自1988年世界上第一架航天飞机哥伦比亚号发射升空以来,人类实现了重复使用航天飞机的理想。但由于运载火箭只能一次性使用,故航天飞机的运输成本比较高。因此减少运输成本,改进航天飞机升空加速级的结构,是当今世界各国宇航界着重研讨的问题。最近美国洛克希德公司的专家们设计了一种新型航天飞机,它与现役的航天飞机有很大 Since the launch of Columbia, the world’s first space shuttle, in 1988, humanity has achieved the ideal of reusing the space shuttle. However, because the launch vehicle can only be used once, the transportation cost of the shuttle is relatively high. Therefore, reducing the transportation cost and improving the structure of the space shuttle’s acceleration stage are the issues that are emphatically discussed by the astronauts in the world today. Recently, Lockheed experts in the United States have designed a new type of space shuttle that is very large in space with active space shuttles.