A joint team from the US Air Force Research Laboratory and the Pentagon's DARPA division are working on the next generation of military transporter, hoping that the hypersonic fleet of the future might be able to carry equipment around the globe at speeds of up to Mach 5.
The aim of the latest development programme is to have a hypersonic craft ready for service by 2023. A previous hypersonic test in 2013 dropped the X-51A vehicle from a plane at 50,000 feet, then accelerated it up to Mach 4.8 in 26 seconds -- making it perhaps a little uncomfortable for human fliers. There'd be complimentary peanuts everywhere.
The test craft was demonstrating the possibilities of a scram jet engine, an engine that only begins to work properly once already accelerated up to a high enough speed to force the air into the thing.
Air Force Chief Scientist Mica Endsley explained how the plan is now to incorporate the scram engine into a vehicle that can take the power, saying: "What they are trying to do now is build the whole system so that it is not just about the engine. You have to have materials that can operate at the kind of temperatures you have when you are going at hypersonic speeds. You have to have guidance systems that will function when you are going at those types of speeds. There are a bunch of technological challenges that have to be addressed to make a functioning system that will work."
And of course, there will be an accompanying Air Force hypersonic weapons program, to make sure whoever's the boss of the US at the time can point at a map and have it promptly annihilated from a safe distance by a warhead travelling at up to Mach 10. [Military]