Refined day-of-launch atmospheric flight loads analysis approach

A day-of-launch atmospheric flight loads analysis approach that reduces con servatism by better defining the components of Right loads that have to be treated statistically and those that can be established with measured wind profiles just prior to launch is described. The approach introduces the con cept of removing from measured day-of-launch winds the rapidly varying feat ures and only using the more slowly changing components in the load calcula tions performed just prior to launch. The proposed approach takes advantage of two recent developments. The first development defines the spectral bou ndary, as a function of time, between wind components that can be considere d slowly varying and those that change rapidly and, hence, have to be addre ssed statistically. The second development provides an approach for calcula ting gust loads caused only by the turbulent: components of the winds and, thus, eliminates the need to include these wind components in the load calc ulations performed just prior to launch.