Expedition 20 was the 20th long-duration flight to the International Space Station. The expedition marked the first time a six-member crew inhabited the station. Because each Soyuz-TMA spacecraft could hold only three people, two separate launches were necessary: Soyuz TMA-14 launched on 26 March 2009, and Soyuz TMA-15 followed on 27 May 2009. Soyuz TMA-15 launched from Baikonur Cosmodrome at 10:34 UTC on 27 May 2009. The vehicle docked with the station on 29 May 2009, officially changing the Soyuz TMA-14 crew from Expedition 19 to Expedition 20.