Space station astronauts repaired a crippled cooling system during a rare Christmas Eve spacewalk, braving a “mini blizzard” of noxious ammonia as they put in a new pump.

SPACEWALKING astronauts had to pull out a hammer and pry bar while attaching a big, new tank full of ammonia coolant to the International Space Station yesterday, successfully driving in a stiff bolt after two frustrating hours.

Spacewalking astronauts had to pull out a hammer and pry bar while attaching a big, new tank full of ammonia coolant to the International Space Station today, successfully driving in a stiff bolt after two frustrating hours.