Chemical engines
Internal-combustion and rocket engines burn fuels for high power density and familiar logistics.
Propulsion is the shared problem every vehicle solves differently — convert stored energy into controlled motion without leaving the certified envelope.
Electric drivetrains
Motors plus batteries or catenary trade tankers for grids and quieter cabins.
Lift & thrust
Wings, rotors, keels and wheels turn raw force into the motion the route actually needs.
Transmission paths
Gears, shafts, props and ducts decide how much energy arrives as useful work.
Control loops
Throttles, fly-by-wire and autonomy sit on top of propulsion — they do not replace physics.