Because long-term spaceflight has known and unknown risks
SpaceX's Dragon splashes down from space with 3,700 lbs of stuff
See the world anew, through the eyes of a long-term space traveler
The end of a year in space
Mark and Scott Kelly are giving scientists a unique look at what space does to the human body
He spent a year in space, but the fun's not over yet
Coverage begins Tuesday at 4:15 PM Eastern
It's the final countdown
And other answers from Scott Kelly’s Tumblr ‘AnswerTime’
No need to call Mark Watney
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