Flight Dynamics Software Industrialisation for Inclined Orbits

Abstract: The geostationary orbit has many applications for Earth observation and telecommunications. Like all satellites, spacecraft in this type of orbit are affected by perturbations. These perturbations can modify the satellites trajectories and, without control, deviate them from their target position. In order for these spacecraft to keep their target orbit, station keeping manoeuvres are required. These orbital manoeuvres are performed by thrusters − electrical or chemical − and are thus platform dependent. As part of the ground segments, Flight Dynamics Software programs are used to plan these manoeuvres, taking into account perturbations and orbital propagation – which is the prediction of the orbital evolution of the satellites – as well as the specific spacecraft configuration. Telecommands are then sent periodically to the spacecraft through the ground stations to execute the manoeuvres. Part of the manoeuvres goal is to control the inclination drift, but during the end-of-life of the spacecraft it is also possible to save some fuel − and thus increase the mission lifetime − by not controlling the inclination anymore. In this paper, inclined orbit station keeping strategy and algorithms are developed to an industrial level for a specific spacecraft platform: the SpaceBus Neo, a geostationary platform developed by Thales Alenia Space within ESA’s Neosat program. Additionally, some inclined orbits produced by the developed software are presented and analysed.