Rotating Detonation Engines
First developed in the 1950s at the University of Michigan, these rocket engines use powerful and chaotic detonations, self-propagating thanks to hypersonic shockwaves travelling around a ring-shaped combustion chamber, in place of slower, more controllable combustion reactions, to create powerful, high efficiency rockets and engines.
Explosions get you much more bang from your fuel buck than combustion – if your engine can withstand them. NASA believes the rotating detonation engine could be the future of deep space travel, and it's getting strong results in prototype testing.
A Florida team working with the US Air Force says that it's built and tested an experimental model of a rotating detonation rocket engine, which uses a spinning series of chaotic explosions inside a ring channel to create super-efficient thrust.
The U.S. Navy is examining the potential of using Rotating Detonation Engines (RDEs) to improve fuel consumption and cut costs.