Identical Twins, One in Space, One on Earth Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email NASA Expedition 45/46 Commander, Astronaut Scott Kelly along with his brother, former Astronaut Mark Kelly at the Johnson Space Center, Houston Texas speak to news media outlets on Jan.19, 2015. ( NASA/Robert Markowitz / Wikimedia Commons ) Produced by Kristen Meinzer Hosted by Todd Zwillich Produced by PRI and WNYC