Astronauts who have been in space the longest

– Russian cosmonaut Valeri Polyakov holds the record for the longest single spaceflight at 437 days. – 

– American astronaut Scott Kelly spent 340 days on the ISS, studying the effects of long-term space travel. – 

– Peggy Whitson holds the U.S. record for cumulative time in space, with 665 days over multiple missions. – 

– Sergei Krikalev, a Russian cosmonaut, has 803 days in space across six missions. – 

– Gennady Padalka set the world record with 879 days in space across five missions. – 

– Extended space missions help scientists understand physical and psychological impacts on astronauts. – 

– Prolonged time in microgravity affects muscle mass, bone density, and vision. – 

– Space agencies study radiation exposure to develop protective measures for astronauts. – 

– Psychological challenges include isolation and distance from Earth, affecting mental well-being. – 

These records and research are essential for future deep space missions, including to Mars.