Currently for space travel, human life support is provided through so-called physico-chemical technologies that maintain breathable air and clean water, while food is stowed and resupplied. An alternate approach is to use biological technologies, such as plants that remove CO2, while producing O2 and food.
The plants and their associated microbiome can also be used to treat wastewater and the clean transpired water then recycled. The requires that use of controlled environment agriculture, similar to what is being used in greenhouses, plant factories and vertical farms on Earth. NASA developed very likely the first operational vertical farm using multiple levels or electric lamps and hydroponic trays. This system was called the Biomass Production Chamber and operated from 1988 to 2000. NASA-funded research at the University of Wisconsin also patented the concept for using LEDs to grow plants. With high intensity lighting, findings from NASA and other space agencies suggest that at least 20-25 m2 of plants will be required to produce enough O2 for one person, and 40-50 m2 will be to produce enough dietary energy (2500 kcal / person day).
Early missions to the moon and Mars will not be able to initially support large “bioregenerative” systems with plants, and the use of biological approaches will likely follow a sequential development as space outposts size and infrastructure expand. But biological systems will be critical to achieve high levels or autonomy and mass closure for future space travel.
