propulsion system / unit

hydraulic propulsion unit

vernier propulsion system

stored chemical energy propulsion system

astern propulsion

guided missile cruiser nuclear propulsion (CGN)

jet propulsion engine

jet propulsion

multipurpose aircraft carrier (nuclear propulsion) (CVN)

nuclear propulsion submarine

propulsion machinery

spacecraft propulsion

howitzer with auxiliary propulsion

atomic propulsion

diesel propulsion engine

duct propulsion

exhaust propulsion

integrated electric propulsion

jet-propulsion center

orbit insertion propulsion

orbit transfer propulsion

orbit-raising propulsion

propulsion

electromagnetic propulsion

jet-propulsion engine

chemical propulsion kinetic energy weapon

battery coolant unit / battery-coolant unit (BCU)

gear reduction unit / gear-reduction unit

position and navigation unit / position navigation unit (PNU)

pinch (a unit) out of a large unit

fire extinguishing system sprinkler system and fire alarm system

launch coolant system control unit

unit-construction system