Vibration Engine has vibration modes caused by rotating machinery. Amplitude ñ4g - typically 1-2 g on engines with well balanced pumps Centaur - vibration of booster causes amplification factor through system. Longer interstage length amplifies vibration more. Vibration Vibration table - vibrates on principle planes (x,y,z) Build engine and then look for amplification, e.g., a valve mounted on a line that can flex amplifies vibration.