Oxygen interaction with materials III: Data interpretation via computer simulation

The Evaluation of Oxygen Interaction with Materials III experiment, down by NASA on STS-46, allowed the characterization of the Space Shuttle local en vironment and the products of material erosion by atomic oxygen (AO) by mas s spectrometry. Relatively complex transport mechanisms were involved in th at environment, namely, gasphase collisions and wall reflections. Several s ituations were simulated by a numerical model: quiescent period or thruster operation, orientation of spectrometer to analyze Shuttle environment or e rosion products, and materials directly exposed to ram flux or covered by a baffle. The comparison between numerical and experimental results yielded good agreement. That contributed to the experiment interpretation and the v alidation of the model. It pushed model parameters toward a large AO accomm odation and a small Kapton(R) erosion efficiency at low AO energy.