CREATING CLEAN AIR
There’s probably never been a time where clean air has been as important as it is today, with some air purifier makers claiming more than a 50 per cent rise in sales during 2020. But some air-purification technology was first developed to stop space crops from harming astronauts. Back in the 1990s, NASA conducted research into removing the build-up of natural gases emitted from plants, called ethylene. This was important research for establishing the possibility of having plants for food aboard crewed spacecraft during interplanetary travel.
On Earth ethylene is harmless, but in an enclosed spacecraft it can build up and cause health issues for astronauts. Engineers created ethylene ‘scrubbers’ to take the gas out of the air and convert it into useful by-products. The process works by drawing the air surrounding the plants into tubes coated with titanium dioxide. When a UV light is passed over the titanium dioxide, the ethylene in the air is converted into water and carbon dioxide, which can be reused to maintain the plant’s growth. Following its development, this technology has been widely adapted to remove particles, bacteria, viruses and mould from the air.
Mizuna lettuce growing aboard the ISS.