As it turns out, a few researchers at Eagleworks, a small NASA team of scientists and engineers that tend toward the less plausible theories in life, have given the theory of the EM Drive a go. And the results were better than naught for a first try.
A real EM Drive is a long way off, though
So don’t get your hopes up about having a propulsion system that doesn’t use a traditional fuel source and that’s super efficient. Just yet at least. The theory holds that a small electromagnetic thruster pulses microwaves into a conical cavity that then produces reactionless thrust directly from electricity and which doesn’t require any kind of direct propellant for the reaction. Thus far it’s only been a theory, though a hopeful and plausible one.
Eagleworks just published a peer-reviewed paper that found a consistent thrust-to-power ratio of 1.2±0.1mN/kW in their own recent experiments. That’s far more thrust than they expected, though not nearly enough to be a significant source of movement for future vehicles.
This is a good advancement not because it provides an immediate solution, but because it shows that our ingenuity definitely can pay off. There are plenty of solutions that may not initially make sense that can be further explored, and thus we shouldn’t simply disregard something unless it’s completely far-fetched. Who knows how far we’ll get in actually making a real EM Drive, too.