Speaking of resonant cavity devices, state secrets and the EM Drive specifically, there is this: https://www.universetoday.com/143870/x-37b-lands-after-780-days-in-orbit-doing/ It is strongly suggested that a prototype EM Drive was aboard. No comment from officials.
Despite the fact that most scientists still do not think it is feasible, the silence from NASA about the testing in space - is palpable. Let me say again that Logan's geometry would stand a good chance of being superior, if the concept does work, since the area ratio of the surface area of the ends is far greater and that ratio seems to be an important criteria. Instead of say 3:1 it could be 100:1 or more. Using that increased area are might entail providing several different RF frequencies instead of one. Jones
