Astronaut Scott Kelly Hits Spaceflight Milestone

— -- No U.S. astronaut has been away from Earth longer than Scott Kelly, who today became the American astronaut who has lived in space the longest during a single mission.

Kelly spent his 216th consecutive day in space today, surpassing the previous record held by U.S. astronaut Michael Lopez-Alegria who spent 215 days in space as commander of the Expedition 14 crew in 2006.

Earlier this month, Kelly reached his 383rd cumulative day in space, beating astronaut Mike Fincke’s record of 382 cumulative days and cementing him as the American who has spent the most days in orbit.

The 51-year-old astronaut took the first spacewalk of his career Wednesday, lasting seven hours and 16 minutes as he worked on upgrades to the exterior of the International Space Station.

Kelly is set to return to Earth in March after spending a year in space as part of a NASA study to understand the effects of long-term space flight on the mind and body. His results will be compared to his identical twin, former astronaut Mark Kelly, who has remained on Earth.