When airglow measurements are obtained from an orbiting satellite, instruments are typically directed either horizontally or upward in order that the glow may be seen against a nonreflecting background of low brightness. At many wavelengths, the brightest airglow is well below those altitudes at which orbit can be sustained, and so it would be desirable to look downward in many circumstances. The practicability of performing useful observations of airglow near nadir is herein examined by study of digital records from the DMSP visual scanner and comparable records from the VAE instrument on AE-C. When looking downward the background may consist of erratically variable light because surface lights are often bright and the surface, reflecting moonlight and the glow itself, has variable albedo in some regions. The results indicate that on moonless nights, it may be feasible to devise machine algorithms that will isolate portions of the radiance measured near nadir from which the airglow intensity can be determined. These algorithms must discriminate in favor of the darker regions within the field of view and subsequently test for the uniformity of illumination that is expected of airglow from a geographically limited area. Some useful results may even be derived under weak moonlight. This is a provisional estimation because the data available for examination, while they were the best available, were lacking in several important respects.