Space Biomanufacturing of Lactic Acid: Conceptual Design and Techno-Economic Analysis

Space biomanufacturing is an emerging paradigm to support long-term missions by generating products on-site and thereby reducing the high cost of resupply. This is done by creating circular manufacturing systems based on biological processes that are capable of recycling waste to minimize the need for make-up resources. This paradigm is motivated by the fact that deployment cost of a space system depends strongly on the cost of transportation of system components and resources, which is directly proportional to their mass. The total system mass is thus a critical factor that dictates its design; specifically, mass constraints require tight system integration and restricts the type of resources and equipment used (e.g., for production, heating/cooling, and storage). In this work, we present a computational framework to conduct design and techno-economic analysis of space biomanufacturing systems for lactic acid. Lactic acid (LA) is a platform chemical that can be converted into polylactic acid (PLA) for habitat construction. The framework is used to inform the selection of the best organisms and their preservation methods. We use the Equivalent System Mass (ESM) metric as the key design metric that maps system components (e.g., energy, resources, equipment) to a common mass basis. Our analysis reveals that the preservation modality plays a key role in overall system mass due to primarily to energy use. We also found that lyophilized cultures can reduce storage energy use by up to 99%. By leveraging in situ resource utilization, a 8 ton system could produce the sufficient PLA for fabricating a lunar habitat, with nearly a 90% reduction in logistical cost. In addition, we find that radiation-induced reductions in microbial yield can increase system mass by up to 28%. These findings highlight how a system mass centered approach can guide the design of modular, resource-efficient biomanufacturing systems for future space habitats.