William Shepherd

William M. Shepherd was a U.S. Navy SEAL officer before joining NASA's astronaut corps. He commanded Expedition 1, launching aboard Soyuz TM-31 in October 2000 alongside Russian cosmonauts Yuri Gidzenko and Sergei Krikalev to become the International Space Station's first resident crew. Shepherd's request that the crew be addressed by the callsign 'Alpha' became an informal nickname for the station in its early years.