System and Sustainability Determinants of Life in Space: A Determinants-Based Conceptual Framework for Human Health Beyond Earth

The expansion of human activity beyond Earth requires conceptual models to understand and support health, well-being, and sustainability in extraterrestrial environments. This article presents the System and Sustainability Determinants of Life in Space (SSDLiS) framework, an early-stage conceptual model grounded in the logic of the Social Determinants of Health and the Social Determinants of Mental Health. SSDLiS identifies nine interdependent domains proposed to influence human survival and adaptation in space: (1) Physical and Environmental Habitat, (2) Life Support and Resource Sustainability, (3) Technological Infrastructure and Operational Reliability, (4) Health and Biological Systems Maintenance, (5) Psychosocial and Behavioral Adaptation, (6) Cultural and Ethical Determinants, (7) Governance and Policy Structures, (8) Learning and Systems Adaptability, and (9) Intergenerational and Reproductive Health. The framework is conceptual rather than empirical and is intended to guide interdisciplinary inquiry linking engineering, life sciences, behavioral health, and ethics. Within the broader New Space landscape, SSDLiS provides a systems-based perspective for integrating human sustainability into the design, governance, and commercialization of space habitats and missions. By reframing determinants of health and well-being for the conditions of space, the model advances a holistic, human-centered approach to sustainability that supports adaptation and thriving beyond Earth.