i really enjoyed that episode. the best one so far.

Me: Good episode. Incredibly suspenseful, even though I still knew everything would turn out ok. There is a device now that divers use for covert missions, because they don't expel bubbles, called a rebreather. Essentially, it recycles what you exhale through a filter so you can... re-breath it. By this time I would imagine a more advanced system could be used for just this situation.

Brian FitzGerald: A rebreather doesn't turn CO2 back into Oxygen. When you breath out you breath out a mixture of Oxygen and CO2. The rebreather has a scrubber that filters out the CO2, the remaining oxygen is mixed with new oxygen and you breath it in, the cycle repeats. The reason that you don't have a big tank with a rebreather is because by recycling the oxygen that a SCUBA system would have wasted as part of the bubbles it can make 10 minutes of oxygen last for 30 minutes. The CO2 is in a scrubber, so no bubbles there either.

On Serenity they do have a system to actually re-cycle the oxygen but they said that both it and the auxiliary life support were messed up by the fire and the engine/power troubles.

I was a bit vague on rebreathers, sorry about that, but I do know how they work, used them many times. There are scrubbers and O2 candles of various sizes that don't need power to run, which I have also used. I mentioned rebreathers because I would imagine the suits could sustain air better and wondered why Mal didn't put one on after everybody left.

From what I saw, Kaylee only showed Mal where the part went, not how to hook it up. He must be more mechanically inclined than we've been led to believe.