Regenerative Life Support Systems (RLSS) Test Bed Development at NASA-Johnson Space Center 911425

Future manned habitats for a Lunar outpost or Martian base will require increased levels of self-sufficiency over Space Station Freedom to reduce the high costs and complexities of resupplying expendables, such as food for the crew. By growing food at these remote sites, not only will self-sufficiency be greatly increased, but significant benefits for crew life support will also be realized. Higher plants, such as those grown typically for food, are capable of consuming carbon dioxide (CO₂), producing oxygen (O₂), and reclaiming water (H₂O) via transpiration.

At NASA's Johnson Space Center (JSC) in Houston, Texas, the Regenerative Life Support Systems (RLSS) Test Bed project will use higher plants grown in a closed, controlled environment in conjunction with physicochemically-based life support systems to create an integrated biological/physicochemical RLSS. Additionally, a human metabolic simulator will be integrated into the RLSS and will supply variable metabolic loads to the system to simulate the presence of a crew. The integrated RLSS will be fully automated to grow crops from seed to harvest without the need for human intervention. One of the test bed's two growth chambers, the Variable Pressure Growth Chamber (VPGC), will be operable both at ambient atmospheric pressures and at reduced pressures to more closely duplicate candidate Lunar or Martian habitat environments. Major objectives of the test bed include quantification of life support capabilities of higher plants, determination of interactions between the biological and physicochemical life support system components, and definition of integrated control system approaches for providing variable life support capabilities on-demand. Data from the RLSS Test Bed will be used to define requirements for a future human-rated RLSS test facility to be developed by NASA.

This paper describes the first phase of the RLSS Test Bed project development and buildup, including development of an overall systems design for the test bed, outfitting of the VPGC with plant growth systems, outfitting of a centralized control room for the test bed, and development of an initial supporting research laboratory.