The drive supposedly gets its propulsive power by absorbing microwaves. If it works, it would revolutionize space travel and open up the Solar System to exploitation and colonization.
Of course it’s bullshit. If things seem to violate the laws of physics, it’s because they do.
But what if it’s not bullshit?
The gist of EmDrive is that it’s an engine that appears to gain intense amounts of propulsion via ambient microwave energy. Supposedly, this could make for spaceships that can gain speed without propellant in the vacuum of space. If it’s true, then this technology would be a revolution in space—a way to drastically cut down on the mass of spaceships and keep them going by producing continuous thrust, bringing long voyages closer to reality.
In reality, of course, the EmDrive has always been dubious at best. A tenuous connection to NASA has made the idea sound more plausible, but it isn’t. People get starry eyed at the idea of a low-power microwave drive that could propel humanity to the stars and forget the cardinal rule of technology: that if something seems to violate the law of physics, then there’s probably something wrong with the analysis, not the physics.