A special birthday shoutout to NASA's twin spacefarers. Pictured here, on Jan. 19, 2015 Expedition 45/46 Commander, #Astronaut Scott Kelly (stationcdrkelly) with his brother, former Astronaut Mark Kelly at the Johnson Space Center (nasajohnson) to news media outlets about Scott Kelly's 1-year mission aboard the International Space Station (iss). Photographer: Robert Markowitz #NASA #YearInSpace #happybirthday #spaceisrad #spacestation #exploration