五角大楼曾多次表示，空天飞机仅是一个技术“试验床”。

The Pentagon has repeatedly said that the space plane is simply a “test bed” for other technologies.

本文概述了边界层转捩对空天飞机性能的影响。

The leverage on the performance of aerospace plane from boundary layer transition is presented in outline.

在艾森豪·威尔时代，最初的设想是空天飞机，而不是航天飞机。

An alternative to the space shuttle was the original space plane of the Eisenhower era.