The breakthrough was built on decades of research into a theoretical propulsion system called an oblique detonation wave engine (ODWE). The concept works by funneling a mixture of air and fuel at hypersonic speeds (more than five times the speed of sound) toward a ramp, which creates a shock wave. This shock wave rapidly heats up the fuel-air mixture and causes it to detonate, blasting exhaust gasses out from the back of the engine at high speed. In theory, this detonation should be able to propel an aircraft at up to 17 times the speed of sound, say the researchers,...
