Popular Mechanics: Now, Guido Fetta plans to settle the argument about reactionless space drives for once and for all by sending one into space to prove that it really generates thrust without exhaust. by David Hambling
'Fetta is CEO of Cannae Inc, and inventor of the Cannae Drive. His creation is related to the EmDrive first demonstrated by British engineer Roger Shawyer in 2003. Both are closed systems filled with microwaves with no exhaust, yet which the inventors claim do produce thrust. There is no accepted theory of how this might work. Shawyer claims that relativistic effects produce different radiation pressures at the two ends of the drive, leading to a net force. Fetta pursues a similar idea involving Lorentz (electromagnetic) forces. NASA researchers have suggested that the drive is actually pushing against "quantum vacuum virtual plasma" of particles that shift in and out of existence.
'Most physicists believe these far-out systems cannot work and that their potential benefits, such as getting to Mars in ten weeks, are illusory. After all, the law of conservation of momentum says that a rocket cannot accelerate forward without some form of exhaust ejected backwards. Yet the drumbeat goes on. Just last month, Jose Rodal claimed on the NASA Spaceflight forum that a NASA paper, "Measurement of Impulsive Thrust from a Closed Radio Frequency Cavity in Vacuum" has finally been peer-reviewed and accepted for publication by the American Institute of Aeronautics and Astronautics, but this cannot be confirmed yet.'