During 1974 while analyzing photometer data obtained from the Atmosphere/Explorer-C satellite, a significant brightness enhancement was discovered surrounding the velocity vector of the instrument. This enhancement appeared to be generated as a result of the interaction of the spacecraft with the atmosphere at a relative velocity of 8 km/sec. The enhancement was found to be inversely dependent on altitude and to have a broad spectral characteristic (the range covered was 3371 ¿ to 7320 ¿) with the most intense effect occurring at the longer wavelengths. In this paper we review these earlier findings, and relate them to the observations of similar glows associated with the Space Shuttle. We also discuss glows that have been studied in laboratory experiments and others that have been reported on various rocket flights. We report a significant brightness enhancement associated with the vehicle wake. |