Expedition 12 was a two-person long-duration mission aboard the International Space Station. William McArthur and Valeri Tokarev launched on Soyuz TMA-7 from Baikonur on October 1, 2005, arrived at the ISS two days later, and took over station operations from Expedition 11. The crew maintained the station, supported research and Progress cargo operations, relocated Soyuz TMA-7 between docking ports, and performed two EVAs to service external equipment and prepare the station for later assembly work. McArthur and Tokarev returned aboard Soyuz TMA-7 on April 8, 2006.