For years, the Plant Growth Unit (PGU) was the best plant growth chamber for studying tiny plants in space. Yet, scientists and engineers found numerous ways to upgrade the PGU, enhancing many pieces of equipment while maintaining the same dimensions, and they called this upgraded version the Plant Growth Facility (PGF). This system had a much higher-output lighting system, could accommodate experiment-specific growth media, and was capable of controlling humidity, temperature, and CO2 concentration. Like the PGU, the PGF was a platform for plant reproduction experiments, and it helped demonstrate how ventilation and extra CO2 are needed for seeds to develop normally in space. In 1997 the PGF flew on the shuttle for 15 days to test the effects of microgravity on plant growth for the Collaborative Ukraine Experiment (CUE).
Chamber Components:
- One PGF holds up to six removable, airtight Plant Growth Chambers (PGCs)
- Atmospheric Control Module (ACM) controls CO2, temperature and humidity, and filters out ethylene and trace organics
- Fluorescent Light Module (FLM) (220 umol/m2s, on a timer)
- Growth area holds seedlings (seeds sandwiched between filter paper-like material)
- Command and Data Management System (CDMS) (computer, power supplies, switching assembly, battery supply, and a signal conditioning module)
- Generic External Shell (GES) for structural support
- Support Structure Assembly (SSA) to house the other sub-assemblies inside the GES
References:
- Review and analysis of plant growth chambers and greenhouse modules for space (link)
- Plant Growth Facility: A Recent Design Provides Improved Capabilities for Use in the Shuttle Middeck (link)
- STS-87 (88) Mission (link)
- A Report on The Collaborative Ukrainian Experiment-Teachers and Students Investigating Plants in Space (CUE-TSIPS). (link)
- A Researcher’s Guide to the International Space Station: Plant Science (link)