STS109-E-5249 (4 March 2002) --- In Columbia's cargo bay, astronaut John M. Grunsfeld (foreground), payload commander, signals to a crewmate inside the crew cabin. He had just raised his helmet visor's sun shield. Astronauts Grunsfeld and Richard M. Linnehan (out of frame), mission specialist, participating in the first of their assigned STS-109 space walks to perform work on the Hubble Space Telescope (HST), went on to replace the giant telescope�s starboard solar array. Their seven-hour space walk ended at 7:38 a.m. (CST) or 13:38 GMT March 4, 2002.