O(S-1) 557.7 NM AND O(D-1) 630 NM EMISSIONS IN SHUTTLE THRUSTER PLUMES

Radiation resulting from interaction between the effluent cloud of a s pace shuttle thruster and the ambient atmosphere was observed with a s pectrograph aboard the shuttle. The spectral measurements were made be tween 400 and 800 nm with a resolution of 3 nm. The primary emissions are identified as NO2, HNO, O(D-1), and O(S-1). These are the first ob servations of O(S-1) emission in the shuttle plume. These data are com pared with previous measurements, and possible excitation mechanisms a re discussed. The results are also compared with a Monte Carlo simulat ion of thruster plume-atmosphere interaction radiation.