Nadia Drake and Michael Greshko in National Geographic:
After years of speculation, a maverick research team at NASA’s Johnson Space Center has reached a milestone that many experts thought was impossible. This week, the team formally published their experimental evidence for an electromagnetic propulsion system that could power a spacecraft through the void—without using any kind of propellant.
According to the team, the electromagnetic drive, or EmDrive, converts electricity into thrust simply by bouncing around microwaves in a closed cavity. In theory, such a lightweight engine could one day send a spacecraft to Mars in just 70 days. (Find out why Elon Musk thinks a million people could live on Mars by the 2060s.)
The long-standing catch is that the EmDrive seemingly defies the laws of classical physics, so even if it’s doing what the team claims, scientists still aren’t sure how the thing actually works. Previous reports about the engine have been met with heaping doses of skepticism, with many physicists relegating the EmDrive to the world of pseudoscience.
Now, though, the latest study has passed a level of scrutiny by independent scientists that suggests the EmDrive really does work. Is this the beginning of a revolution in space travel—or just another false start for the “impossible” spaceship engine?