STS-80 was a Space Shuttle mission flown by Space Shuttle Columbia. The launch was originally scheduled for 31 October 1996, but was delayed to 19 November for several reasons. Likewise, the landing, which was originally scheduled for 5 December, was pushed back to 7 December after bad weather prevented landing for two days. The mission was the longest Shuttle mission ever flown at 17 days, 15 hours, and 53 minutes. Although two spacewalks were planned for the mission, they were both canceled after problems with the airlock hatch prevented astronauts Tom Jones and Tammy Jernigan from exiting the orbiter.

Columbia brought with it two free floating satellites, both of which were on repeat visits to space. Also, a variety of equipment to be tested on two planned spacewalks was part of the payload. These would have been used to prepare for construction of the International Space Station. Included in the Shuttle's payload were

Columbia carried into orbit two satellites that were released and recaptured after some time alone. The first was the Orbiting and Retrievable Far and Extreme Ultraviolet Spectrometer-Shuttle Pallet Satellite II (ORFEUS-SPAS II). The main component of the satellite, the ORFEUS telescope, had two spectrographs, for far and extreme ultraviolet. Another spectrograph, the Interstellar Medium Absorption Profile Spectrograph, was also on board the satellite. Several payloads not relevant to astronomy rounded out the satellite. It performed without problems for its flight, taking 422 observations of almost 150 astronomical bodies, ranging from the moon to extra-galactic stars and a quasar. Being the second flight of ORFEUS-SPAS II allowed for more sensitive equipment, causing it to provide more than twice the data of its initial run.