Kelly spent 340 days in space on his most recent mission, allowing scientists to gather a plethora of data about how the human body behaves during long periods in the extreme space environment.
“This year-in-space mission was a profound challenge for all involved, and it gave me a unique perspective and a lot of time to reflect on what my next step should be on our continued journey to help further our capabilities in space and on Earth,” Kelly*said in a statement an**uncing his retirement.* Read more...