STS-125 MS1 Good and MS4 Massimino during EVA4

S125-E-008633 (17 May 2009) --- Astronauts Michael Good (left) and Mike Massimino, both STS-125 mission specialists, participate in 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 Good continued repairs and improvements to the Space Telescope Imaging Spectrograph (STIS) that will extend the Hubble?s life into the next decade.