Attitude Dynamics of Large Geosynchronous Solar Power Satellites

The solar power satellite (SPS) is an extremely large satellite designed to collect solar energy in space and transmit it to Earth via microwaves. A direct comparison between the attitude dynamics of SPS in the geosynchronous Laplace plane (GLP) orbit and in geostationary Earth orbit (GEO) is made. Initially, the Abacus SPS oriented perpendicular to the orbit plane (POP) is considered. It is found that by locating the Abacus SPS in GLP, attitude control is more costly. However, when both attitude and orbit control are considered, fuel savings of 17, 000 kg/year are achievable compared to in GEO. The benefits of modifying both the mass distribution and the attitude orientation of the Abacus SPS are analyzed. For Abacus type SPSs oriented in the orbital plane (IOP) which employ two dimensional inertia balancing (2-DIB), GLP offers more significant fuel savings of ∼ 73, 000kg/year. Orbit and attitude control for a SPS-IOP with 2-DIB in GLP requires 2.3% of the overall mass in fuel over a 30 year lifetime compared to 10.1% for the original Abacus SPS-POP in GEO. However, a system of solar reflectors is required for the IOP orientation, adding complexity to the design.