The EmDrive is a seemingly impossible propulsion device that defies the laws of physics, but that isn't stopping scientists from trying to make it work.
Although organizations such as The Planetary Society tests its experimental solar sail later this month, space travel beyond our solar system and beyond still require traditional rocket technology. But it will still take an estimated 50,000 years to reach Alpha Centauri, our closest neighboring star system, using our most powerful rockets. That might change someday, as researchers at NASA may be making some headway on a theoretical EmDrive that may revolutionize space exploration.
An EmDrive is a theoretical propulsion engine that was first proposed over 20 years ago by a British engineer named Roger Shawyer, who claimed that he built a closed system that could generate thrust. It operates by turning electricity into microwaves and channeling its electromagnetic radiation through a cone-shaped chamber.
The microwaves should exert enough force against the chamber to propel a spacecraft through space. However, the theory doesn’t hold up in real life. There’s a laboratory prototype, but it’s still unclear whether it produces any thrust. If it does, it’s certainly not strong enough to propel a spacecraft.
That might change, as a handful of research teams at NASA claim to have successfully produced thrust with an EmDrive. A breakthrough of this magnitude would normally be cause for celebration. However, the thrust produced by these experiments is so small that it’s difficult to determine if they’re real. Therefore, the race is on to develop an instrument sensitive enough to measure tiny amounts of thrust.
In the meantime, many scientists remain skeptical of the EmDrive will ever work, given that the device would defy the laws of physics. Having microwaves push against the walls of a cone to generate thrust would be a case of all action and no reaction. As one website compared the EmDrive to trying to move a car by pushing on the dashboard. Not even fringe interpretations of quantum mechanics are enough to explain how an EmDrive would work.
“From the theory point of view, no one takes this seriously,” physicist Martin Tajmar told Wired. If the EmDrive is indeed producing thrust, then no one knows where that thrust is coming from. According to Tajmar, the only way to overcome this uncertainty is through further experimentation.
DARPA is also conducting EmDrive experiments to find out if one can work in real life. The rewards of revolutionizing propulsion are too big to ignore. Plus, the organization’s mission is to advance transformational change in the US military while beating rivals to the finish line. It doesn’t want the US to experience another “Sputnik moment.”
But even if the EmDrive remains an impossibility, the highly sensitive instruments being developed to test its validity might help lead to other breakthroughs. So, a device straight out of science fiction might end up advancing science in reality.