title: Johnson Space Center's Regenerative Life Support Systems Test Bed.
abstract: The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems.  The facility supports NASA's Advanced Life Support (ALS) Program.  The facility is comprised of two large scale plant growth chambers, each with approximately 11 m2 growing area.  The root zone in each chamber is configurable for hydroponic or solid media plant culture systems.  One of the two chambers, the Variable Pressure Growth Chamber (VPGC), is capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in a planetary surface habitat; the other chamber, the Ambient Pressure Growth Chamber (APGC) operates at ambient atmospheric pressure.  The air lock of the VPGC is currently being outfitted for short duration (1 to 15 day) human habitation at ambient pressures.  Testing with and without human subjects will focus on 1) integration of biological and physicochemical air and water revitalization systems; 2) effect of atmospheric pressure on system performance; 3) planetary resource utilization for ALS systems, in which solid substrates (simulated planetary soils or manufactured soils) are used in selected crop growth studies; 4) environmental microbiology and toxicology; 5) monitoring and control strategies; and 6) plant growth systems design.  Included are descriptions of the overall design of the test facility, including discussions of the atmospheric conditioning, thermal control, lighting, and nutrient delivery systems.
authors.affiliation: Lyndon B. Johnson Space Center, NASA, Houston, TX 77058, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Barta
authors.forename: D L
authors.initials: DL
authors.lastname: Henninger
mesh_terms: D001274:Atmospheric Pressure; D003199:Computer Systems; D018504:Ecological Systems, Closed; D004780:Environment, Controlled; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005160:Facility Design and Construction; D006801:Humans; D018527:Hydroponics / Q000295:instrumentation; D008021:Life Support Systems / Q000295:instrumentation*; D008027:Light; D063245:Plant Development; D018561:Space Simulation; D018511:Systems Integration; D014481:United States; D018557:United States National Aeronautics and Space Administration