Bio-Regenerative Life Support Systems in Space Exploration: Principles, Technologies and the Role of Microorganisms in Sustainable Nutrient Recycling for Long-Term Space Mission

A Literature Review

Abstract

As humanity pursues long-duration spaceflight, sustainable life support systems are essential to sustain crew survival. In recent times, Bio-regenerative Life Support Systems (BLSS) have emerged due to its potential of integrating biological, physicochemical, and engineering technologies to ensure the recycle of air, water, nutrients, and waste within closed-loop environments and also supporting the production of sustainable food. This study synthesizes evidence on the BLSS for long-term space exploration. This review provides a comprehensive synthesis of recent evidence regarding the principles, technologies, and current innovations in BLSS, with a focus on microbial-driven nutrient recycling. A structured search was conducted on Web of Science, PubMed, and Google Scholar using key search terms. Literature relevant to the review were synthesized qualitatively and data on principles, photobioreactor technologies, artificial intelligence technology for environmental monitoring, synthetic biology, microbial protein production, and waste management and recycle strategies. Key advances in utilizing bacteria, microalgae, fungi, and cyanobacteria facilitate efficient nutrient recycling, respiratory oxygen carbon dioxide interaction, water purification, and resource recovery. Operational challenges include ecological instability, microbial contamination, microgravity interruption, nutritional quality of microbial biomass and long-term reliability of the system. The integration of microbial food systems into BLSS promotes resource efficiency, environmental resilience, and sustainability. These systems also reduce the dependence on earth resupply. However, further research is required to optimize cultivation systems, enhance long-term operational reliability, and validate these technologies in actual space environments. Although this review highlights the potential of BLSS to support human space exploration, several critical knowledge gaps remain. Thus, this review provides insights on advancement in BLSS technologies and identifies future directions to improve BLSS sustainable human habitation in space environment.