Hypersonic flight is flight through the atmosphere below about 90 km at speeds ranging between Mach 5-10, a speed where dissociation of air begins to become significant and high heat loads exist.

What is the difference between supersonic and hypersonic?

Hypersonic is, obviously, supersonic on steroids. But while "supersonic" has the clear cut definition of being faster than the speed of sound (Mach 1), hypersonic is a little fuzzier. ... The Air Force and NASA's two record flights can be used to extrapolate what even higher speeds might look like.

How is hypersonic flight possible?

Special materials that can withstand the extreme heat created around Mach 5, and a host of other technologies, are making hypersonic flight in the Earth's atmosphere possible.