7 Aeronautical engines; engines other than for land vehicles; engines for boats and watercraft; engines for generating thrust in airplanes, spaceships, aeronautical vehicles, astronautical vehicles, rockets not being land vehicles, drones, satellites, hypersonic aircraft, hyperjets, boats and watercraft, and rocket propulsion systems, namely, ion engines, rotating detonation engines, and plasma propulsion engines; engines for military and law enforcement vehicles, not being land vehicles