A fast oxygen atom source has been used to study the velocity dependence of O atom infrared excitation reactions with various molecular species in a crossed beam experiment. These short wave infrared (SWIR) measurements are performed under single collision conditions, simulating the low Earth orbit environment. Such data are fundamental to the analysis and interpretation of the atmospheric oxygen atom interaction with plume exhaust species and with the local environment about structures in low Earth orbit. Measurements have been performed over the oxygen atom velocity range of 6 to 12 km/s. These are the first such experimental measurements, and they may be used to validate theoretical estimates presently used in predictive models. We specifically discuss the velocity dependent cross sections for the reaction O + N2 → NO(v) + N. This reaction is endothermic for O atom velocities ≤ 8 km/s. Preliminary data are also shown for the reaction O + CO2 → CO2(&ngr;3) + O → CO(v) + O2. Both band integral and spectrally resolved results will be presented. The spectrally resolved data provide information on the rotation/vibrational distribution of the excited states. Limited observations of infrared emissions resulting from atmospheric interactions have become available in recent years from both shuttle- and rocket-borne experiments. Comparisons between our experimental database and selected data from several different flight experiments are provided. These comparisons clearly identify the kinetic mechanisms responsible for the flight observations. ¿ American Geophysical Union 1994