Extending GEO Satellite Operations: Timing and Challenges of Inclined Orbit Transitions

Abstract

Maximizing the operational lifespan of Geostationary Earth Orbit (GEO) satellites is a critical objective for satellite operators. Throughout their service life, satellites are maintained within a designated control box through North–South (NS) and East–West (EW) station-keeping maneuvers. NS maneuvers, which adjust the satellite's inclination relative to the equatorial plane, require significantly more propellant than EW maneuvers. As a result, operators often choose to discontinue NS maneuvers, allowing the satellite to transition into an “inclined orbit” while relying on EW maneuvers to manage orbit drift and maintain longitude positioning. This approach is typically adopted when the satellite nears the end of its operational life or when fuel conservation becomes a priority. A critical challenge in this process is determining the optimal timing for initiating inclined orbit, which involves carefully balancing factors such as fuel availability, satellite health, mission requirements, and operational constraints. This study provides a comprehensive analysis of these factors, with a detailed exploration of timing optimization, and concludes with a practical case study to illustrate the findings.