and impossibility of instantaneous bank-angle reversal maneurers. Finally, the maximum flight range is computed by using the pseudospectral method in the two different cases with skip reentry and without skip reentry. In addition, to analyze the flight capability of a low-lift vehicle using skip reentry trajectory, the maximum flight range and peak value of overload are computed by considering the lift-drag ratio offset and the atmospheric density offset.