US Section of ISS suffers Ammonia leak: Astronauts evacuated to Russian module

The Expedition 42 crew members of the International Space Station were forced to evacuate the U.S. section Wednesday after a chemical leak, the American and Russian space agencies said.

All crew were safe and had moved to the Russian side of the facility after the leak of “harmful substances,” the Russian Federal Space Agency said on its website.

The U.S. section of the I.S.S. had been sealed off, it said.

NASA confirmed to reporters that the leak was ammonia. The space agency said the crew were safe.

Flight controllers at Mission Control in Houston saw readings that could indicate an ammonia leak in a worst case scenario and acted conservatively to protect the crew.

It is not yet known whether the alarm was triggered by a leak, a faulty sensor or a computer problem, as indicated by a recent podcast.