SWF Helps Develop New Model to Assess Policy Proposals for Space Sustainability

Friday, September 29, 2023

In September 2022, Secure World Foundation was part of a team that won a NASA grant to study the economic, social, and policy issues associated with space sustainability. The goal of our study was to develop an integrated assessment model (IAM) that could be used to better evaluate the various public policy proposals to deal with space sustainability challenges related to large constellations, orbital debris, and space traffic management. The research was led by Professor Akhil Rao from Middlebury College and Professor Daniel Kaffine from the University of Colorado-Boulder. SWF Director of Program Planning Dr. Brian Weeden contributed policy-related aspects of the work.

On September 27, 2023, our team joined the others in briefing NASA on our results. The end result of our effort is the Orbital Debris Propagators Unified with Economic Systems (OPUS), which is a unique approach that combines a physics-based model of the orbital environment with an economic model of space actor behavior. In this way, OPUS can not only evaluate how policy proposals will effect the rate of collisions and orbital congestion, but also how satellite operators will react to the changing economic incentives and risk factors. Understanding this behavior is critical for evaluating the efficacy of public policies because there may be cases where unforeseen behavior causes suboptimal or even counterproductive results to the policy goal.

In its initial incarnation, OPUS takes in a wide range of user-defined variables and then simulates the impact on the orbital environment using one of two different orbital propagators and an open-access conditions economic model, which reflects the commons nature of outer space. Users can define various constellation sizes and locations, the number and rate of non-constellation satellites being launched, and a host of economic variables such as launch cost, delta-v cost, and satellite depreciation. By adding in the economic behavior to the model, we find multiple behaviors that emerge in the output that are different from what would be obtained from a purely physics-based approach. In this way, OPUS can help policymakers evaluate not only the impact policy proposals might have on orbital collision risk but also economic welfare and space sustainability.

A presentation overview of OPUS can be found here. A detailed technical paper can be found on arxiv.org and all the underlying code and scripts is freely available on Github. The team hopes that these tools will be of use to other researchers and policymakers as the community continues to tackle the challenge of space sustainability.

For more information, please contact Dr. Brian Weeden.