The ammonia leak at the International Space Station has been plugged—for now, as astronauts made an emergency spacewalk to replace the ammonia pump, despite the fact that it showed no signs of damage. Though the leak presented no threat to the station crew's safety, NASA wanted to plug it now while they had people in space still in space. The cause of the eruption remains a mystery, however, and Mission Control plans to continue monitoring the station to ensure things are still running smoothly over the next few days and weeks.
