INFRARED SPECTRAL MEASUREMENTS (450-2500 CM-1) OF SHUTTLE-INDUCED OPTICAL CONTAMINATION

The first shuttle-based infrared spectral measurements in the region b eyond 800 nm were made during the STS-39 mission. A cryogenic Michelso n interferometer in the CIRRIS-1A payload yielded high quality atmosph eric IR spectra in the earthlimb observing mode. In addition, observat ions in the very high earthlimb and in the bay-to-space mode provided important opportunities to assess optical contamination. These observa tions have revealed spectrally-extended H2O and NO emissions as domina nt in the region 450-2500 cm-1 under quiescent conditions. The viewing conditions, spectral and ''spatial'' (limb scan) distributions, and t emporal behavior of the H2O emissions have resulted in their classific ation as shuttle-induced ''cloud glow'' optical contamination.