Integrating physicochemical and biological technologies into a regenerative life support system is a complex technical challenge. NASA recognizes that the depth and breadth of the challenge warrants a comprehensive investigation. NASA is implementing several ground-based projects to look at different systems integration issues. The combined efforts of these activities will enable NASA to develop regenerative life support systems for human exploration of the solar system in the 21st century. This paper provides an overview of NASA's overall approach to ground testing of integrated regenerative life support systems.