STS-120 was the 23rd shuttle mission to the International Space Station, and launched an Italian-built U.S. multi-port module for the station.
Retired Air Force Col. Pamela A. Melroy commanded the STS-120 mission which took the Harmony Node 2 connecting module to the station. Melroy, a veteran shuttle pilot, was the second woman to command a shuttle. Marine Corps Col. George D. Zamka served as pilot. The flight's mission specialists were Scott E. Parazynski, Army Col. Douglas H. Wheelock, Stephanie D. Wilson and Paolo A. Nespoli, a European Space Agency astronaut from Italy. Zamka, Wheelock and Nespoli were making their first spaceflight.