Optical Waveguide Solar Power System for Material Processing in Space

The conventional concept for solar energy utilization in space is converting solar radiation to electricity and then using the electric power for various applications. For some applications, however, it is more efficient to utilize solar energy directly. Oxygen production from lunar regolith, for example, can be accomplished by using solar thermal power directly for thermochemical reduction of lunar oxides. Space-based plant growth can use photosynthetically active radiation (PAR) from solar spectra for biomass production and life support. The authors and their colleagues have been developing a new solar power system called the optical waveguide (OW) system for solar power utilization in space. In this system, solar radiation is collected by the concentrator array, which transfers the concentrated solar radiation to the OW transmission line made of low loss optical fibers. The OW transmission line directs the solar radiation to the site of solar power utilization. This paper discusses the technical background of the OW system and reviews development and testing of the engineering prototype of the OW solar thermal system during the National Aeronautics and Space Administration (NASA) in situ resource utilization (ISRU) analog test in 2010. Based on the results, performance and viability of the OW system in application to space solar power utilization are discussed.