Research was conducted to identify and develop technologies for rapid plant growth in a variety of gravitational environments. Low-gravity environments pose problems like effectively delivering water and nutrients to plants and recovering the effluents. Food production in space faces other challenges including water handling, minimization of water use, and minimization of the systems weight. Food production on planetary bodies like the Moon and Mars will also require dealing with reduced gravity environments. Because of the different fluid dynamics present at differing levels of gravity a major focus in developing plant growth systems has been optimizing nutrient delivery systems.