垂直返回重复使用运载火箭弹道特性分析和优化设计

针对重复使用弹道设计中上升段弹道与返回段弹道之间相互耦合的问题，本文提出一种简化总体弹道优化设计的方法，首先根据影响返回段设计的一子级射程关键约束，进行上升段的弹道设计，经分析在同样的一子级射程约束情况下，上升段存在两组分离点参数，其次分析了在不同的分离点情况下，上升段和返回段在前场和原场两种返回模式下的运载能力损失情况，并对相关弹道特性进行了分析，得出在前场返回情况下优选低弹道方案，原场返回情况下，优选高弹道方案，该结果可为垂直返回重复使用运载火箭的弹道设计提供参考。

Trajectory Analysis and Optimal Design of Vertical Landing Reusable Launch Vehicle

A simplified method in trajectory optimal design is provided for the coupling question of the ascent phase trajectory and the return phase trajectory. Firstly, by taking the key parameters from the ascent phase trajectory design which affected the range of the rocket first stage, the trajectory of ascent phase is designed. There are two different characters on the separation point of the ascent phase trajectory with the same constrain of the range of the first stage. Next, the launch capacity and the trajectory character is analyzed on different separation point, for return to or not to the launch site. The results show that if not return to the launch site, low trajectory is better than high trajectory, and if return to the launch site, high trajectory is better. The analysis results would provide a reference for the trajectory design of vertical landing reusable launch vehicles.