Mike Massimino served as a NASA Astronaut from 1996 until 2014 and flew in space twice: STS-109 on space shuttle Columbia in March 2002 and STS-125 on space shuttle Atlantis in May 2009 - the final two Hubble Space Telescope servicing missions. Mike became the first human to tweet from space, was the last human to work inside of Hubble, and set a team record with his crewmates for the most cumulative spacewalking time in a single space shuttle mission.

Mike has a recurring role as himself on The Big Bang Theory; appears regularly on late night talk shows, news programs, and documentaries; and is a much sought after inspirational speaker. He received his BS from the Columbia University School of Engineering, and his two MS's and Ph.D. from the Massachusetts Institute of Technology (MIT). He currently lives in New York City where he is an engineering professor at Columbia and an advisor at the Intrepid Sea, Air, and Space Museum.