col. hadfield: they do not behave the way you would expect. [video clip] ♪ col. erage person on earth uses 350 liters of water a day over 1400 cups of water. water consumption is critical on earth and even more so on the international space station where we have a closed environment. from washing ourselves to making coffee, the water that is expelled is collected in a purification system. we reclaim about 93% of all the water. we even recycle our urine. >> ewww. col. hadfield: before you cringe at the thought of drinking left over urine the water we end up with is pure than more of the water you drink at home. that makes the international space station its own self-contained environment. a critical step towards living long periods off planet earth. brian: how long does it take you to get used to drinking urine? col. hadfield: we all drink reprocessed urine every day. dinosaurs were here for millions of years, and all the water on earth passed through a dinosaur's kidneys at some point. the real question is, do you have a good vacation system? -- purification syste

col. hadfield: very little.billion of us and you set some really tight requirements and constrictions and then you filter a whole bunch of people that do apply and you choose a teeny tiny representative sample of humanity. and that's filter whether it is , japanese, chinese, european, canadian american it tends to , spit out the same sort of person. the language is different. if you are russian, it is a cosmonaut. if you are french, it is a --, but once you get all of us in a room, we have a lot more to talk about than you might think. brian: how different is the russian space program from the american space program? col. hadfield: the american program and the russian program really set the standard for the world from the beginning with sputnik in 1957 and the early american unmanned and the race to the moon. it set the whole tone of it and white space agencies should look like. and, they have a lot of similarities. it is a complex thing that requires a huge amount of infrastructure. the time it takes is longer

col. hadfield: more than you think. each piece had to come up in a rocket or the back of the space shuttle. each rocket and each space shuttle limits the size of that particular piece. the russian pieces are built in moscow and shipped to kazakhstan. so the limit to their pieces is the height of the railway overpass and length of railcars. they have several modules. nasa has several modules. europeans have one big module. japanese have a couple modules. canada has the big robot arm on top. if you looked at it, it would feel like you are in a 12 bedroom house. not 12 bedrooms. 12-room building. maybe barnes or trailers bolted together. brian: do you stay in your own area? col. hadfield: the station is an international space station. you stay in the area where your work is, but your work could take you anywhere in the station on any given day. and often, you will be working a , suite of experiments and may spend 80% of your week in the japanese laboratory because that is where your experiments are, but you could be anywhe