When you have an area that's leaking a little more, you get up to a pound a day, maybe a pound a half or even two, then we hit a threshold where, okay, we've got to do something about this. You're always one breath away from having to take shelter somewhere if the station has a problem. It's just a matter of fact of living on board a spaceship.
Astronauts return to ISS after sheltering during air leak repair attempt
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