Sergei Korolev was the Soviet chief designer widely regarded as the chief architect of the early Soviet space program.
Korolev led the development of rockets and spacecraft that enabled several Soviet firsts, including Sputnik 1 and the first human spaceflight. He worked within a secretive system, so Soviet public announcements usually referred to him only as the Chief Designer rather than naming him.
His engineering organization developed the R-7 rocket family. The R-7 launched Sputnik 1 and later provided the basis for launch vehicles used by the Vostok and Soyuz spacecraft. Korolev also directed key elements of the early crewed program.
Korolev and rocket designer Valentin Glushko had a difficult professional relationship, and Glushko later led major Soviet launch-vehicle work. Korolev died in January 1966 after surgery. His identity was publicly revealed only after his death, which explains why contemporary Space Race accounts often described him without naming him.