We could reach Mars in 70 days, without fuel!

A new fuel-free engine, which was supposedly impossible to create, could soon become a reality. A leaked NASA paper surfaced online indicating that a group of scientists may have invented the controversial EmDrive prototype.The EmDrive is an altogether new approach to engine design, which does not expel any type of gas to provide thrust. Instead the movement is created by ‘ electromagnetic resonation within a closed cavity’. It involves plenty of science and the concept is not easy to understand, but suffice to say it could revolutionize the way we think of any kind of propulsion.

The paper was first leaked on 5 November on a NASA spaceflight enthusiast forum by an Australian EmDrive fan called Phil Wilson, who goes by the username ‘The Traveller’. However, it was taken down by Spaceflight’s moderators, as the paper has not been officially released. It is scheduled to be published by the American Institute of Aeronautics and Astronautics (AIAA) sometime in December.

But, what is an EM Drive?

Designed in 2001 by aerospace engineer Roger Shawyer, the EmDrive is undoubtedly a mystery. The technology made headlines as it offered the possibility of a fuel-free propulsion system, one that could reach Mars in just 70 days as opposed to about 300 days using current rocket engines. Sans fuel, an aircraft could be substantially lighter and could move towards its destination in significantly greater speeds.

However the system exhibits one primary conundrum--it goes against Newton’s third law of motion that states, ‘For every action, there is an equal and opposite reaction.’ In real life, if you push against a wall, your body moves in the opposite direction; after a falling ball strikes the ground it bounces upward, and so on. But here, the EmDrive doesn’t burn any fuel and expel fast moving gases that traditionally result in propulsion in rocket engines. Instead it functions by bouncing microwave photons back and forth inside a closed conical metal chamber. This motion causes the narrow-end of the EmDrive to generate thrust, which could move an attached spacecraft forward. The paper concludes that after error measurements had been accounted for, the EmDrive generates a force of 1.2 millinewtons per kilowatt in a vacuum. Compare this to the force that another type of high-thrust engine--the Hall Thruster--produces, which is 60 millinewtons per kilowatt. While the thrust from the EmDrive is clearly an order of magnitude smaller, researchers say its ability to function without consuming any fuel could more than compensate for its drop in power. In the words of the scientists who wrote the leaked paper, “…for missions with very large delta-v requirements, having a propellant consumption rate of zero could offset the higher power requirements.”

If this prototype ever turns into reality, it may just lead to super-fast--and practical--interplanetary travel.