Evaluating the environmental sustainability of small satellites and large constellations in LEO

The dramatic surge of small satellite launches during the last few years and the current plans envisaging the deployment of very large constellations in LEO, some consisting of thousands of spacecraft, raised a growing concern regarding the long-term sustainability of the near-Earth space environment with the present-day guidelines recommended by the IADC. Assessing the impact of the proliferation of small satellites and large constellations is therefore a modeling priority, in order to evaluate if additional, and more stringent, mitigation measures might be needed. The task is quite complex, because traffic models and constellation deployment plans are, of course, subject to sudden changes, driven by economic and technical issues. The same applies to technological developments and breakthroughs, which could change completely the nature of space systems, as in part is already happening with the flourishing of mini, micro and nano-satellites. A simplified analytical model was therefore developed to provide quick answers and guesses for preliminary evaluations of the potential criticality of small satellites and large constellations.