The Crew and Thermal Systems Division at NASA Johnson Space Center under the sponsorship of NASA Headquarters Office of Life and Microgravity Sciences and Applications is conducting the Early Human Testing (EHT) project. The goal of the multi-year EHT project is to provide NASA with a ground-based test bed facility used to demonstrate the feasibility of regenerative life support technologies involving both physicochemical and biological processes to sustain human life for extended periods in a closed environment. The EHT project is organized into three distinct phases to provide progressively more complex integration of biological and physicochemical life support systems. While Phase I focuses on biological life support, Phase II is an intermediate testing program scheduled to support 4 persons for 15 days in a closed environment utilizing physicochemical life support systems. Phase III of the EHT project will integrate both biological and physicochemical systems to support a 4 person, 90-day test and ultimately demonstrate the maturity of these technologies to enable future human space and planetary exploration. This paper describes the ground-based test bed facility development including test article integration, testing philosophy and management of EHT Phases II and III.