Abstract: To speed up the response time and reduce launch costs， the research of reusable aerospace plane based on combined propulsion is enhanced in many countries. The British hypersonic aerospace plane project Skylon with pre-cooling SABRE engine has made breakthroughs on the propulsion with a wide range of speed. The key technologies of propulsion system of Skylon such as light and efficient air pre-cooler， circulating heat transfer system as well as highly integrated altitude compensating nozzles are presented firstly. Then the various stages of the overall program with different mission objectives are discussed. The discussion mainly focuses on the hypersonic layout design at a high altitude and low density condition， aerodynamic related techniques and thermal protection measures. At last， a comparison with launching costs is carried out and the Skylon performed as the next-generation European aerospace transport system by ESA is expounded.

Key words: Combined propulsion；Aerospace plane；Pre-cooler；Mission planning

摘要： 为进一步加快反应时间、降低发射成本，各国加大了对可重复使用组合动力空天飞机的研发。英国采用预冷组合发动机SABRE的高超声速空天飞机Skylon项目在宽速域组合动力方面已取得突破性进展。本文首先对其动力系统中的关键技术如轻质高效空气预冷器、内循环换热系统以及高度补偿集成喷管进行了介绍；然后分析了面对不同任务需求的各阶段总体方案迭代，重点关注高空低密度条件下的高速布局设计、气动相关问题以及热防护措施；最后对载荷投放成本进行了横向比较，并阐述了欧空局对其作为下一代欧洲空天运输系统的任务规划。

关键词: 组合动力; 空天飞机；空气预冷器；任务规划