Testing agricultural fluid handling in microgravity
As humanity explores deeper into space, long-duration missions will require horticulture activities to provide food, oxygen, and psychological benefit to astronauts. The AgriFuge is a rotating plant habitat that provides simulated gravity as well as a controllable irrigation system. Simulated gravity enables certain plant functions, such as circumnutation of growing vines. Additionally, one of the biggest challenges in the development of in-space horticulture is irrigation, as fluid handling in micro-gravity is usually a challenge. On the ZeroG flight, AgriFuge will test the rotational irrigation system.
Past experiments such as VEGGIE relied on passive wicking to irrigate their plants; however, this system was subject to failure modes of over or under-watering plants. The Advanced Plant Habitat (APH), was developed afterward with an automated irrigation system. For long-duration missions, the psychological stresses on astronauts are exacerbated. Caring for plants can be one source of stress alleviation in space. This specific AgriFuge experiment combines both a controllable irrigation system as well as incorporates human caretaking by allowing the habitat to be manually spun. Specifically, the ZeroG flight will be used to test the consistency of an astronaut who will manually spin the habitat. The astronaut will be aided with a visual indicator to give feedback to his or her activities.
The manually spun experiment (above) is complemented by a mechanically actuated sphere (below) that will determine the relationship between set rotation rates and water flow rate. The internal fluid handling systems are identical in both experiments. By characterizing the rotation rates needed for different flow rates, the controlled experiment lays the groundwork for AgriFuge to support a diverse selection of agricultural species, each with unique irrigation requirements.