UIT was one of three ultraviolet telescopes on the ASTRO-1 mission flown on the space shuttle Columbia during 2-10 December 1990. The same three instruments were later flown on the space shuttle Endeavour during 3-17 March 1995, as part of the ASTRO-2 mission. Exposures were obtained on 70-mm photographic film in the 1200-3300 Angstrom range using broadband filters and later digitized using a Perkin-Elmer microdensitometer. Image resolution was 3 arcseconds over a 40 minute field of view. Overall, UIT-1 obtained 821 exposures of 66 targets, and UIT-2 obtained 758 images of 193 targets.