The Ultraviolet Limb Imaging Experiment (UVLIM) is part of the Air Force Space Test Program's STP-1 shuttle payload. The science objectives of UVLIM are to determine the electron density profile in the F2 region ionosphere and to measure its diurnal and global variation. The UVLIM scientific instruments include an extreme ultraviolet imaging spectrograph and a far ultraviolet 0.25 m scanning grating spectrograph. Dayglow emissions from H, He, N, 0+, 0 and N2 will be measured. The payload is supported during flight by the NASA Hitchhiker carrier which provides a complete real-time link between the UVLIM ground support equipment and the payload. Orbiter maneuvers align the experiment field-of-view with the earth's limb and sweep the line-of-sight vertically to provide limb scans.