Method for adjusting stiffness and acoustic properties of an externally

Abstract

A technique for reducing the acoustic response of a spacecraft electronics equipment module that is structurally and thermally independent of a core spacecraft structure to which it can be mounted. The module takes the form of a thermal radiation panel on which electronic components are directly mounted. The panel is adjusted in stiffness to reduce its dynamic vibration response to acoustics and launch transients. These adjustments are facilitated by the external mounting of the panel to the core structure, preferably using a statically determinate mount that renders the module even less susceptible to vibration transferred from the core structure. External mounting removes the panel from the primary structure load path, which provides the freedom to adjust the stiffness as desired. The use of smaller than conventional equipment panels renders them less responsive to acoustic vibration because the dimensions of the panels are very much less than the wavelengths of the low-frequency acoustic energy that is of concern when launching the spacecraft. Other steps to minimize the vibration response include adding perforations to the equipment panels, providing an air gap between adjacent panels, adjusting the bending stiffness of the panels to reduce acoustic coupling, and damping the vibrations in the panels.