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Final NASA Eagleworks Paper Confirms Promising EM Drive Results (hacked.com)
An anonymous reader quotes a report from Hacked: Earlier this month Hacked reported that a draft version of the much expected EmDrive paper by the NASA Eagleworks team, had been leaked. Now, the final version of the paper has been published. The NASA Eagleworks paper, titled "Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum," has been published online as an open access "article in advance" in the American Institute of Aeronautics and Astronautics (AIAA)'s Journal of Propulsion and Power, a prestigious peer-reviewed journal. The paper will appear in the December print issue of the journal. The final version of the paper is very similar to the leaked draft. In particular, the NASA scientists confirm the promising experimental results: "Thrust data from forward, reverse, and null suggested that the system was consistently performing at 1.2 +/- 0.1 mNkW, which was very close to the average impulsive performance measured in air. A number of error sources were considered and discussed." The scientists add that, though the test campaign was not focused on optimizing performance and was more an exercise in existence proof, it is still useful to put the observed thrust-to-power figure of 1.2 mN/kW in context. "[For] missions with very large delta-v requirements, having a propellant consumption rate of zero could offset the higher power requirements. The 1.2 mN/kW performance parameter is over two orders of magnitude higher than other forms of 'zero propellant' propulsion, such as light sails, laser propulsion, and photon rockets having thrust-to-power levels in the 3.33--6.67 uN/kW (or 0.0033--0.0067 mN/kW) range."
In other words, a modest thrust without having to carry fuel can be better, especially for long-distance space missions, than a higher thrust at the cost of having to carry bulky and heavy propellant reserves, and the EmDrive performs much better than the other "zero propellant" propulsion systems studied to date.
Now, does it work? No idea, frankly. I'm more inclined to believe the results of, you know, an actual test than someone who didn't do the test but insists it can't work in spite of the test....
It's difficult to convey to a non-physicist just how accurately and consistently quantum field theory describes nature. Physicists routinely make calculations which have lower uncertainly than the best experiments. For example the anomalous magnetic moment (https://en.wikipedia.org/wiki/Anomalous_magnetic_dipole_moment) is in agreement with theory to ten significant figures.
Physicists tend to be fairly cautious describing results, but when it comes to basic theory at energies up to a few hundred GeV we are confident that we have *all* physical effects well and truly nailed. This doesn't mean that we can always solve the equations perfectly: quantum mechanics is hard, but the equations themselves are almost beyond reproach.
It's not undeserved hubris: it's trillions of independent experiments, billions of dollars and hundreds of thousands of man-years working on the theory by lots of very smart people. The theory, quantum field theory (QFT), is simple, consistent and universal. It describes everything we can see around us, with the exception of gravity.
If you ask an actual physicist what he or she thinks of the EM drive, they will overwhelmingly say that is is highly likely there is an unresolved source of error because violation of moment conservation has never been observed and is inconsistent with QFT.