Manufacturing machines and machine tools for the cutting and forming of materials; motors and engines, except for land vehicles; electrical drives for machines, namely, drives for motors; electric propulsion mechanisms for space vehicles, namely, electric engines for propelling space vehicles in space, not for land vehicles; spacecraft engines in the nature of propulsion engines for spacecrafts, namely, ion thrusters, not for land vehicles; high-voltage generators; ion implanters, namely, mac...