hough the ISS recycles as much as possible, it still requires regular shipments of water, oxygen and other supplies from Earth. At around 250 miles altitude, it’s close enough to make regular resupply missions practical. But that won’t always be the case for future space endeavours, such as trips to Mars or a permanent base on the Moon. In such cases, it will be much easier if all the necessities – including air for breathing – can be sourced locally. This is the idea
