Vibration, Shock, and Acoustic Noise Associated with Space Vehicles

Analysis of telemetered vibration data received from Transit-Courier launchings, using Able-Star space vehicle equipment, indicates three major sources of vibration. These are missile engine acoustic noise at liftoff, aerodynamic effects as the missile reaches Mach 1, and separation shock when the second-stage vehicle is launched. These measurements were taken at the Able-Star instrument platform; thus very little vibration if any was induced by turbopumps, alternators, or snap-operating valves. Vibration decreases to extremely low levels between the three periods of major excitation; therefore, transmission of vibration directly from the rocket engine through the missile structure has negligible effect on space vehicle equipment. Data obtained are useful in establishing equipment environmental test criteria. Specifications requiring sinusoidal combined with random vibration are indicated by some functions and shaped random, emphasizing certain frequency regions, are suggested for other functions.