Fungal based biocomposite for habitat structures on the Moon and Mars

Abstract

One of the key capabilities for long term human exploration missions beyond low Earth orbit is a suitable technology for in-situ resource utilization (ISRU). Indigenous or locally cultivated resources lower the mass and volume of payload that needs to be brought from Earth, and as a result decrease the costs. Therefore, an efficient trade-off space has to be created between robotic ISRU systems brought from Earth, and type of materials used in the process to increase the long term mission sustainability. The objective of the current study is to investigate the production process and feasibility of fungal based biocomposite material for habitat structures on the Moon and Mars, using automated additive construction technology. Previous studies have shown that certain types of fungi are able to survive in extreme environmental conditions. Experiments with γ-radiation in Co-60 facility at ESTEC showed that the chosen model organism, Schizophyllum commune, is able to survive in 20 Gy and 200 Gy dose levels, with the ~30% of colony forming units at 200 Gy. The lower levels of gravity will also not affect the growth of the fungus. Experiments with the random positioning machine (RPM) showed that Schizophyllum commune 227 grows even faster in simulated microgravity conditions than at 1G. The proposed production process of the biocomposite on the Moon or Mars would require cultivating the mycelium of Schizophyllum commune (SC) in-situ from a minimum amount of starter culture brought from Earth. This would be combined with locally grown Azolla filiculoides (AF), an aquatic fern, with the ability to rapidly increase its biomass growing on water, while fixing nitrogen and carbon directly from atmosphere. For an additive construction experiment with a 6-axis robotic arm a mixture of SC mycelium, AF, water and psyllium was used to generate an extractable paste through a nozzle system to fabricate a number of prototypes with different print parameters.