Effects of Space Biomanufacturing on Fuel Production Alternatives for Mars Exploration
Sen Gupta, Soumyajit
Space biomanufacturing garners substantial attention for its potential to save launch mass and power, but biological processes are inherently slower than analogous abiotic manufacturing routes. Their delays motivate studying the trade-offs between space biomanufacturing and traditional in situ resource utilization (ISRU) technologies to meet mission needs. An important need that deserves further scrutiny is fuel production for spacecraft propulsion, because recent comparative studies between space biomanufacturing and abiotic ISRU concentrate on a single fuel, methane, and evaluate only the launch mass cost. However, there exists a rich palette of fuels attainable by both biological and chemical techniques, namely, hydrogen, C2 and C3 alkanes and alkenes, biodiesel, nitrous oxide, and hydrazine, as well as different combustion scenarios (e.g., monopropellant, or bipropellant with oxygen). Accordingly, this paper performs a comprehensive analysis of the production of fuel alternatives to capture a trade-off between propulsion efficiency, quantified by the specific impulse, and required production resources and infrastructure. The study assesses biological techniques that generate different fuels against abiotic technologies for Martian ascent. The Equivalent System Mass (ESM) metric, which augments traditional shipped mass costs with pressurized volume, demanded power and thermal control, and needed crew time, forms the comparative basis for evaluating the fuel production alternatives. A key finding is that methane bioproduction is competitive with abiotic manufacturing techniques, even under more detailed scrutiny than past analyses of methane biomanufacturing. The study also incorporates a parametric sensitivity analysis to highlight the high impact of bioproduction yield changes on non-carbon-based fuels. This work adds insight into future mission optimization through appropriate fuel production technology selection.