International Space Station International Space Station International Space Station International Space Station International Space Station International Space Station International Space Station STORY HIGHLIGHTS (CNN) — Two International Space Station crew members will head out Saturday morning for a spacewalk to address an ammonia leak in the orbiter’s cooling system, an emergency that forced NASA officials to work round-the-clock to hatch a plan. First detected early Thursday morning, the leak was causing ammonia to enter space — which could be seen in the form of “flakes of snow” — at a rate of 5 pounds per day, said Mike Suffredini, NASA’s space station program manager Continue reading →