Listen as Second Opinion Live speaks with guest Dr. Michael Barratt — physician, astronaut, and the man who literally wrote the book on space medicine. Dr. Barratt returned to Earth in October, 2009, after 200 days on board the International Space Station. Plus, hosts Dr. Matt Birnholz and Dr. Michael Greenberg debate the latest mammogram guidelines, whether heart disease is the real "Curse of the Mummy," and more.