他说，这是天龙和NASA航天飞机以及欧洲航天局(ESA) Ariana5号火箭的不同之处。因为他们认识到，NASA和ESA的做法需要昂贵的一次性火箭才能将航天器送入轨道。

This, he says, is where Skylon leaves NASA crafts or the European Space Agency's (ESA) Ariane five rocket, in its wake as they need expensive, disposable rockets to propel them into orbit.

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