If there’s one major priority in space, it’s making sure you’ve got enough oxygen available. A close second is recycling – not just packaging and so forth, but ‘human by-products’ as well. The crew of the ISS are about to start killing two birds with one stone as they install a device prosaically named the Oxygen Generation System, which is designed to make breathable air from purified urine. Brings a whole new meaning to ‘atmosphere leak’.