· 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 … 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 …