Story on the BBC about a urine recycling system for the ISS - it doesn't have a lot of tech details but a few points seemed odd. It uses distilation which means it needs a centrifuge to simulate gravity. A hand powered reverse osmosis pump on a lifeboat can take water from seawater - wouldn't the same thing be simpler.? Isn't most of your body's water lost in breathing (especially in a dry air conditioned enviroment). MIR (IFIRC) had a gutter system to collect condensation form the walls. What's the oxygen supply on the ISS, MIR also electrolysed liquid waste to generate oxygen (while dumping the hydrogen into space). Recycling drinking water while having to ship compressed oxygen cylinders seems unlikely. Is this just a proof of concept thing for a future longer mission?