Modelling the Dynamics of the Space Debris Environment

A full understanding of the dynamics of objects in the circumterrestrial environment is a fundamental step for the accurate modelling of the space debris population. Even more now, in a period of huge changes in the space traffic, with the continued accumulation of artificial objects around our planet and the plans of exploitation of new orbital regions. A short review of the main perturbative effects which are most important for the dynamics in different regions of the Earth orbit is given. Then the focus is moved to a review of some results obtained in the last years on the resonance effects in Earth orbit and on how these resonances could be exploited as transport mechanisms to remove spacecraft at the end-of-life. The analogies with the dynamics of the small bodies in the Solar System is shown to highlight the importance of the cross-fertilization between these two close-by research fields. Finally, some remarks are given on the collective behavior of large ensembles of objects by studying the dynamics of the cloud of fragments produced by in-orbit fragmentations. In particular, the complex evolution of the collision risk following a fragmentation of a satellite within a multi-plane constellation is discussed.