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.