Laboratory simulations of energetic atom interactions occurring in low earth orbit

The Space Shuttle flights provided the first significant data base on the environment experienced by a large space structure operating in LEO. A number of interesting and unanticipated effects were observed, including material erosion induced by ambient oxygen atoms, the visible Shuttle glow occurring above surfaces exposed to the ram flow, and large near-field perturbations and variability in the gaseous neutral and plasma environment about the Shuttle. This paper provides a brief overview of these observations and their phenomenological interpretation, and then discusses laboratory approaches to their investigation. The emphasis is on the state of the art in the development of energetic oxygen atoms sources and the variety of experiments presently being performed with such devices.