However, NASA has finally made an engine that seems to attempt to dislodge the theory, to some extent. The engine was proposed almost 20 years ago, and up to date, it has not been able to make viable.
The engine is made of a cylindrical cone, which is filled with protons similar to microwaves. The energy filled particles bounce around the chamber causing a forward motion.
"Weirdly, the EmDrive doesn't expel anything at all, and that doesn't make sense in light of Newton's third law or another tenet of classical mechanics, the conservation of momentum," said Michael Greshko from National Geographic. "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 works."
The engine also has no exhaust or by product and in essence can be used infinitely without it being exhausted. The engine is said to be so powerful that it would be able to propel a rocket to Mars in 70 days, almost half the number of days mathematically possible at the moment. With all these properties, it is believed that that the engine is, therefore, able to propel through the void of space.
But a group of scientists insists that they have a working prototype that would make all this possible. The team has formally published their experiment.