Acoustic Simulation of Spacecraft Flight Vibration Environment

A reverberant acoustic field is frequently used in ground testing when it is desired to generate a spacecraft vibration environment similar to that encountered in flight. The sound-pressure level specified to accomplish this is usually the same as the maximum expected flight fluctuating pressure level. Experience has shown this to be an inadequate way to specify reverberant ground test levels because of basic differences in the characteristics of the reverberant and flight fluctuating pressure fields. This paper reviews pertinent information on this subject that has recently been obtained from large upperstage space vehicles.