· Valery Vladimirovich Polyakov was a Russian cosmonaut who holds the record for the longest single spaceflight in history. Polyakov had an early interest in spaceflight, and in 1971 he … The longest manned flight was by Russian doctor Valeriy Poliyakov (b. ), who was launched to the Mir space station aboard Soyuz TM18 on and landed in Soyuz TM20 on 22 …