先前最长的冲压式喷气发动机下极超音速飞行测试，是在2004年由NASA的X-43进行的，速度更快，但只持续了10s。

The longest previous hypersonic scramjet flight test, performed by a NASA X-43 in 2004, was faster, but lasted only about 10 seconds and used less logistically supportable hydrogen fuel.

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它通过一种叫做超音速燃烧冲压式喷气发动机的特殊发动机来实现超音速。

It achieves hypersonic speed using a special sort of engine known as a scramjet.

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