SM4: Massimino smiles for the camera

S125-E-009232 (17 May 2009) --- Astronaut Mike Massimino, STS-125 mission specialist, is pictured as he peers through a window on the aft flight deck of the Earth-orbiting Space Shuttle Atlantis during the mission's fourth session of extravehicular activity (EVA) as work continues to refurbish and upgrade the Hubble Space Telescope. During the eight-hour, two-minute spacewalk, Massimino and astronaut Michael Good (background), mission specialist, continued repairs and improvements to the Space Telescope Imaging Spectrograph (STIS) that will extend the Hubble's life into the next decade.