SPS Feasability Study SD76SA0239-2

array and reflector will be reduced by approximately 1.7 percent, as shown in the figure. A combined reflectivity and on-orbit degradation of 90 percent was used in the analysis. A good grade aluminum coating with a quartz or calcium fluoride film will attain a performance goal of 90 percent for long operational durations. The SPS inboard reflectors operate at a nominal steady-state temperature of -48°C and the outboard reflectors at a steady state temperature of -53°C. A thermal analysis was performed on the SPS to determine the SPS solar array and structure steady-state temperature. The thermal levels and temperature differences substantially influence power levels, size, operating efficiency, and structural integrity. The SPS structural configuration that was analyzed in the study is shown in Figure 2.2-16. Figure 2.2-15. Vee Channel Solar Array Concentration Ratio as Function of Misorientation Angle