About this book:

"Closed-Loop Living: Regenerative Life Support for Long-Duration Missions" delves into the intricate engineering and biological challenges of sustaining human life in space for extended periods, where resupply is minimal or nonexistent. The book systematically breaks down life support into three fundamental "loops": water, air, and food, emphasizing the imperative of regenerative systems to minimize launch mass and maximize mission endurance. It argues that closed-loop living transforms consumables into circulating resources, shifting the paradigm from rationing scarcity to cultivating abundance, critical for distant destinations like Mars.

The text details the physicochemical and bioregenerative approaches within each loop. For water, it covers filtration, distillation, and catalysis for purification, along with the architecture for managing hygiene, potable, urine, and condensate streams in microgravity. The air loop explores carbon dioxide removal using sorbents, oxygen generation via electrolysis, and trace contaminant control, often integrating with Sabatier reactors to reclaim water and carbon. Food systems introduce controlled environment agriculture, including crop selection, lighting, and soilless cultivation techniques, alongside microbial and algal bioprocesses for waste stabilization, nutrient recovery, and supplementary oxygen production. Each chapter highlights the unique challenges posed by microgravity, radiation, and contamination risks, and the need for robust, reliable, and maintainable solutions.

A significant focus is placed on the overarching systems engineering framework, including requirements definition, trade studies, and multiobjective optimization, using metrics like Equivalent System Mass (ESM) to compare diverse technological options. The book also addresses crucial cross-cutting themes such as thermal control and humidity management, solid waste handling and resource recovery, microbial safety and planetary protection, and the integration of In-Situ Resource Utilization (ISRU) for harvesting local resources on planetary surfaces. Human factors, operations, crew workload, and the development of sensors, autonomy, and digital twins are explored as essential components for ensuring crew well-being and operational efficiency in environments far from Earth.

Finally, the book examines scaling strategies and phased deployment, recognizing that life support systems must evolve from compact transit architectures to larger, more biologically integrated surface habitats. It concludes by discussing programmatics, risk management, and roadmaps for future exploration, underscoring that the success of long-duration missions hinges on a holistic, adaptive approach that balances ambition with engineering rigor, ensuring that these complex, interdependent systems can reliably sustain human presence across the vast and unforgiving expanse of space.