Interaction of the Satellite Constellations with the Low Earth Orbit Debris Environment

The effect on the orbital debris environment of several satellite constellations, to be launched and maintained in LEO over the next decades, has been analyzed with the SDM software system, including updated initial conditions and traffic model scenarios. Over 50 years, the single most effective mitigation measure to limit the growth of 1-10 cm debris is found to be the interruption of in-orbit explosions of satellites and upper stages. But if no additional mitigation policy were to be adopted by constellations owners and operators, a significant increase of decimeter-sized objects would be observed and in 3040 years the exponential growth of centimeter-sized debris might be triggered by collisions. However, if further mitigation measures, such as the de-orbiting of upper stages and spacecraft at the end of their operational life, were implemented, the impact on the debris environment of the proposed constellations would be minimal in the next 50 years, with a stabilization of the debris population at decimeter sizes and a decrease at centimeter sizes. On the other hand, our results indicate that the long term effect (over one century or more) of concentrating so many spacecraft in regions of space already crowded by large objects is not negligible, and that the risk of a collisional chain reaction will be increased significantly in several altitude bands.