Verification of the Space Shuttle Ascent Flight Control

Abstract

The Space Shuttle vehicle consists of a reusable Orbiter vehicle, reusable SRB's (solid rocket boosters) that burn in parallel with the Orbiter main engines, and an expendable main propellant tank (external tank).During the critical flight phases such as ascent, primary flight control is provided by four onboard digital computers operating as a redundant set with each computer processing the same sensor data set, solving the same set of flight control algorithms, and independently driving via a digital data bus a secondary servo valve on each hydraulic actuator employed in gimballing the propulsion engines.This paper describes the unique avionics design features associated with Space Shuttle ascent flight control, and the test article, test equipment, and test techniques used to verify the ascent flight control prior to commitment to the first orbital flight test.