Mike Massimino served as an astronaut for NASA between 1996 and 2014, going on two Space Shuttle missions to service the Hubble telescope, spending more than 30 hours on spacewalks. He has appeared as himself on The Big Bang Theory and is now a professor at the University of Columbia. Mike is the author of a new memoir Spaceman: An Astronaut's Unlikely Journey to Unlock the Secrets of the Universe.
