Ph.D. Thesis Proposal

Sonal Mehta

(Faculty Advisor: Professor Dimitri Mavris)

"A Coupled Operator-Policy-Environment System of Systems with Empirical Behavioral Characterization and Adaptive Policy Pathways for Quantitative Space Sustainability Under Deep Uncertainty"

Friday, June 5

8:00 - 9:00 a.m.

Weber, CoVE

Abstract:

As humanity's reliance on satellite-based infrastructure grows, the long-term sustainability of the orbital environment has become a defining policy challenge. The orbital regime is a System of Systems (SoS) governed by three managerially and operationally independent systems, namely satellite operators, regulatory bodies, and sensor networks, that jointly shape the shared population of objects in orbit. Yet the evolutionary models that currently inform sustainability policy do not represent it as such. Operator behavior is collapsed into species-level exogenous scalars set by the modeler, policy enters only as exogenous hand-tuned parameter changes, and the coupling between systems is absent from the analysis pipeline. A policy's evaluated impact therefore reflects the modeler's assumptions about operator behavior more than the policy's actual effect on that behavior, and by extension, on the environment.

This thesis develops a coupled operator-policy-environment SoS framework that current practice lacks by drawing on Multi-Sector Dynamics principles for the managerially independent sectors, bidirectional human-environment coupling, heterogeneous actors, long horizons, and deep uncertainty that characterize this problem class. The framework is built in three research areas. First, three on-orbit operator behaviors, mission lifetime, post-mission disposal compliance, and collision avoidance effectiveness, are characterized empirically at operator-class resolution, producing distributions that respond to environmental and policy state rather than fixed scalars. In parallel, an index-based policy model composed of indicators and sub-indicators is developed to represent the policy system. Second, these behavioral models are integrated to form a satellite operator system implemented as an Agent-Based Model, which is then coupled with the policy system and an open-source debris-evolution propagator. Within the resulting framework, operator decisions, policy state, and the orbital environment endogenously co-evolve over the projection horizon. Third, the coupled framework is evaluated through Decision-Making-under-Deep-Uncertainty (DMDU) methods. Metrics are chosen so that environmental outcomes can be traced back to the specific policy levers that produced them. Those metrics then guide adaptive pathways of policy implementation that keep the system state sustainable, enabling assessment of multiple candidate pathways rather than committing to a single trajectory of policy evolution.

Committee:

• Dr. Dimitri Mavris (advisor), School of Aerospace Engineering
• Prof. Thomas González Roberts, Daniel Guggenheim School of Aerospace Engineering, Sam Nunn School of International Affairs
• Prof. Mariel Borowitz, Sam Nunn School of International Affairs
• Dr. Tristan Sarton Du Jonchay, Daniel Guggenheim School of Aerospace Engineering

• Dr. Madeline Bowne, Telesat