Flame spread over solid fuels in a microgravity environment is an important area of research due to its fire safety implications in space crafts. Of all different configurations, flame spread over thin fuels in an opposed-flow environment is the simplest and, therefore, received most attention during the past decade of research. The problem has been studied experimentally and theoretically by different groups of researchers. Recently a theoretical study advanced closed-form formulas for spread rate over thin and thick fuels in the radiativley dominated regime of the microgravity environment. In this work we use a comprehensive computational model to numerically predict the flame spread rates over thin PMMA fuels in different ambient conditions. The results are found

to agree quantitatively with the predictions of the theory as well as exeperimental data accumulated over three years of drop-tower experiments on flame spread over thin PMMA films, further establishing the validity of the flame spread formulas in the microgravity regime proposed by the authors. Flame shapes predicted by the computational model are also found to agree quite well with the interferometer images of the spreading flames in microgravity as well as downward configuration.