On the end-of-life disposal of spacecraft and orbital stages operating in inclined geosynchronous orbits

The current internationally accepted guideline for the appropriate end-of-life disposal of spacecraft and orbital stages, in order to guarantee no further long-term interference with the geosynchronous protected region, was developed when the nearly sole function of the geosynchronous region was to host geostationary satellites, maintained close to the Earth equator as much as possible. Significantly inclined geosynchronous orbits are nevertheless becoming increasingly attractive for various applications, so the original re-orbiting guideline was re-assessed to evaluate its application limits. It was found that an extension of the original formula would be possible to cover disposal inclinations up to ? 30°, with an additional velocity variation penalty <= 11.5 m/s. However, this approach will not be generally applicable for higher initial inclinations, were the disposal strategy should be addressed on a case by case basis, being strongly dependent on the initial orbital and celestial conditions.