How an aware usage of the long-term dynamics can improve the long-term situation in the LEO region

Abstract

The ReDSHIFT H2020 European project has shown, among other findings, that passive disposal procedures can benefit from the exploitation of dynamical perturbations. One key aspect of the project was a study on the dynamical disposal of spacecraft at the end-of-life by exploiting natural perturbations and identifying stable and unstable regions in the phase space, where the objects could be moved to exploit either long term “graveyards” or, possibly and preferentially, faster escape routes (the so-called “de-orbiting highways”). In particular, for the Low Earth Orbit (LEO) region, a natural eccentricity growth can be leveraged in order to reenter to the Earth's atmosphere at a lower Δv-budget.The numerical cartography of the region has been proven from a theoretical perspective, on the basis of a frequency analysis focused on solar radiation pressure and lunisolar perturbations and on dynamical systems theory tools. In this work, we summarize the whole study concerning the dynamics that characterizes the LEO region in the long-term, by giving a comprehensive picture of the theoretical findings together with their possible exploitation for the debris mitigation. The efficiency of the “de-orbiting highways” is tested and validated with a “thought experiment” by means of long-term propagation of a population of objects stemming from a specific traffic launch. It is shown how the de-orbiting corridors could be very effective in removing the majority of objects from the high LEO region at the end-of-life, thus contributing to the stabilization of the space debris environment, in particular for high-altitude spacecraft.