美国经过十几年的努力,航天飞机即将投入首次飞行试验。这种可重复使用的航天飞机一旦投入实际使用,将对未来的空间活动产生重大的影响。但航天飞机计划的发展前景究竟如何,却是人们所关心的问题。为了最大限度地发挥航天飞机的潜力,美国航宇局已经制定了今后20年内航天飞机的发展规划。据称,在制定这项发展规划时充分 After more than a decade of hard work in the United States, the space shuttle is about to put its first flight test in place. Once put into practical use, such a reusable space shuttle will have a significant impact on future space activities. However, what is the development prospect of the shuttle program is a matter of concern. In order to maximize the potential of the space shuttle, NASA has developed a space shuttle development plan for the next 20 years. Allegedly, in the development of this development plan fully