SPS Feasability Study SD76SA0239-2

Minimum thruster counts for all functions are increased by a factor of 1.5 to permit maintenance of failed components without compromising mission performance. Power conditioning units are required for each thruster. Power conditioning unit mass is estimated at 5.24 kg/kw. The propellant storage and feed system is sized to store a one-year supply of argon as a high pressure gas. Table 2.4-1 summarizes annual estimated propellant requirements. High pressure tanks of titanium operating at a maximum pressure of 2415 newtons/cm^ (3500 psi) were selected. From Figure 2.4-3^ total tank mass is estimated at 170,000 kg. The remainder of the feed system (valves, lines, flanges, mounting brackets, etc.) is estimated at 34,000 kg. Total mass of the control system is summarized in Table 2.4-2. Table 2.4-1. Satellite Propellant Requirements