自从苏联在1957年10月4日发射第一颗人造卫星以来,美、苏等国不惜花费大量美元和卢布来研制一次使用的运载火箭,并把仪器和宇航员送入高空。美国到1978年底已经发射了839枚运载火箭。到1977年底,世界各国已用1807枚运载火箭把各种不同的有效载荷送到地球轨道和外层空间。但是,没有一枚运载火箭可以再次使用。美国的航天飞机即将研制成功,苏、法等国也开始进行研制。这种情况会使这些国家对一 Since the Soviet Union launched the first satellite on October 4, 1957, the United States and the Soviet Union and other countries spent so much dollars and rubles to develop a used launch vehicle and to send instruments and astronauts into the air. The United States has already launched 839 launch vehicles by the end of 1978. By the end of 1977, various countries in the world had sent various payloads to Earth orbit and outer space with 1807 launch vehicles. However, none of the launch vehicle can be used again. The space shuttle of the United States is about to be successfully developed and the countries such as the Soviet Union and France also started to carry out research and development. This situation will make these countries one