Scientific Verification Test of Orbitec Deployable Vegetable Production System for Salad Crop Growth on ISS- Gas Exchange System design and function

The ability to produce and maintain salad crops during long term missions would be a great benefit to NASA; the renewable food supply would save cargo space, weight and money. The ambient conditions of previous ground controlled crop plant experiments do not reflect the microgravity and high CO2 concentrations present during orbit. It has been established that microgravity does not considerably alter plant growth. (Monje, Stutte, Chapman, 2005). To support plants in a space-craft environment efficient and effective lighting and containment units are necessary. Three lighting systems were previously evaluated for radish growth in ambient air; fluorescent lamps in an Orbitec Biomass Production System Educational (BPSE), a combination of red, blue, and green LED's in a Deployable Vegetable Production System (Veggie), and a combination of red and blue LED's in a Veggie. When mass measurements compared the entire possible growing area vs. power consumed by the respective units, the Veggies clearly exceeded the BPSE indicating that the LED units were a more resource efficient means of growing radishes under ambient conditions in comparison with fluorescent lighting. To evaluate the most productive light treatment system for a long term space mission a more closely simulated ISS environment is necessary. To induce a CO2 dense atmosphere inside the Veggie's and BPSE a gas exchange system has been developed to maintain a range of 1000-1200 ppm CO2 during a 21-day light treatment experiment. This report details the design and function of the gas exchange system. The rehabilitation, trouble shooting, maintenance and testing of the gas exchange system have been my major assignments. I have also contributed to the planting, daily measurements and harvesting of the radish crops 21-day light treatment verification test.