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 .
