The atmospheric trace molecule spectroscopy (ATMOS) instrument obtained solar occultation spectra of the terrestrial atmosphere during the Atmospheric Laboratory for Applications and Science (ATLAS 1) mission of March 26--April 4, 1992. During this time, Ap varied between 11 and 18 while the F10.7 index was near 192. The analyses of the 5.3-μm spectral data to derive nitric oxide densities in the lower thermosphere and mesosphere are described here. The results show that a peak NO density of 1.0¿108 cm-3 occurs at 105¿2.5 km for the latitude range 38¿N-58¿S. The density values are higher than previously reported using UV measurements. These measurements worsen the discrepancy with photochemical models at low latitudes where models already underpredict nitric oxide. ¿ American Geophysical Union 1995