S125-E-007216 (14 May 2009) --- Astronauts John Grunsfeld (left) and Andrew Feustel, perched alone on the end of the Space Shuttle Atlantis? remote manipulator system, perform the first of five STS-125 spacewalks to perform work on the Hubble Space Telescope, temporarily locked down in the cargo bay of the Earth-orbiting shuttle. The two mission specialists are assigned to two of the remaining four sessions of extravehicular activity.