Trade-off study on large constellation de-orbiting using low-thrust and de-orbiting balloons

This paper conducts a trade-off study on large constellation de-orbiting by using low-thrust and de-orbiting balloons. A novel de-orbiting strategy is proposed: the low-thrust propulsion is firstly used to actively de-orbit the satellites to de-orbiting corridors, and the de-orbiting balloons are then de-ployed to enhance the passive de-orbiting, driven by the resonances of natu-ral perturbations. The study is conducted via two layers - the first layer is designing the low-thrust trajectories for a single satellite; the second layer is conducting the trade-off analysis for a large constellation. In the first layer, a near time-minimum steering law, which can directly be applied to each sat-ellite from a constellation, is developed by using the theory of extrema; to reduce the computation load, the secular variations of the orbital elements are derived by using the orbital averaging technique. In the second layer, three figures of merit - coverage performance, fuel consumption, and total time to de-orbit - are discussed, and maps are drawn in colour as a function of constellation locations; by reading the maps, the trade-off analysis is con-ducted and a cost-efficiency approach is employed to identify the feasible constellation locations that fulfil various requirements.