Crew-Dependent CO₂ Fluctuations in Space Simulations for Future Bioregenerative Life Support Systems

The regulation of carbon dioxide (CO₂) concentration is a fundamental aspect of maintaining safety and habitability in isolated spacecraft environments. Elevated CO₂ levels are known to impair cognitive function, disrupt physiological homeostasis, and increase long-term health risks for crew members during extended missions but can be advantageous for photosynthetic organisms. This study introduces a computational modeling framework to predict CO₂ accumulation and removal dynamics in closed space habitats, integrating parameters such as human metabolic CO₂ production, ventilation performance, chemical scrubbing efficiency, and atmospheric leakage. Data from twelve analog missions conducted in confined habitat environments were analyzed to evaluate diverse operational and crew scenarios. Correlations between multiple environmental and physiological data were taken into consideration. The results demonstrate that variations in crew size, metabolic activity, and life support system efficiency substantially influence atmospheric stability. The findings provide quantitative guidance for defining safe operational thresholds, optimizing scrubber deployment, and establishing redundancy strategies in Environmental Control and Life Support Systems (ECLSS), thereby contributing to the development of resilient life support architectures for future long-duration human spaceflight missions.