Climatological and heating effects of the microwave power transmission system in the lower atmosphere.
Between 60 and 500 km, the atmosphere is subject to modification from rocket thruster effluents and from oblation materials generated upon vehicle reentry. The major effects appear to occur in the ionospheric F2 region, resulting primarily in enhanced airglow. While not posing any threat to safety at ground level, it may affect planetside optical sensing devices. Beyond 500 km, the effects are related to heavy ion concentration due to rocket effluents, and to electric and magnetic fields generated by the orbiting SPS. These potential problems are not well understood and require further study. Because of deficiencies in our understanding of the physical and chemical processes above 40 or 50 km, especially with regard to water budget, there is a large uncertainty connected with any prediction. However, climatic effects that may arise from SPS-related perturbations in stratospheric and mesospheric composition are not expected to be highly significant (U.S. DOE, 1978a).
President Carter approved the SPS Project and gave it a go-ahead, in spite of the reservation which many reviewers, myself included, expressed. Fortunately, it was so expensive, exceeding the entire Department of Energy budget, that funding was denied by the Congress. I approached the United Nations Committee on Disarmament on this project, but was told that as long as the program was called Solar Energy by the United States, it could not be considered a weapons project. The same project resurfaced in the US under President Reagan, moved to the much larger budget of the Department of Defence, and called Star Wars. 
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