STS-48 was a Space Shuttle mission that launched on 12 September 1991, from Kennedy Space Center, Florida. The orbiter was Space Shuttle Discovery. The primary payload was the Upper Atmosphere Research Satellite. The mission landed on 18 September at 12:38 am at Edwards Air Force Base on runway 22. The mission was completed in 81 revolutions of the Earth and traveled 2.2 million miles. The 5 astronauts carried out a number of experiments and deployed several satellites. The total launch mass was 240,062 pounds (108,890 kg) and the landing mass was 192,780 pounds (87,440 kg).