Plant Growth Facility: A Recent Design Provides Improved Capabilities for Use in the Shuttle Middeck

The Plant Growth Facility (PGF) is under development as a Shuttle middeck apparatus to support research on higher plants in microgravity. It is designed to operate for 15 days, and will provide (1) fluorescent lighting at a minimum of 220 μmol m^-2 s^-1 evenly distributed (±10%) over the growth area, (2) temperature control to a set point of ±10°C of cabin ambient with a control accuracy of ±1°C, (3) humidity control ±5% for set points between 30-80% RH, and (4) carbon dioxide control ±5% over a range of 300-5000 ppm. Filters will be provided to remove ethylene and trace organics from the internal air flow.