Imagine a rocket that works without fuel. You pump energy into it and away you go, but there’s no thrust coming out the other side, no exhaust, no waste product and no consumable fuel. It’s the ultimate defiance of Isaac Newton: claiming to have an action without an equal and opposite reaction. First designed in 2001 by aerospace engineer Roger Shawyer, the technology can be summed up as a propellantless propulsion system. Removing the need for fuel makes a craft substantially lighter, and therefore easier to move (and cheaper to make, theoretically). In addition, the hypothetical drive is able to reach extremely high speeds — possibly getting humans to the outer reaches of the solar system in a matter of months.
At Eagleworks laboratory, NASA scientists attempted to test the engine, and in 2016 they published their findings in a peer-reviewed journal. The results? They verified that the EMdrive could work as claimed. If the EMdrive is is a space engine that has an action with no reaction – you pump power into it and get thrust with no discernible exhaust — then this is the largest revolution in physics since Isaac Newton.
Whether it’s new physics and a new type of engine results, or whether it’s simpler than that and the effect’s cause simply hasn’t been determined yet, more and better experiments will be the ultimate arbiter.