The more I read about the upcoming Shuttle mission, the cooler it sounds. The official goal of the mission is to perform routine maintenance and repairs on the Hubble Space Telescope, but nothing about the flight is routine — there will be five spacewalks, each lasting over six hours, and when finished, the Hubble will have entirely new solar arrays. It’ll also have a new camera (with over 10 times the resolving power as the old one), a new cooling system to revive the long-dormant infrared camera, and a new power unit. That last one is the cause of the greatest complexity; in order to replace the old unit, the Hubble will have to be powered completely down, for the first time ever. (Quietly, engineers are holding their breath, hoping that the telescope powers back up without incident.)