A pair of spacewalking astronauts stepped outside Thursday to begin demanding repair work on the Hubble Space Telescope, a job made all the more dangerous because of the high, debris-ridden orbit. John Grunsfeld and Andrew Feustel emerged from space shuttle Atlantis and quickly got started on their first job, a camera swap. The telescope — the size of a school bus — loomed over them. “Ah, this is fantastic,” Grunsfeld said as he floated out. “Woo-hoo,” Feustel shouted.
