Eventually, the X-51's hypersonic propulsion technology may be applied to civil aviation as well.

MSN: Hypersonic aircraft taken out for a trial run on B-52 bomber

Woody Norris' HyperSonic Sound, or HSS, is about to hit the mainstream in a very big way.

FORBES: Magazine Article

What was left of the hypersonic engine crashed into the desert 400 km (250 miles) west of Woomera.

BBC: Experimental jet 'a success'

The WaveRider traveled more than 230 miles in six minutes, making it the longest hypersonic flight of its kind.

NPR: Experimental Air Force Aircraft Goes Hypersonic

While the Air Force did not have immediate plans for a successor to the X-51A, it said it will continue hypersonic flight research.

NPR: Experimental Air Force Aircraft Goes Hypersonic

In his hands is his latest invention, the HyperSonic Sound emitter.

FORBES: Now Hear This

If recently announced estimates are to be believed, the hypersonic SpaceLiner that would reduce the journey time from Europe to Australia down to just 90 minutes is about 50 years out.

ENGADGET: Alt-week 2.2.13: SpaceLiners, building a brain and the man made multiverse

It depends on hypersonic gliding maneuvers, the largest supersonic parachute ever deployed, eight hydrazine rocket engines firing in sequence and an elaborate system of tethers called a "sky crane" that are meant to lower the landing craft gently to the ground.

WSJ: NASA's Robot Lab Curiosity Nears Mars