Two astronauts made NASA's second ever Christmas Eve spacewalk Tuesday in order to repair the International Space Station’s cooling system. Astronauts Rich Mastracchio and Michael Hopkins installed a new ammonia pump to the space station after removing the faulty one on Saturday. “It’s like Christmas morning opening up a little present here,” said Mastracchio as he worked 260 miles above earth. The last time NASA astronauts did a Christmas Eve spacewalk was in 1999, when the Hubble Space Telescope needed repair.
