ACOUSTIC LOADS Acoustic noise results from the propagation of sound pressure waves through air or other media. During the launch of a rocket, such noise is generated by the release of high velocity engine exhaust, by the resonant motion of internal engine components and by the aerodynamic flow field associated with high speed vehicle movement through the atmosphere.

The fluctuating pressures associated with acoustic energy can cause vibration of structural components over a broad frequency band, ranging from about 20 Hz to 10,000 Hz. Such high frequency vibration can lead to rapid structural fatigue. Thus, the objective of a spacecraft acoustic loads testing is to ensure structural integrity of the vehicle and its components.