That's the thing I'm not sure of. Did they have CO2 scrubbers on board?or were they constantly flushing out the old air with fresh air? Cause if you have 200 hrs of time with the scrubbers, and 96 he's of air, you'll die of hypoxia. But if you have no scrubber and just constantly flush the air through, then when the air runs out it's much worse. My guess is they have CO2 scrubbers just cause it seems like a much easier way to carry enough breathing gas for that many people for that long. But I'm really guessing.