NASA Eagleworks made the announcement quite unassumingly via NASASpaceFlight.com. There’s also a major discussion going on about the engine and the physics that drives it at the site’s forum.
The EM drive is controversial in that it appears to violate conventional physics and the law of conservation of momentum; the engine, invented by British scientist Roger Sawyer, converts electric power to thrust without the need for any propellant by bouncing microwaves within a closed container. So, with no expulsion of propellant, there’s nothing to balance the change in the spacecraft’s momentum during acceleration. Hence the skepticism. But as stated by NASA Eagleworks scientist Harold White:
he trouble with this theory, however, is that it might not work in a closed vacuum. After last year’s tests of the engine, which weren’t performed in a vacuum, skeptics argued that the measured thrust was attributable to environmental conditions external to the drive, such as natural thermal convection currents arising from microwave heating.
The recent experiment, however, addressed this concern head-on, while also demonstrating the engine’s potential to work in space.
After consistent reports of thrust measurements from EM Drive experiments in the US, UK, and China – at thrust levels several thousand times in excess of a photon rocket, and now under hard vacuum conditions – the question of where the thrust is coming from deserves serious inquiry.
Serious inquiry, indeed. It’s crucial now that these tests be analyzed, replicated, and confirmed elsewhere. A peer-review and formal paper would also seem to be in order lest we get too carried away with these results. But wow. Just wow.
It’s still early days, but the implications are mind-boggling to say the least. A full-fledged EM drive could be used on everything from satellites working in low Earth orbit, to missions to the Moon, Mars, and the outer solar system.
EM drives could also be used on multi-generation spaceships for interstellar travel. A journey to Alpha Centauri, which is “just” 4.3 light-years away, suddenly wouldn’t be so daunting. An EM drive working under a constant one milli-g acceleration would propel a ship to about 9.4% the speed of light, resulting in a total travel time of 92 years. But that’s without the need for deceleration; should we wish to make a stop at Alpha Centauri, we’d have to add another 38 years to the trip. Not a big deal by any extent of the imagination.