(483g) An End-to-End Design and System Integration for Biomanufacturing on Mars Under Uncertainty

A promising route towards supporting a crew on Mars leverages biotechnological advancements with inherent mass, power, and volume advantages over alternative approaches. Within this scope, the Center for Utilization of Biological Engineering in Space (CUBES) attempts to study the efficient utilization of Martian in situ resources (ISRU) for integrated biomanufacturing of the necessary products for Martian exploration, including biologically produced pharmaceuticals, cell-based treatments/therapeutics, and materials for on-demand and modular additive manufacturing applications [1] to sustain a crewed mission over an extended period. Although a wide array of fundamental scientific breakthroughs has recently been made to develop biotic life-support technologies for deep space missions, attempts to synthesize an end-to-end biomanufacturing system with proper unit integration have been scarce. The purpose of this work is to provide a comprehensive in silico study towards ISRU to manufacture the necessary products for sustaining a human mission, while respecting unique constraints based on space biomanufacturing principles. To this end, we leverage relevant systems modeling work [2,3] to present an optimal design approach that connects the most essential elements towards a biomanufactory on Mars.

We assign the key processes involved in ISRU into useful commodities and formulate an optimization problem based on major technoeconomic considerations by using novel design metrics tied to human space exploration. We consider the case of an end-to-end biomanufacturing system that targets the downstream production of biopolymer following a sequence of upstream operations that utilize in situ resources such as water, atmosphere and sunlight. The primary source of reducing equivalents for biological CO₂ conversion to acetate is H₂, which can be obtained from solar-driven electrolysis of water. Acetate is fed to a downstream process where it acts as a primary substrate for bacteria to synthesize poly(3-hydroxybutyrate) (PHB), a biopolyester useful for additive manufacturing. To achieve an optimal design of the above integrated system, the target PHB production rates, as well as other relevant production goals, such as biomass productivity for downstream utilization, are accounted for as hard constraints, driven by the needs on food and material towards scientific exploration and survival of crew members. The mission design objective function is derived based on the extended Equivalent System Mass (xESM) metrics [4], a framework that is used to quantify the cost of some set of extraterrestrial operations, considering mass, volume, power, and crew time demands. The above constitutes a constrained, mixed-integer non-linear problem (MINLP), whose solution yields the optimal decisions for designing an integrated system to be employed, including optimal flow rates, operational times, resource allocation and system specifications. Moreover, since the simulated environment is unknown, we consider parametric uncertainty in our optimization model and extend the solution to a robust setting. Our findings pave the way towards a system engineering and optimization formulation for deep space exploration and provide estimates for biomanufacturing production costs on Mars.

[1] Berliner, A. J., Hilzinger, J. M., Abel, A. J., McNulty, M. J., Makrygiorgos, G., Averesch, N. et al., (2021). Towards a biomanufactory on Mars. Frontiers in Astronomy and Space Sciences, 8, 120.

[2] Cestellos-Blanco, S., Friedline, S., Sander, K. B., Abel, A. J., Kim, J. M., Clark, D. S., Arkin, A.P., & Yang, P. (2021). Production of PHB from CO2-derived acetate with minimal processing assessed for space biomanufacturing. Frontiers in Microbiology, 12.

[3] Abel, A. J., Adams, J. D., & Clark, D. S. (2021). A comparative life cycle analysis of electromicrobial production systems. bioRxiv.

[4] Berliner, A., Makrygiorgos, G., & Hill, A. (2021). Extension of Equivalent System Mass for Human Exploration missions on mars, Preprints