Ultraviolet Observations of the Upper Atmosphere from Spacelab

Ultraviolet spectrophotometry in the 100–3000 A region is an old, reliable, proven technique used repeatedly and systematically up to now to study the upper atmosphere of the earth and of other planets. Therein, ironically, lies one of the main problems in convincing the scientific community of the usefulness of performing uv spectrophotometry from Spacelab. Have we not done all this before? Should we not think of something really new and exciting to do for such a futuristic experiment as Spacelab? These are but a few of the understandable first reactions of many scientists to the proposal. A second drawback at first glance stems from the common belief that uv spectrophotometry is useful only for the study of the atmosphere above 120 km. altitude while emphasis in Spacelab planning has been on the region below that level. Consequently, it would seem a difficult task indeed to assign a role, if any, to the ultraviolet in the 1980’s.