Large Plant Growth Chambers: Flying Soon on a Space Station Near You!

The International Space Station (ISS) now has platforms for conducting research on horticultural plant species, and those capabilities continue to grow.  The ‘Veggie’ vegetable production system will be deployed to the ISS in Spring of 2014 to act as an applied research platform with goals of studying food production in space, providing the crew with a source of fresh food, allowing behavioral health and plant microbiology experimentation, and being a source of recreation and enjoyment for the crew.  Veggie was conceived, designed, and constructed by Orbital Technologies Corporation (ORBITEC, Madison, WI).  Veggie is the largest plant growth chamber that NASA has flown to date, and is capable of growing a wide array of horticultural crops.  It was designed for low energy usage, low launch mass and stowage volume, and minimal crew time requirements.  The Veggie flight hardware consists of a light cap containing red (630 nm), blue, (455 nm) and green (530 nm) LEDs.  Interfacing with the light cap is an extendable bellows/baseplate secured to the light cap via magnetic closures and stabilized with extensible flexible arms.  The baseplate contains vents allowing air from the ISS cabin to be pulled through the plant growth area by a fan in the light cap.  The baseplate holds a Veggie root mat reservoir that will supply water to plant pillows attached via elastic cords.  Plant pillows are packages of growth media and seeds that will be sent to ISS dry and installed and hydrated on orbit.  Pillows can be constructed in various sizes for different plant types.  Watering will be via passive wicking from the root mat to the pillows.  Science procedures will include photography or videography, plant thinning, pollination, harvesting, microbial sampling, water sampling, etc.  Veggie is one of the ISS flight options currently available for research investigations on plants.  The Plant Habitat (PH) is being designed and constructed through a NASA-ORBITEC collaboration, and is scheduled to fly on ISS around 2016.  This large plant chamber will control light quality, level, and timing, temperature, CO₂, relative humidity, and irrigation, while scrubbing ethylene.  Additional monitoring capabilities include leaf temperature sensing and root zone moisture and oxygen sensing.  The PH light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs.  There will be several internal cameras to monitor and record plant growth and operations.