STS-120 is the 23rd shuttle mission to the International Space Station, and will launch an Italian-built U.S. multi-port module for the station. Air Force Col. Pamela A. Melroy will command the STS-120 mission to take the Node 2 connecting module to the station. Melroy, a veteran shuttle pilot, is the second woman to command a shuttle. Marine Corps Col. George D. Zamka will serve as pilot. The flight's mission specialists will be 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 will be making their first spaceflight. Expedition 15/16 Flight Engineer Clayton Anderson will return to Earth from the space station aboard shuttle mission STS-120. That flight will carry his replacement, Daniel Tani, to the station. Tani will return on shuttle mission STS-122.