“For every action there is an equal and opposite reaction.” So says Newton’s Third Law of Thermodynamics. The principle is fundamental to space travel, as the combustion of propellant exhausted from the rear of the spacecraft imparts forward motion. But what if a rocket could be designed without reliance on Newton’s Third Law, and could travel through space without the weight penalty of a large fuel load for long flights? Is such a vehicle impossible?
First proposed by British inventor Richard Sawyer in 1999, the Electromagnetic Drive – or EmDrive – consists of a cone-shaped engine in which microwaves bounce back and forth inside. The microwaves are produced with electricity which, in turn, could be provided by solar panels for space travel. Since there is no obvious source of thrust, the device has been received with great skepticism.
Skeptics must now contend with a peer-reviewed paper by Harold White, leading some scientists at NASA’s Eagleworks Laboratory to believe that the thrustless engine really works. White’s experiments addressed critics’ contention that a source of Third Law thrust could be generated by the engine heating up and warming surrounding air. The experiment: test the engine in a vacuum, of course, where there is no air to warm. Sure enough, the experiments proved that thrust was possible without the warmed air effect. Next Step: test the EmDrive in space.
White’s experiments don’t address how the EmDrive works in apparent violation of Newton’s Third Law, and peer review only indicates that White’s research methods are defensible, without actually proving the EmDrive would work in the real world. But if the device can be proven further, it opens the possibility of fuel-less travel to Mars through the vacuum of space in 70 days instead of 6 months.