is also feasible. Both conditions will spread specular reflections and reduce the local intensity of ground irradiance by distributing the light over a larger area. For example a 5° misalignment results in a 100-fold reduction in ground irradiance. Surface Quality. The Baseline Space Power System Design includes many surfaces that have specular characteristics in visible light. This surface quality can be altered for some of the applications without affecting the serviceability of the element. For example, the surface of the SPS antenna is an electrical ground plate that presently is polished aluminum; but its electrical properties at the microwave frequencies of interest would not be affected by surface roughening (etching) on the scale size of visible wavelengths to create'a diffuse reflector. Clearly there are options available to reduce ground irradiance from sunlight reflections off the Space Power System spacecraft. How effective they would be and how practical they are for overall performance and cost remains to be assessed. 1. Satellite Power System, Concept Development and Evaluation Program, Reference System Report, U.S. Department of Energy, Office of Energy Research and National Aeronautics and Space Administration, October 1978. Solar Power Satellite, System Definition Study, Phase I Final Report, Contract NAS 9-15636, Boeing Aerospace Company Document DI80-25037-3, April 1, 1979. 2. Livingston, L. E., "Visibility of Solar Power Satellites From the Earth", Johnson Space Center, NASA JSC-14715, February 1979. 3. Tingey, D. L. and H. B. Liemohn, "Characterization of Reflected Light from the Space Power System", Boeing Contract Report DI80-25923-1 to Argonne National Laboratories, March 1980. 4. Liemohn, H. B., "Optical Tracking of Deep-Space Probes", ICARUS: International Journal of the Solar System, Vol. 9, No. 1, July 1968.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==