It appears to use dark matter for propulsion. I.e. the low energy, sub-atomic soup of the universe which is not coalesced into an atom. Clarification: Like objects in a swimming pool the weight of an object is measured relative to the medium but the medium itself is not observed or factored.
In the EM drive the microwaves likely energize the dark matter imparting electrical polarization which creates pressure -i.e. thrust.
Considering 3/4s of observable mass is composed of dark matter it’s unlikely the EM drive would work in a true vacuum. But even outer space isn’t a true vacuum. If they could increase the energy of the microwaves a couple million times they might be on to something.
“Considering 3/4s of observable mass is composed of dark matter“
Except it isn’t.
L