Another one that falls under the “unconventional spacecraft propulsion” category. This one is particularly odd given the backstory of the inventor and the specificity of the application.
Google Patent link for US20060145019A1
Inventor: John Quincy St. Clair
Abstract: A spacecraft having a triangular hull with vertical electrostatic line charges on each corner that produce a horizontal electric field parallel to the sides of the hull. This field, interacting with a plane wave emitted by antennas on the side of the hull, generates a force per volume combining both lift and propulsion.
Looking through the patent, there’s a lot of detail and math there. I want to take it seriously, but alas, this is the same legendary inventor who among other wild inventions, filed a patent application for a “Walking through walls training system”. Seriously.
The patent is abandoned, but that can be for a variety of reasons including that the inventor simply didn’t pay the required maintenance fees to the USPTO.
Being abandoned does not necessarily mean that the invention is not workable. Perhaps someone should try to build one of these to find out. Perhaps someone already did.