construct such a satellite and the cost of space transportation could thus be greatly reduced. The second approach would involve a similar system for gathering solar energy and beaming it to receptors on Earth, but would be built on the lunar surface. This lunar-based system, built from the raw materials at hand would also significantly reduce the number of launches required from Earth. In order to ensure a continuous supply of terrestrial power it would be necessary to install a power station on each side of the moon lit up in turn by the sun. A system of mirrors in terrestrial orbit would enable the microwave beam to reach the hidden sides of the Earth; another system in lunar orbit could reflect additional solar power over to the solar panels, especially during the rising and setting of the sun as well as during eclipses. Proposed by David Criswell, this project anticipates the possible delivery to Earth of 20,000 GW useful power. A third approach may offer the greatest breakthrough potential, but will depend on both space-based and terrestrial technology development programs. Studies of the Moon have shown that an isotope rare to the Earth, helium 3, exists in great quantities (but low concentrations) on the lunar surface. More recent studies have shown that helium 3 has great promise as a fuel for nuclear fusion reactions. This fusion in particular produces very few neutrons, which reduces damage to the reactor’s walls. The level of contamination would also be limited even further. However, the D-He3 fusion procedure still needs in-depth research before being able to formulate a true diagnosis of its real perspectives. SPS and the Environment In general, the SPS appears to be a relatively benign technology avoiding many of the risks associated with options such as coal or nuclear power. Once the construction phase is over, the SPS need release no effluents of any kind to the biosphere; and only hydro power is as efficient, in terms of terrestrial waste heat generation. A variety of potential environmental concerns have however been identified. Many of the effects are not well understood and some may have longterm consequences. An intensive research effort is needed so that data can be available at appropriate decision points in the SPS development program : The potential impact of SPS must be evaluated in a manner and with resources that will instil confidence. microwave biological effects, space construction and operation, rectenna construction and operation, microwave effects in the ionosphere, - space transportation effects, electromagnetic compatibility, effects on astronomy, resource utilization and industrial effects.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==