"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."
https://www.nationalgeographic.com/science/article/nasa-impossible-emdrive-physics-peer-review-space-science
"The NASA Eagleworks Laboratory team even put forward a hypothesis for how the EM Drive could produce thrust – something that seems impossible according to our current understanding of the laws of physics.
In case you've missed the hype, the EM Drive, or Electromagnetic Drive, is a propulsion system first proposed by British inventor Roger Shawyer back in 1999.
Instead of using heavy, inefficient rocket fuel, it bounces microwaves back and forth inside a cone-shaped metal cavity to generate thrust.
According to Shawyer's calculations, the EM Drive could be so efficient that it could power us to Mars in just 70 days."
https://www.sciencealert.com/it-s-official-nasa-s-peer-reviewed-em-drive-paper-has-finally-been-published
"It has been argued that the electromagnetic drive – a rocket engine that drives through electromagnetic waves – can eliminate fuels needed to travel deep underground. In this EM drive, microwaves trapped within the conical cavity generate thrust from microwaves that are trapped there. This invention is championed by inventor Roger Shawyer."
https://www.eclipseaviation.com/is-nasa-testing-the-em-drive-in-space-yet/
"Shawyer says that these features are all consistent with the electromagnetic drive, or EmDrive, which he developed, and which, despite considerable controversy and misleading reports of its demise, is still very much under development by DARPA.
Depending on which theory you follow, the EmDrive uses an obscure piece of physics to seemingly generate thrust from a closed system. The results have apparently repeated at independent labs around the world including NASA’s Eagleworks and researchers at Xi’an in China. While existing versions only produce tiny amounts of thrust, comparable to ion drives used on satellites and space probes, Shawyer calculates that a version based on superconductors could drive a high-speed demonstration vehicle.
Skeptics, of course, claim that this is all bunk: that the EmDrive violates the laws of physics, can never generate thrust, and any experimental results to the contrary are lab errors, wishful thinking, or simply fraud."
https://www.forbes.com/sites/davidhambling/2021/06/29/ufos-could-be-us-military-craft-says-electromagnetic-drive-inventor/?sh=55d1df354e19