垂直返回重复使用运载火箭技术分析

结合SpaceX公司近期进行的多次猎鹰火箭一子级垂直着陆返回技术试验，对比分析垂直返回重复使用运载火箭两种返回方式的工程应用价值。首先，建立运载火箭一子级动力返回段弹道设计动力学模型。随后，提出基于H-V飞行剖面分段返回弹道设计方法。然后针对“返回原场”（RTLS）和“不返回原场”(NRTLS)两种垂直返回方式，构建综合考虑上升段与返回段的推进剂耦合作用的一体化弹道优化设计策略。最后，通过数值仿真，对比分析了两种返回方式下的火箭运载能力。结果表明，采用“不返回原场”方式的运载能力损失仅占“返回原场”方式的一半，具有较好的工程应用价值。

Analysis of Vertical Landing Technique in Reusable Launch Vehicle

Based on the vertical ascent and descent technique tests by the SpaceX corporation, the application value of two types of descent methods for launch vehicles is compared and analyzed. To this end, the first stage dynamics model of the launch vehicle is formulated for return trajectory. Then, a H-V profile based sectional return trajectory design method is proposed, and considering the propellant coupling effect of the ascent phase and the descent phase, an integrated trajectory optimization design strategy is synthesized for two vertical return ways including return to the launch site (RTLS) and not return to the launch site (NRTLS). Finally, numerical simulation is given to compare the launch capacity of two descent methods, and it is concluded that the NRTLS method costs less launch capacity and shows better practicability.