Internal Effects Model for Spacecraft Modules Perforated by Orbital Debris

Abstract

A model is developed to predict the effect of a perforating orbital debris particle impact on the pressure and temperature within a pressurized habitable spacecraft module. The model is developed such that it sequentially characterizes the phenomena comprising the impact event, beginning with the initial impact on the outer module wall. The model then considers the creation and motion of a debris cloud within the module wall system and the impact of the debris cloud on the inner module wall. The e nal phase of the model is concerned with the creation and motion of the debris cloud that enters the module interior and its effect within the module on module pressure and temperature levels. This characterization is accomplished through the application of elementary shock physics theory and fundamental thermodynamic principles. The predictions of the analytical model are compared with experimental pressure and temperature data from a series of instrumented high-speed impact tests. Several modie cations are made to thebasicmodel to bring its predictions closerin line with theexperimental results. Following the adjustment of several empirical constants, the predictions of the modie ed internal effects model are shown to be in close agreement with the experimental results.