Expedition 22 was the twenty-second long duration crew flight to the International Space Station (ISS). This expedition began on 1 December 2009 when the Expedition 21 crew departed. For a period of three weeks, there were only two crew members; it was the first time that had occurred since STS-114. Commander Jeff Williams and flight engineer Maksim Surayev were joined by the rest of their crew on 22 December 2009, making the Expedition 22 a crew of five.[1]
The expedition had ended when Soyuz TMA-16 undocked on 18 March 2010, and was immediately followed by the start of Expedition 23.