A ground-based facility for the study of plant growth and development under stringently controlled environments is being developed by the CELSS program at the Ames Research Center. Several Crop Growth Research Chambers (CGRC) and laboratory support equipment provide the core of this facility. The CGRC is a closed (sealed) system with separate recirculating atmosphere and nutrient delivery systems. Environmental influences on gas exchange, growth and development, and biomass and food production of crop plants growing within the closed environment will be investigated. Laboratory size of the CGRC will be small enough to allow treatment replication but large enough to provide information representative of larger plant communities. Water recovery and management systems and gas management systems will be included. Eventual integration of candidate waste processing technologies into the cycling system is intended.Development of a Controlled Ecological Life Support System (CELSS) requires identification of the critical requirements that will allow the system to operate with stability and efficiency. Identifying and meeting those requirements will be accomplished through scientific experimentation and technology development on the ground. A Crop Growth Research Facility has been defined by CELSS principal investigators and science advisory panels as necessary for the development of a bioregenerative life support system (1,2).The crop growth research facility is for the study of plant growth and development under stringently controlled environments isolated from the external environment. This facility is important for three CELSS activities: 1) research, 2) system control and integration, and 3) flight hardware design and experimentation. Several Crop Growth Research Chambers and laboratory support equipment provide the core of this facility. The Crop Growth Research Chamber (CGRC) is a closed (sealed) controlled environment system designed for the growth of a community of crop plants with separate recirculating atmosphere and nutrient delivery systems.