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Ammonia Leak Outside Station; Crew in No Danger
At around 10:30 a.m. CDT on Thursday, the Expedition 35 crew reported seeing small white flakes floating away from an area of the International Space Station’s P6 truss structure. The crew used handheld cameras and Mission Control used external television cameras to gain additional imagery in an attempt to narrow down the leak’s location.

› Audio: Commander Hadfield reports ammonia leak to Mission Control Houston (mp3 audio)
› Audio: Capcom Doug Wheelock updates station crew on status of ammonia leak (mp3 audio)

The crew reports, along with imagery and data received by flight controllers in Mission Control in Houston, confirmed that the rate of the ammonia leaking from this section of the cooling system has increased. Ammonia is used to cool the station’s power channels that provide electricity to station systems. Each solar array has its own independent cooling loop. This ammonia loop is the same one that spacewalkers attempted to troubleshoot a leak on during a spacewalk on Nov. 1, 2012. It is not yet known whether this increased ammonia flow is from the same leak, which at the time, was not visible.

The station continues to operate normally otherwise and the crew is in no danger.

Plans are being developed to reroute other power channels to maintain full operation of those and other systems normally controlled by the solar array that is cooled by this loop.

The early analysis by thermal control systems specialists indicates that the leak rate could result in a shutdown of this one cooling loop in about 48 hours. The team is looking at whether any additional imagery is needed to isolate the leak’s location.

› Read more about the station's radiators
› ACTS overview from Boeing

› Read more about Expedition 35
› Read more about Expedition 36