posted 12-21-2015 11:26 AM               

First designed in 2001 by aerospace engineer Roger Shawyer, the technology can be summed up as a propellantless propulsion system, meaning the engine doesn’t use fuel to cause a reaction. 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 — we’re talking potentially getting humans to the outer reaches of the solar system in a matter of months.

posted 12-21-2015 11:53 AM               

The problem is that the drive — which is said to create thrust without propellant by bouncing microwaves around inside a chamber — would seem to produce more energy than is put into it, violating the law of conservation of energy. In May, NASA downplayed the research:

While conceptual research into novel propulsion methods by a team at NASA's Johnson Space Center in Houston has created headlines, this is a small effort that has not yet shown any tangible results.