SamuraiBlue
Captain
It's actually called a detonation rocket engine harnesting the shockwave to propel the vehicle instead of the expanding exhaust.
Japan’s space agency JAXA that is has successfully demonstrated the operation of a “rotary detonation engine” in space, a world’s first.
Such an engine uses a series of controlled explosions that travel around a circular channel at its base. The result is a massive amount of thrust coming from a much smaller engine using significantly less fuel — a potential game changer for deep space exploration, according to JAXA.