On the Social Cost of Orbital Debris

Orbital debris represents a global environmental externality in outer space, akin to terrestrial environmental externalities, imposing a social cost on humanity. Accurately quantifying this social cost is crucial for designing and implementing effective debris mitigation policies. This paper estimates the social cost of orbital debris (SCOD) using a methodology inspired by climate-change economics, particularly the approach used to calculate the social cost of carbon (SCC) through projections derived from integrated assessment models (IAMs). We introduce an IAM that links economic activity with space activity, modeling orbital debris emissions as a function of launches and collisions. The model generates optimal trajectories for orbital debris emissions and consumption, which are then used to estimate the SCOD. Our results indicate that the SCOD is approximately $84,200 per piece of debris larger than 1 cm for the year 2023 (in international US dollars), based on a 1.5% social discount rate and an intertemporal marginal consumption rate of 1.5.