This man has the record for the longest time ever spent in space. On an individual mission, meet Valerie Palyakov, a Russian cosmonaut who's nearly 30-year strong record has proven it possible for humans to survive long durations in space. Valerie volunteered for a 437-day flight aboard the Soviet Miers station, and when he returned to Earth on a Soviet capsule, which is not known for being a gentle ride. This absolute legend refused to help with walking to prove that future Martian explorers could walk after spending a significant amount of time in space. His first words after returning, we can fly to Mars, bought us in a loop.