Abstract: The system includes radiation generation and transmission components which radiate tuned microwave electromagnetic energy outwardly from a vehicle through an antenna into a fluid medium through which the vehicle is moving. The microwave radiation is at the frequency of harmonic resonance electromagnetic excitation of the molecules of the medium which produces efficient heating and ionizing of the fluid resulting in a reduction of the mass density thereof. This reduction decreases the drag forces acting on the vehicle resulting in a greatly enhanced aerodynamic and/or hydrodynamic efficiency and also decreases the intensity of the shock waves (which often lead to sonic booms). An aircraft's dramatically higher speed in the surrounding rarefied medium can make it appear to be travelling at "supersonic" speeds.