For the last few years, scientists have been puzzling over the EmDrive, initially designed by Roger Sawyer. It sounds like science fiction: the EmDrive is a propellant-less propulsion system, which works by forcing micro waves through a cone, pretty much.
Basically, it works like this. A magnetron forces microwaves through a closed cone and back towards the small end of said cone. The resulting force creates momentum and, so far, a small amount of thrust. There have been tests on the EmDrive in the past, but it was initially received with skepticism.
Early tests did display a small amount of thrust, but not enough to be thought useful. Subsequent tests, like those being performed at NASA’s Eagleworks Laboratory, have found that it does, in fact, work. We just don’t know how.
So far, the EmDrive flies in the face of physics, pretty much by it’s very existence. This is why it sounds like science fiction: if it were to work at a large enough scale it would make space flight a lot easier because you wouldn’t have to take fuel with you, which would save space, money, and weight in spacecraft, all of which are at a premium.
NASA has yet to release a peer-reviewed paper on their findings, but that’s in the works. In the meantime, we’re relying on information presented by NASA on one of their forums, without images or any real sources to back that up.
This isn’t to say that NASA isn’t telling the truth about the EmDrive, but publishing in the scientific community requires a lot of steps that most people aren’t concerned with, and while that’s good, it makes telling people about cool science take a while.
NASA has also stated that they have more tests in mind, and are developing analytic tools to help figure out what exactly is going on with this drive. The more they can learn about how it works, the better they could, hypothetically, make a system that is actually usable.