Scott Kelly spent a year on board the International Space Station. During that time, his identical twin brother Mark — who's also an astronaut — was on Earth. Since then, scientists have been watching how differently the two have aged. Kelly's now retired, but that doesn’t mean he’s taking it easy. He wrote a memoir about his year in space called Endurance, and has become an advocate for improving science and math education in the US. On this episode of "Success! How I Did It," host Rich Feloni talks with Kelly about what he saw in space, what he missed back on earth, and how he went from a kid who couldn’t focus to one of the most famous astronauts of our time.