Oxygen Harvesting from Eukaryotic Green Algae Cultivation on Moon’s Surface

The presence of oxygen in the Earth atmosphere represents the key resource for the human life. Outside that thin layer of atmosphere, every place is naturally unsuitable for life. Nowadays, the vital resources on board the ISS, the only manned outpost in space, are constantly resupplied directly from Earth in an open-loop cycle. Different strategies must be adopted for deep-space manned explorations in order to ensure the mission independence from Earth. The main idea behind this work is to support the incoming manned mission towards the Moon by recycling part of the emitted carbon dioxide and the urine produced by the human crew to feed a green algae cultivation in a dedicated photobioreactor aimed to close-loop oxygen production. Indeed, oxygen availability opens to a variety of new scenarios for planetary colonization and exploration. A great amount of work on this side has been carried out in the context of MELiSSA Project, whose main objective is to set-up a regenerative life support system to reach the highest degree of autonomy to produce water, food, and oxygen by the mission wastes. Leveraging on the MELiSSA Project experiences and on an ISS photobioreactor demonstrator developed by DRL, we propose to use a Chlorella Vulgaris cultivation in a photobioreactor placed in a space system, properly designed for its survival on the Moon’s surface. In this work we present the basic principle of photosynthesis linked to the hyperparameters that mostly affect the Chlorella Vulgaris cultivation, the set-up of the numerical simulations used for the design of the photobioreactor capable to work in Moon environmental conditions and the preliminary sizing of the system from a thermal and power supply point of view.