Optical Waveguide Solar Plant Lighting System for Life Support in Space

Physical Sciences Inc. (PSI) has been developing an innovative solar plant lighting system for life support in space. In this system, solar radiation is collected by the concentrator which transfers the concentrated solar radiation to the optical waveguide (OW) transmission line consisting of low-loss optical fibers. The OW line transmits the solar radiation to the selective beam splitter where the solar spectra is divided into two components: plant lighting spectra (l < 700 nm) and power generation spectra (l > 700 nm). The plant lighting spectra are transmitted to the plant growth chamber where the solar radiation from the optical fibers is defocused for optimum intensity for plant growing. This paper discusses the results of the NASA program conducted by PSI and the Department of Agricultural and Biosystems Engineering at The University of Arizona (UA). Results of the solar correction and transmission experiments, PAR intensity data in the plant growth chamber, separation of solar spectra, and overall system efficiency of the system are discussed. In addition, results of plant growth experiment using the solar light delivered by the OW transmission line are discussed.