CAPE CANAVERAL, Fla. -- Space station astronauts repaired a crippled cooling system during a rare Christmas Eve spacewalk Tuesday, braving a "mini blizzard" of noxious ammonia as they popped in a new pump.
It was the second spacewalk in four days for U.S. astronauts Rick Mastracchio and Michael Hopkins, and only the second Christmas Eve spacewalk ever.
NASA ordered up the spacewalks to revive a critical cooling loop at the International Space Station. All nonessential equipment had to be turned off when the line conked out Dec.