In-situ resource utilization (ISRU) is increasingly acknowledged as an essential requirement for the construction of sustainable extra-terrestrial colonies. Even with decreasing launch costs, the ultimate goal of establishing colonies must be the usage of resources found at the destination of interest. Typical approaches towards ISRU are often constrained by the mass and energy requirements of transporting processing machineries, such as rovers and massive reactors, and the vast amount of consumables needed. Application of self-reproducing bacteria for the extraction of resources is a promising approach to reduce these pitfalls. In this work, the bacterium Shewanella oneidensis was used to reduce three different types of Lunar and Martian regolith simulants, allowing for the magnetic extraction of iron-rich materials. The combination of bacterial treatment and magnetic extraction resulted in a 5.8-times higher quantity of iron and 43.6% higher iron concentration compared to solely magnetic extraction. The materials were 3D printed into cylinders and the mechanical properties were tested, resulting in a 400% improvement in compressive strength in the bacterially treated samples. This work demonstrates a proof of concept for the on-demand production of construction and replacement parts in space exploration.

Transporting materials from Earth to Mars is a significant logistical constraint on mission design. Thus, a sustained settlement will be enhanced if it can perform elemental extraction and utilization in situ. In this study, all requirements to test a novel, biological approach for in situ resource utilization (ISRU) are conceptualized. We present designs for two bioreactor systems to be incorporated in a Mars habitat. The first system is a standard algae bioreactor which produces oxygen and biomass. The second bioreactor is capable of taking in Martian regolith and extracting enhanced iron ores from it via biological processes. Additionally, we propose the use of the leftover iron-poor but biomass rich material in a plant compartment. The multiple, different compartments feed into each other, creating an interconnected process enhancing self-sufficiency. In this paper, computational fluid dynamics of mixing behavior under reduced gravity, a breakdown of the process flow for a biological ISRU approach and exploratory in silico evaluation of the feasibility are presented.