But how does nasa plan to get the scramjet to the supersonic speeds necessary for sustained flight ?

不过，太空署要如何使得超燃冲压发动机进入持续飞行需要的超音速呢？

Once a scramjet is moving fast enough , the jet engine would take over and propel it spaceward .

一旦冲压发动机的运动速度足够快，喷射引擎将接手并将之推动进入太空。

Achieving that speed is possible thanks to the craft 's specialized rocket engine , a hypersonic scramjet .

如此快的飞行速度可能要归功于飞机特制的火箭引擎，一种超音速高压喷射装置。

A scramjet is a type of jet engine that uses compressed air in place of conventional turbines to create thrust .

超音速燃烧冲压喷气发动机是利用压缩空气替代常用的涡轮，形成推力的一种喷气发动机。

Until now , however , there are not any practical aircrafts using scramjets as the propulsion engines because of the great technical difficulty of the scramjet .

但是由于超燃冲压发动机技术上的巨大难度，使得至今没有一种使用超燃冲压发动机为推进动力的飞行器投入使用。