Helical engine
The Helical engine is a proposed spacecraft propulsion drive that, like other reactionless drives, would violate the laws of physics. The concept was proposed by David M. Burns, formerly a NASA engineer at the Marshall Space Flight Center in Alabama, in a non-peer-reviewed report published on a NASA server in 2019 describing it as "A new concept for in-space propulsion is proposed in which propellant is not ejected from the engine, but instead is captured to create a nearly infinite specific impulse".