Propellant-free thrusters: Company claims major breakthrough BGRNASA Veteran’s Propellantless Propulsion Drive That Physics Says Shouldn’t Work Just Produced Enough Thrust to Overcome Earth’s Gravity The DebriefNASA expert’s propellantless propulsion drive defies Physics Interesting EngineeringFormer NASA Engineer Says He’s Invented a Thruster That Doesn’t Require Propellant Yahoo News UK