据报导,美国私营空间大蓬车公司在1986年提出了以7.5亿美元研制“空间大蓬车”航天飞机计划,提出者认为这是航天飞机的第3个黄金时代。“空间大蓬车”是一个多次使用的两级发射系统,它与单人驾驶的轨道器或一个不载人延迟回收级、一个有翼单人驾驶返回助推器、一个类似潜水艇的发射船、一个轨道“车站”以及轨道转移飞行器结合组 According to the report, the U.S. private space caravan company proposed in 1986 a program of space shuttle development for “$ 750 million space shuttle”, which the authors consider as the third golden age of space shuttle. The space caravan is a multi-purpose two-stage launch system that is used with a single-pilot orbiter or an unmanned delayed recovery stage, a winged single-boomerang booster, a submarine-like Launch ship, a rail “station” and a combination of orbiting vehicles