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.
As with airplanes and many other self-powered machines, the fuel a shuttle engine requires can weigh nearly as much as the object it’s propelling, increasing costs while significantly limiting range. It’s a challenge we’re going to need to overcome before launching long-distance treks through space, where carrying enough fuel may not currently be possible. One proposed method for getting future spacecrafts to their destinations is by utilizing a device called a microwave thruster. A British scientist named Roger Shawyer managed to build a similar engine called an EmDrive several years ago, and while a Chinese team also accomplished the same, the rest of the world hasn’t paid much attention until NASA confirmed from its own research that such a device could work during a presentation earlier this week. NASA’s device, a microwave thruster called the “Cannae Drive,” was built by US scientist Guido Fetta. It works by bouncing around microwaves within a sealed container, using a method that seemingly contradicts the law of conservation of momentum. Miraculously, the thruster seemed to function as described, and while the model NASA tested is hardly capable of moving any large object through space, the fact that it registered any measurable movement is promising. If the agency can scale up the device significantly, it could be used for anything from limited satellite propulsion that uses solar power exclusively to a spacecraft that can carry astronauts from Earth to Mars in just a few weeks.