ISS Crew Retreats to Russian Segment After Potentially Hazardous Leak

New media are reporting that an ammonia leak has prompted US astronauts to retreat to the Russian segment of the International Space Station.

Update: NASA has made the following statement. Original story from Russian media is below

The Expedition 42 crew members are safe and in good shape inside the Russian segment of the International Space Station following an alarm in the U.S. segment at about 4 a.m. EST.

Flight controllers in Mission Control at NASA’s Johnson Space Center in Houston saw an increase in pressure in the station’s water loop for thermal control system B then later saw a cabin pressure increase that could be indicative of an ammonia leak in the worst case scenario. Acting conservatively to protect for the worst case scenario, the crew was directed to isolate themselves in the Russian segment while the teams are evaluating the situation. Non-essential equipment in the U.S. segment of the station was also powered down per the procedures.

In an exchange at 7:02 a.m. with Expedition 42 Commander Barry Wilmore of NASA, spacecraft communicator James Kelly said flight controllers were analyzing their data but said it is not yet known if the alarm was actually triggered by a leak or whether the situation was caused by a faulty sensor or by a problem in a computer relay box that sends data and commands to various systems on the station.

From the Moscow Times:

The U.S. segment of the International Space Station (ISS) has been evacuated and sealed off from the rest of the station after indications of a hazardous chemical leak were discovered, a senior NASA official said Wednesday.

Sean Fuller, NASA’s top representative in Russia, told The Moscow Times by phone that the U.S. and European crew living in the U.S. side of ISS had taken refuge in the Russian segment after a possible ammonia leak was detected.

Ammonia is a highly toxic substance used in the cooling systems of spacecraft and space stations.

Fuller said NASA had not yet conclusively confirmed the ammonia contamination on board the $150 billion orbiting outpost, but that the crew is following procedure to isolate a possible danger zone.

A statement from the Russian space agency, Roscosmos, on Wednesday said the entire 6-man international crew is in the Russian segment of the space station, which has been sealed off from the U.S. side after signs of a leak were detected at 11.44 a.m. Moscow time.

“The crew’s safety has been achieved through the coordinated and expedient actions of the cosmonauts and astronauts, as well as the mission control teams in Moscow and in Houston,” the head of the Russian mission control center in Moscow, Maxim Matyushin was quoted as saying in the Roscosmos statement.

The atmosphere in the Russian segment shows no sign of ammonia contamination, both sides said. According to Fuller, the crew’s immediate task is to verify the existence of the leak.