#rocket_engine__rocket  a jet engine containing its own propellant and driven by reaction propulsion
  supertype:  jet_engine__jetengine  a gas turbine produces a stream of hot gas that propels a jet plane by reaction propulsion
  part of:  rocket
  subtype:  takeoff_booster__takeoffbooster__booster__booster_rocket__boosterrocket__booster_unit__boosterunit__multistage_rocket__takeoff_rocket__takeoffrocket  the first stage of a multistage rocket
  subtype:  nuclear_rocket__nuclearrocket  a rocket engine in which a nuclear reactor is used to heat a propellant
  subtype:  retrorocket  a small rocket engine on a larger rocket or spacecraft that is fired to slow or alter its course
  subtype:  space_rocket__spacerocket  a rocket powerful enough to travel into outer space
  subtype:  thruster  a small rocket engine that provides the thrust needed to maneuver a spacecraft

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