Search Results

The Plant Generic BioProcessing Apparatus (PGBA), a plant growth facility developed for commercial space biotechnology research, has flown successfully on 3 spaceflight missions for 4, 10 and 16 days. The environmental control systems of this plant growth chamber (28 liter/0.075 m2) provide atmospheric, thermal, and humidity control, as well as lighting and nutrient supply. Typical performance profiles of water transpiration and dehumidification, carbon dioxide absorption (photosynthesis) and respiration rates in the PGBA unit (on orbit and ground) are presented. Data were collected on single and mixed crops. Design options and considerations for the different sub-systems are compared with those of similar hardware.

Through the development of 35 spaceflight payloads during the last ten years, BioServe Space Technologies has gained valuable practical experience in developing thermal control systems for the microgravity environment. Design constraints imposed by NASA, such as limited power availability, limited material selections, and limited acoustic emissions, coupled with the design constraints imposed by the functional requirements of each payload, impact spaceflight designs in a manner that requires a high degree of optimization. BioServe payloads typically employ thermoelectric coolers (TEC's), air and liquid heat exchangers, a variety of insulation materials, several types of fans and blowers, and various control strategies in order to achieve the desired thermal environment. In the present work methods of selecting thermal system components are discussed.

PGBA, a plant growth facility developed for commercial space biotechnology research, successfully grew a total of 50 plants (6 species) during 10 days aboard the Space Shuttle Endeavor (STS-77), and has reflown aboard the Space Shuttle Columbia (STS-83 for 4 days and STS-94 for 16 days) with 55 plants and 10 species. The PGBA life support system provides atmospheric, thermal, and humidity control as well as lighting and nutrient supply in a 33 liter microgravity plant growth chamber. The atmosphere treatment system removes ethylene and other hydrocarbons, actively controls CO2 replenishment, and provides passive O2 control. Temperature and humidity are actively controlled.