Just last year, NASA’s innovative propulsion research section made headlines by stating the successful test of a physics-defying electromagnetic drive, or EM drive. Now, this innovative engine, which could in theory push objects to near-relativistic speeds, has been shown to work inside a space-like vacuum. NASA Eagleworks made the statement quite modestly via NASA SpaceFlight.com.
There’s also a key conversation going on about the engine and the physics that drives it at the site’s forum. The EM drive is controversial in that it seems to break up conventional physics and the law of conservation of momentum; the engine, created by British scientist Roger Sawyer, transforms electric power to thrust without the need for any propellant by rebounding microwaves within a sealed container.
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So, with no dismissal of propellant, there’s not anything to balance the variation in the spacecraft’s momentum during acceleration. Hence the doubt. But as indicated by NASA Eagleworks scientist Harold White:
“[T]he EM Drive’s thrust was due to the Quantum Vacuum (the quantum state with the lowest possible energy) behaving like propellant ions behave in a MagnetoHydroDynamics drive (a method electrifying propellant and then directing it with magnetic fields to push a spacecraft in the opposite direction) for spacecraft propulsion.”
The concern with this theory, however, is that it might not work in a sealed vacuum. After last year’s trials of the engine, which weren’t done in a vacuum, skeptics reasoned that the measured thrust was attributable to environmental surroundings external to the drive, such as natural thermal convection currents rising from microwave heating. The new experiment, however, addressed this worry head-on, while also signifying the engine’s potential to work in space.
“The NASASpaceflight.com group has given consideration to whether the experimental measurements of thrust force were the result of an artifact. Despite considerable effort within the NASASpaceflight.com forum to dismiss the reported thrust as an artifact, the EM Drive results have yet to be falsified. 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 investigation, indeed. It’s important now that these tests be considered, simulated, and confirmed elsewhere. A peer-review and proper paper would also seem to be in order lest we get too carried away with these outcomes. But wow. Just wow. It’s still early days, but its uses are mind-boggling to say the least. A developed EM drive could be used on everything from satellites working in low Earth orbit, to tasks to the Moon, Mars, and the outside the solar system.
EM drives could also be used on multi-generation spacecraft for interstellar travel. A voyage to Alpha Centauri, which is “just” 4.3 light-years away, quickly wouldn’t be so intimidating. An EM drive working under a constant one milli-g acceleration would push a ship to about 9.4% the speed of light, causing a total travel time of 92 years. But that’s without the need for checking; should we desire to make a stop at Alpha Centauri, we’d have to add extra 38 years to the journey. Not a huge deal by any degree of the imagination. Learn more here.
Updated version of the previous article.