Until a few years ago, water had to be shipped up to spacestronauts in bags, alongside their food, but a fairly monstrous centrifugal distiller has changed all that, and the result is purified pee that's cleaner than any water you've had in your mouth recently. Good to know we'll be ready to mine for spice on Arrakis when the opportunity presents itself. Hopefully by then the distiller will be a tad smaller. [YouTube]
How Astronauts Turn Pee into Drinking Water