He is known for his breakthrough physics and popularizing of science, but Dr. Hawking also wanted to fly in space. Erik Viirre led the medical team that helped Stephen experience weightlessness. He says the adventure helped open the possibility of spaceflight for many more people. Planetary Society co-founder Louis Friedman and Society CEO Bill Nye share their memories of the great physicist. Bruce Betts doesn’t let a bad cold get in the way of the What’s Up segment.