There are two kinds of UFOs: the real ones, which use a technology which surpasses even that envisioned by Tesla (created by the Vril Society), and the ones used by the US/Canada/British secret services, which use a small dextrorotatory subquark reactor, and then utilize the power of the Biefeld-Brown effect to navigate.
Those who want to know where the knowledge about mercury gyros came from in relation to the Vril Society are welcome to study the subject further.
A mercury gyro is used to start the implosion of the atom, that is, to go from normal matter to the baryon state, or to ether four (ether three is a meson, ether two is a quark, ether one is a subquark).
Then the entire UFO becomes a gigantic ball lightning object, completely shielded from the terrestrial gravity of the Earth.
The Nazis tried to go beyond Antarctica, that is, beyond the aether shield/barrier which surrounds the flat earth, but they were not able to go further, this prompted one of the top Vril scientists to say, "there is no outer space".
Was this the most secret project of the Vril/Thule societies? No, already by 1936 they knew pretty much the physics of the implosion of the atom.
The most secret undertaking of the Nazis, was, by far, the Kronos Projekt, which was moved to Antarctica after 1941 under the supervision of Rudolf Hess (that is why the entire flight to Scotland charade was offered to the public).