Spacewalk needed to fix ammonia leak on International Space Station

Astronauts on the International Space Station are preparing for an unscheduled space walk to fix leaking ammonia, which is used to cool the power panels on the station.

While Canadian astronaut Chris Hadfield, who is currently commanding the station, won’t be one of two people doing the spacewalk, he will be assisting from inside. Astronauts Chris Cassidy and Tom Marshburn are preparing for the walk.

"The crew is not in danger, and the station continues to operate normally otherwise," NASA said in a press release issued Thursday. "Work is underway to reroute power channels to maintain full operation of the systems normally controlled by the solar array that is cooled by the suspect loop."

Crews discovered the leak after they saw small white flakes floating away from the station Thursday, says NASA. Using cameras and data from ground crews, members of the International Space Station were able to determine that the rate of the ammonia leak was increasing.

On Twitter, Hadfield called the situation "serious" on Thursday evening.

Hadfield used his Twitter account to announce the change of plans on Friday morning.