Microalgae for combined air revitalization and biomass production for space applications

Human spaceflight missions require a Life Support System (LSS), to ensure that the required conditions for human survival are met inside the spacecraft. The longer and further the mission, the more important it becomes to recycle from the human-produced waste, to reduce dependence on Earth’s resources. Food production can only be achieved using biological components, which can complement the current existing physicochemical components of LSS, forming a Hybrid Life Support System. Microalgae, like higher plants, are able to produce O₂ and biomass, consuming CO₂ by photosynthesis. Therefore, microalgae can be used both for air revitalization and food production in space missions, thus reducing the required resupply. This chapter reviews the experiments carried out so far, both on Earth and in space, as well as the biological and technical challenges of using microalgae as part of the LSS. Finally, still open questions and future perspectives are discussed.