Chris Hadfield: There are three things on station that are absolutely the most dangerous. One is a fire. Of course we have to react if we have a fire case where the station starts filling up with smoke.
Two is we have a cooling system on the station that uses ammonia and so if ammonia breaks through into the atmosphere inside the station, then that’s extremely hazardous.
And the third case is a depressurization — a micro meteorite or something hits us.
Chris Hadfield on ISS radio: Houston Station, Roman closed node to starboard. It’s set hard closed onto its seal so we think the leak may be in the vestibule and Tom’s just checking our T-REZ (ph).
Female Speaker: Houston copy. We’re looking at our data as well.
Chris Hadfield: And so we have to know the procedures but also practise the procedures here in the simulator in Houston, working together as a crew, understanding our own reactions and understanding how we’re going to react together to solve the problem as best we can. It’s a matter of life or death.