The engineering is very intriguing.
How far off are humans away from Hypersonic commercial flights?
Hypersonic weapons projects to begin test flights - space - 04 January 2007 - New Scientist Space
Ultrafast missiles designed to strike targets around the globe will be the first technologies to use hypersonic flight...
For decades, researchers have dreamed of building hypersonic aircraft that could whip around the world in just a few hours. But the first fruits of their labour will instead be compact, long-range missiles that can be launched at enemy targets at the same high speeds.
All are based on so-called scramjets (supersonic combustion ramjets), which mix fuel with air and ignite the mixture as it flows through the engine at supersonic speeds. This means the vehicles do not need to carry oxygen to ignite their fuel, as rockets do. And unlike jet plane engines, which use fans to compress air, they use no moving parts – the shape of their air intakes sucks in and compresses air at supersonic speeds.
The engine for the X-51A uses the gas flow system tested in the X-43A and is being built by US firm Pratt and Whitney. That design uses a rectangular intake, which compresses the air and generates a shock wave that pushes the air through the engine vertically.
Around the World in 80 Days,