High-accuracy thrust measurements of the EMDrive and elimination of false-positive effects | CEAS Space Journal | Springer Nature Link # High-accuracy thrust measurements of the EMDrive and elimination of false-positive effects - Original Paper - Open access - Published: 27 July 2021 - Volume 14, pages 31–44 (2022) - Cite this article You have full access to this open access article CEAS Space Journal Aims and scope Submit manuscript ## Abstract The EMDrive is a proposed propellantless propulsion concept claiming to be many orders of magnitude more efficient than classical radiation pressure forces. It is based on microwaves, which are injected into a closed tapered cavity, producing a unidirectional thrust with values of at least 1 mN/kW. This was met with high scepticism going against basic conservation laws and classical mechanics. However, several tests and theories appeared in the literature supporting this concept. Measuring a thruster with a significant thermal and mechanical load as well as high electric currents, such as those required to operate a microwave amplifier, can create numerous artefacts that produce false-positive thrust values. After many iterations, we

NASA Team Claims ‘Impossible’ Space Engine Works—Get the Facts | National Geographic A prototype of the EmDrive, as seen in a test chamber at a NASA lab Photograph courtesy AIAA NASA Team Claims ‘Impossible’ Space Engine Works—Get the Facts Scientists just published a paper saying that the controversial EmDrive produces thrust, even though that defies known laws of physics. By Nadia Drake and Michael Greshko Published November 21, 2016 • 8 min read After years of speculation, a maverick research team at NASA’s Johnson Space Center has reached a milestone that many experts thought was impossible. This week, the team formally published their experimental evidence for an electromagnetic propulsion system that could power a spacecraft through the void—without using any kind of propellant. According to the team, the electromagnetic drive, or EmDrive , converts electricity into thrust simply by bouncing around microwaves in a closed cavity. In theory, such a lightweight engine could one day send a spacecraft to Mars in just 70 days. (Find out why Elon Musk thinks a million people could live on Mars by the 2060s .) The long-standing catch is that the EmDrive seemingly defies the laws of classical physics, so even if it’s doing what the team claims, scientists still aren’t sure how the thing actually works. Previous reports about the engine have been met with heaping doses of skepticism, with many physicists relegating the EmDrive to the world of pseudoscience. Now, though, the latest study has passed a level of scrutiny by independent scientists that suggests the EmDrive really does work. Is this the beginning of a revolution in space travel—or just another false start for the “impossible” spaceship engine? What’s an EmDrive? First proposed nearly 20 years ago by British scientist Roger Shawyer, this incarnation of the EmDrive has been developed and tested by engineers at NASA’s Advanced Propulsion Physics Research Laboratory , informally known as Eagleworks. Put simply, t

[1506.00494] Reconciling a Reactionless Propulsive Drive with the First Law of Thermodynamics permanent address: ]817 Sherbrooke St. W., Montreal, Quebec, Canada # Reconciling a Reactionless Propulsive Drive with the First Law of Thermodynamics Andrew J. Higgins andrew.higgins@mcgill.ca [ Department of Mechanical Engineering, McGill University, Montreal, Quebec, Canada H3A-0C3 ###### Abstract A “space drive” is a hypothetical device that generates a propulsive force in free space using an input of power without the need for a reaction mass. Any device that generates photons (e.g., a laser) would qualify as a propellantless “photon rocket,” but the force generated by emitting photons per power input (3.33 $\mu$ N/kW) is too small to be a practical propulsion device. The ability to generate greater force per power input would be highly desirable, but, as demonstrated in this paper, such a device would be able to operate as a perpetual motion machine of the first kind. Since applying a constant force results in a constant acceleration, the kinetic energy of a mass driven by such a device increases quadratically with time, while the energy input increases only linearly with time.