New Test Suggests NASA's "Impossible" EM Drive Will Work In Space

Last year, NASAs advanced propulsion research wing made headlines by announcing the successful test of a physics-defying electromagnetic drive, or EM drive. Now, this futuristic engine, which could in theory propel objects to near-relativistic speeds, has been shown to work inside a space-like vacuum.

The EM drive is controversial in that it appears to violate conventional physics and the law of conservation of momentum; the engine, invented by British scientist Roger Sawyer, converts electric power to thrust without the need for any propellant by bouncing microwaves within a closed container. So, with no expulsion of propellant, theres nothing to balance the change in the spacecrafts momentum during acceleration. Hence the skepticism. But as stated by NASA Eagleworks scientist Harold White:

[T]he EM Drives thrust was due to the Quantum Vacuum (the quantum state with the lowest possible energy) behaving like propellant ions behave in a MagnetoHydroDynamics drive (a method electrifying propellant and then directing it with magnetic fields to push a spacecraft in the opposite direction) for spacecraft propulsion.

Its still early days, but the implications are mind-boggling to say the least. A full-fledged EM drive could be used on everything from satellites working in low Earth orbit, to missions to the Moon, Mars, and the outer solar system.

EM drives could also be used on multi-generation spaceships for interstellar travel. A journey to Alpha Centauri, which is just 4.3 light-years away, suddenly wouldnt be so daunting. An EM drive working under a constant one milli-g acceleration would propel a ship to about 9.4% the speed of light, resulting in a total travel time of 92 years. But thats without the need for deceleration; should we wish to make a stop at Alpha Centauri, wed have to add another 38 years to the trip. Not a big deal by any extent of the imagination.