When Roger Shawyer first unveiled his EmDrive thruster back around 2003, the scientific community laughed at him. They said it was impossible, that it was based on a flawed concept, and couldn’t work because it goes against the laws of conservation of momentum. But somehow, despite all of the reasons it shouldn’t work, it does. Scientists at NASA just confirmed it. Shawyers engine provides thrust by “bouncing microwaves around in a closed chamber.” That’s it. There’s no need for a propellant of any kind like rocket fuel. When filled with resonating microwaves, the conical chamber of the thruster experiences a net thrust toward the wide end. These microwaves can be generated using electricity, which can be provided by solar energy. In theory, this means that the thruster can work forever, or at least until its hardware fails.