NASA is planning an emergency spacewalk to repair an ammonia leak on the International Space Station. The spacewalk would occur Saturday, the agency says.
"Following Thursday's identification of an ammonia coolant leak outside the International Space Station, the Expedition 35 crew Friday began preparing for a possible spacewalk Saturday," according to an email from the agency. "A final decision on whether to go forward with a spacewalk is not expected until late [Friday]."
If approved, American astronauts Chris Cassidy and Tom Marshburn would conduct the spacewalk. They have each done three spacewalks in the past.
Astronauts on the station noticed the leak on Thursday. Ammonia is used to cool power systems on the station. According to the agency, the leak could shut down cooling systems on the station within 48 hours if not plugged. For now, the station continues to operate normally.