This system uses natural occurring zeolite minerals as a basic material to provide a favorable root medium in which to grow the plants. In this program it was recognized that there was a need to incorporate the growth of plants into the system to produce food and convert the carbon dioxide to oxygen by means of plant photosynthesis. The Zeoponic plant growth system was initiated for laboratory and space flight testing. Two patent applications have been filed by NASA that describe the materials and methods used.
Plants are an important component of regenerative life support systems for long-duration missions.
In addition to supplying food, plants have the capability to regenerate air by converting CO2 back into O2 and, through evapotranspiration, plants can convert wastewater into potable water. For these reduced gravity applications, it is desirable to develop a substrate that provides the plant essential elements in a static watering system which eliminates circulating pumps and monitoring systems. These synthetic soils have been termed zeoponic plant growth substrates. Zeoponics is defined as the cultivation of plants in zeolite mineral substrates that contain essential, plant-growth nutrients. Zeolites have the capability to freely exchange some of their constituent ions with ions in solution without change to their structural framework.