On the development of a launch vibration isolation system

The U. S. Air Force's Phillips Laboratory has sponsored several programs to isolate payloads from mechanical vibrations during launch. This paper details a program called LVIS (for Launch Vibration Isolation System). LVIS' goals are to reduce the RMS accelerations felt by an isolated payload by a factor of 5 compared to an unisolated payload while using minimal launch vehicle services, fitting within existing payload attach fittings' dimension and mass envelopes, and providing fail-safe operation. The LVIS system must provide axial isolation while at the same time not allowing its host spacecraft to ''rattle'' too much and make contact with the launch vehicle's external payload fairing, which is present to protect against heat, aerodynamic, and acoustic loads. This challenging set of goals will be accomplished using an innovative suspension system specially designed to be relatively soft in the vertical and lateral directions and stiff in the rotational directions to prevent payload fairing contact. An overview of the LVIS design and predicted performance is given.