Multi-disciplinary system design optimization for all-electric geostationary communication satellite

Geostationary communication satellites are a large market for the space utilization domain. From the user's perspective, the commercial communication payload mass is among the most important specification parameters. In order to maximize payload mass and customer satisfaction, the satellite bus mass should be minimized because the launch mass is constrained by launcher vehicle capability. Therefore, electric propulsion offers a practical design option for geostationary communication satellites, with significantly higher specific impulse than that of chemical propulsion. In fact, some satellite development organizations have already applied it to their satellites, and the Japan Aerospace Exploration Agency (JAXA) is also developing a new all-electric geostationary communication satellite equipped with Hall-effect thrusters. One disadvantage of electric propulsion is that its thrust force is much smaller than that of chemical propulsion. Although the thrust force of a Hall-effect thruster can be relatively high compared to other electric thrusters, it is generally one-tenth to one-hundredth of the thrust force of chemical propulsion. Consequently, the transition time from injected orbit to geostationary orbit is much longer, which can be recognized as greater operational risk and higher cost. The thrust force of a Hall-effect thruster can be somewhat improved by increasing its discharge power and voltage. However, this design decision not only increases the satellite bus mass but also deteriorates the specific impulse, resulting in drastically decreased payload mass. Therefore, the balance between payload mass and transition time entails critical decision-making to achieve a satellite's competitiveness in the market. This study examines the trade-off between payload mass and transition time in the all-electric geostationary communication satellite based on Hall-effect thrusters from a multidisciplinary perspective, including the thruster design, injection orbit, satellite mass, and power supply design. Overall satellite system design, including the satellite's injection orbit, is separately optimized under certain constraints as maximizing the payload mass or minimizing the transition time. Pareto frontiers are also investigated as gradually changing the weighted factors of both objectives. Finally, the non-dominant and competitive system design is discussed in comparison with the existing same type of all-electric satellite.