Interplanetary travel could be a step closer after scientists confirmed that an electromagnetic propulsion drive, which is fast enough to get to the Moon in four hours, actually works.
The EM Drive was developed by British inventor Roger Shawyer nearly 15 years ago but was ridiculed at the time as scientifically impossible.
It produces thrust by using solar power to generate multiple microwaves that move back and forth in an enclosed chamber. This means that until something fails or wears down, theoretically the engine could keep running forever without the need for rocket fuel.
The drive, which has been likened to Star Trek's Impulse Drive in the Starship Enterprise, has left scientists scratching their heads because it defies one of the fundamental concepts of physics - the conservation of momentum - which states that if something is propelled forward, something must be pushed in the opposite direction. So the forces inside the chamber should cancel each other out.