Space Shuttle Orbiter Model / MediumThe Space Shuttle takes off from Earth as a rocket and maneuvers in orbit as a spacecraft. After reentry into Earth's atmosphere it is controlled and brought in to an unpowered landing in the mode of a conventional fixed wing airplane. The Shuttle takes off vertically under the power of three Rocketdyne main propulsion engines, each developing 375,000 lb. thrust, plus two Thiokol solid propellant booster rockets, each producing 2,900,000 lb. thrust,