Regulating Orbital Decay through Passive Thermochromism in PMPEs for Orbital Debris Remediation

Current state-of-the-art techniques for small debris (<1 cm) remediation use dust clouds composed of small grains to induce artificial drag and deorbit debris. By passively controlling the variation of particle properties, it is possible to harness external forces to steer orbital motion. Programmable Metamaterial Particle Ensembles (PMPEs) could allow for more precise regulation of semi-major axis variations, hence improving management of radial dispersion, along-track dispersion, and orbital decay compared to inert dust clouds. This work investigates how solar radiation pressure (SRP) can be utilized for orbit control by regulating optical properties according to temperature. Preliminary studies of the PMPE design space were performed using a thermo-orbit model to assess particle trajectories and temperature responses, and to begin informing the requirements for orbital debris removal technology development. Initial results demonstrated the intended effects of PMPEs, showing that variations in optical properties with temperature can induce SRP asymmetry, thereby enabling semi-major axis control over successive orbits. Subsequent analysis identified performance metrics, such as volumetric heat capacity, which could inform the optimal selection of materials to prolong the duration of asymmetric SRP induction. Further studies explored design parameters that maximize control authority over decay rates for specific test cases. In the orbit range of interest for small debris remediation (800-1000 km), we found that PMPEs have the capability to either cancel out or double the natural decay rates, allowing for operators to optimize interactions with debris. This research highlights the promising potential of PMPEs for innovative passive orbit control solutions, paving the way for further advancements in space debris mitigation.