<title>Overview of the Space Shuttle acceleration environment</title>

Abstract

The Space Shuttle acceleration environment is characterized. The acceleration environment is composed of a residual or quasi-steady component and higher frequency components induced by vehicle structural modes and the operation of onboard machinery. The orbiter structural modes in the 1 - 10 Hz range, are excited by oscillatory and transient disturbances and tend to dominate the energy spectrum of the acceleration environment. A comparison of the acceleration measurements from different space shuttle missions reveals the characteristic signature of the structural modes of the orbiter overlaid with mission specific hardware induced disturbances and their harmonics. Transient accelerations are usually attributed to crew activity and orbiter thruster operations. Crew work and exercise tends to raise the accelerations to the 10-3go(1 milli-g) level. The use of vibration isolation techniques (both active and passive systems) during crew exercise have shown to significantly reduce the acceleration magnitudes.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.