Pitch control of the space shuttle training aircraft

A set of shuttle training aircrafts (STAs) are used by NASA to train astronaut pilots to land the space shuttle after returning from orbit. The STA simulates the dynamics of the much larger and heavier space shuttle with the help of some hardware and software modifications. We present a STA controller that tracks the shuttle pitch trajectory. Our control system includes a feedforward controller based on zero phase error tracking control and a fuzzy proportional derivative (PD) feedback controller. Test results on a ground hardware simulator used at the Ellington Field of NASA Johnson Space Center show that the new controller significantly reduces pitch following errors between the shuttle and the STA, when compared to the existing controller.