title: Achieving and documenting closure in plant growth facilities.
abstract: As NASA proceeds with its effort to develop a Controlled Ecological Life Support System (CELSS) that will provide life support to crews during long duration space missions, it must address the question of facility and system closure.  Here we discuss the concept of closure as it pertains to CELSS and describe engineering specifications, construction  problems and monitoring procedures used in the development and operation of a closed plant growth facility for the CELSS program.  A plant growth facility is one of several modules required for a CELSS.  A prototype of this module at Kennedy Space Center is the large (7m tall x 3.5m diameter) Biomass Production Chamber (BPC), the central facility of the CELSS Breadboard Project.  The BPC is atmospherically sealed to a leak rate of approximately 5% of its total volume per 24 hours.  This paper will discuss the requirements for atmospheric closure in this facility, present CO2 and trace gas data from initial tests of the BPC with and without plants, and describe how the chamber was sealed atmospherically.  Implications that research conducted in this type of facility will have for the CELSS program are discussed.
authors.affiliation: Biomedical Operations and Research Office, J.F. Kennedy Space Center, FL 32899.
authors.forename: W M
authors.initials: WM
authors.lastname: Knott
authors.forename: J C
authors.initials: JC
authors.lastname: Sager
authors.forename: R
authors.initials: R
authors.lastname: Wheeler
mesh_terms: D001272:Atmosphere; D002245:Carbon Dioxide / Q000378:metabolism; D018504:Ecological Systems, Closed; D004784:Environmental Monitoring; D004867:Equipment Design; D008021:Life Support Systems / Q000295:instrumentation*; D010101:Oxygen Consumption; D010788:Photosynthesis; D063245:Plant Development; D010944:Plants / Q000378:metabolism; D013026:Space Flight / Q000295:instrumentation*; D014908:Triticum / Q000254:growth & development / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide