system. Unit costs for several system options, as noted above, appear in Table III. Comparison with current program cost estimates can be made by noting that the development and construction cost of the space-station's 75-kWe state-of-the-art photovoltaic system is approximately $1.5 billion, not including transportation, assembly, or ground-system costs. To estimate operational and maintenance costs, it is assumed that commercial power satellite and relay spacecraft lifetimes are 15 years (the current generation of commercial communications satellites are being designed for 12-year lifetimes, and the previous generation outlived their design lifetimes by as much as 100%). Hence resupply and maintenance activity is not considered in operational cost estimates, since it is likely that in at least the early phases of central-station space power delivery service the spacecraft will become obsolete long before the end of its 15-year design life. The only other operational and maintenance costs are those associated with ground control of the orbiting systems. These are sufficiently low, compared with development and deployment costs of the central-station system, that they need not be considered at this conceptual stage of planning. REFERENCES [1] Merrifield, D.V. & Offik, W.G. (1966) Feasibility study of an orbiting energy depot, Proceedings of the Southeast Symposium on Missiles and Space Vehicle Services, Huntsville, AL, USA, November 4. [2] Hansen, C.F. & Lee, G. (1972) Laser power stations in orbit, Astronautics and Aeronautics, July, pp. 41-56. [3] Hazelrigg, G.A. & Heiss, K.P. (1976) Space-based solar power conversion and delivery system study, Final Report, June 30, (ECON, Inc.). [4] Anon (1977) Reactors for Space Electrical Power (Los Alamos Scientific Laboratory). [5] Grey, J. (1977) A rationale for large space-based solar power systems, AIAA Paper No. 77-510, St. Louis, MO, 1 March. [6] Bain, C.N. (1978) Potential of Lasers for Satellite Power System Power Transmission, R-1861, September (McLean, VA., PRC Energy Analysis Co.). [7] Jones, W.S., Morgan, L.L., Forsyth, J.B. & Skratt, J.P. (1978) Laser power conversion system analysis, Final Report, Volumes I and II, NASA CR 159523, September. [8] Woodcock, G. (1978) Solar power satellite systems definition, AIAA/RAeS Conference on Energy and Aerospace, London, UK, 5 December. [9] Brown, W.C. (1979) A profile of power transmission by microwaves, Astronautics and Aeronautics, May. [10] Herendeen, R.A., Kary, T. & Rebitzer, J. (1979) Energy analysis of the satellite power system, Science, 205, August 3, pp. 451-454. [11] Fordyce, S.W. & Brown, W.C. (1979) Applications of free-space microwave power transmission, Astronautics and Aeronautics, September. [12] Grey, J. (1979) Satellite Power System Technical Options and Economics (Office of Technology Assessment, US Congress, 14 November). [13] Walbridge, E.W. (1980) Laser Satellite Power Systems, ANL/ES-92, January (Argonne National Laboratory, USA). [14] Scott-Monck, J.A., Stella, P.M. & Berman, P.A. (1980) The applicability of
RkJQdWJsaXNoZXIy MTU5NjU0Mg==