Air Force astronaut
Col. Michael Good, an astronaut on mission STS-125, participates in the mission’s fourth session of extravehicular activity May 17, 2009, as work continues to refurbish and upgrade the Hubble Space Telescope. During the eight-hour, two-minute spacewalk, Colonel Good continued repairs and improvements to the Space Telescope Imaging Spectrograph that will extend the Hubble’s life into the next decade. (Courtesy photo)