SPS Feasability Study SD76SA0239-2

slip ring conductors, the weights are much lower than in the solar arrays because of the shorter conductor lengths. After the power is delivered to the MW antenna, it must be distributed to the RF elements. The results of the NASA Lewis Raytheon Study indicated that a lateral flow power distribution system was a minimum weight system. The lateral flow system was used in this study and is shown in Figure 2.2-28. The power loss in the antenna is 2 percent and results in a voltage drop of 204v in the supply conductor and 204v in the return conductor, as shown in Figure 2.2-24. The length and current in each of the primary conductors of the MW antenna are shown in Figure 2.2-28. Based on the lateral flow distribution system of Figure 2.2-28 and a conductor operating temperature of 204°C, the total weight of the antenna conductors is 0.205 x 10$ kg. An overall summary of the power distribution weights and nominal operating voltages is presented in Table 2.2-7. The total weight of the SPS conductors for a 5-Gw ground-rated system is seen to be 4.275 x 10^ kg (9.4 x 10$ lb), or approximately 18-percent of the total SPS weight. Because of the large percentage of weight in the conductors, there are several concepts that may lend themselves to improved weight reductions and should be considered for further study. Table 2.2-8 is a summary of the design concepts for potential conductor weight reductions. Figure 2.2-28. Power Distribution Lateral Power Flow