On a space shuttle, the movable section at the rear of the large vertical tail. The rudder is split to move outwards on both sides. When a returning shuttle re-enters the atmosphere, the rudder controls yaw and breaks the vehicle's speed. Immediately prior to touchdown, the rudder is opened into a wide ‘V’ to act as a brake.
The rudder is controlled by flight-control software until the shuttle's wings are level before touchdown. Then two pairs of rudder pedals, one each for the pilot and commander, are used.
Subjects: Astronomy and Astrophysics.