Shuttle Orbiter acoustic fatigue certification testing

Abstract

The Space Shuttle Orbiter is designed to a unique combination of loads and environments not previously encountered in aerospace practice because the reusable Shuttle is launched like an expendable space vehicle and the Orbiter lands horizontally like a conventional aircraft for the specified 100 mission-life of the Orbiter. The Orbiter is subjected to structural vibration caused by engine exhaust-generated acoustic noise during liftoff and aerodynamic noise during atmospheric flight. A requirement was established to certify the Orbiter structure, Thermal Protection Subsystem (TPS), mechanisms, equipment, etc. and to gather empirical data to support fatigue analyses and update vibration and internal noise criteria before the completion of the Orbiter flight test program (OFT). The requirement has largely been satisfied by completing a comprehensive acoustic fatigue development and certification test program. This paper addresses the certification portion of the program including test article selection, objectives, results, and conclusions. Also included are comparisons of ground and flight test data.