NASA's 'impossible' EM Drive works: German researcher confirms (2015)

It's another one of those phenomenon that's so near the noise threshold that it's hard to measure reliably. They get forces around 70 μN. This is very small, and although they have a balance sensitive enough to measure it, there are lots of effects which can produce tiny forces like that.

The experimental work described in the paper is disappointing, in that the original cavity system apparently had a Q of something like 100,000, but their system only has a Q of 50, because it's mistuned for the microwave oven magnetron they're using. ("Unfortunately, the absorption peak at the resonance we were aiming at was smaller then expected (probably also due to misalignments after soldering).") The highest thrust reported by anybody with this is 720 mN, but that was in air. They're almost four orders of magnitude below that, in vacuum. For reference, the ion thrusters on the Dawn spacecraft deliver 90mN.

If they had hardware that generated 720mN in air, and tried that in hard vacuum, that would be useful. (In air, all sorts of things, such as heating or electrostatic repulsion, can generate air movement and thus tiny amounts of thrust. So results in air are not too interesting.)

[1] http://moscow.sci-hub.bz/ded43880657f12f27fc596f46abbbfe6/10...

http://forum.nasaspaceflight.com/index.php?topic=38577.msg14...

Wondering why didn't NASA send a EMDrive to space already and just see if it works or not on real conditions instead of testing it on a laboratory?

> The EM drive is so thrilling because it yields enormous amounts of propulsion

Yet IFL-Science says:

> What it actually does is produce a tiny, tiny amount of thrust via a method that’s not entirely understood.

I know which one I trust.. Can this be down voted for not been factual.?

It's not really worth paying attention to claims that someone built one other than perhaps as entertainment value.

  Best way to test the engine is for Elon Musk to make one and send it up on his rocket if it works then he can bring his timeline for mars down a few years.