Space Mission Sustainability Leveraging Picard-Chebyshev Methods and Optimal Control

Spacecraft sustainability is crucial for the long-term exploration and utilization of space. As humanity ventures further from the Earth, responsible and sustainable management of space assets becomes imperative to ensure the preservation of the space environment. In-space servicing missions enable the extension of the operational life of satellites and other spacecraft, which reduce the frequency of new launches and minimize space debris. In this talk, three enabling technologies are presented to address challenges associated with accurate and efficient optimal trajectory design for in-space assembly. The first involves using Picard-Chebyshev methods for accurate and efficient trajectory propagation of low-thrust, fuel-optimal trajectories that contain bang-bang thruster switches and require a high-fidelity spherical harmonic gravity model, which is expensive to compute. The second involves introducing thruster pointing constraints directly into the indirect optimal control formulation such that fuel-optimal trajectories can be flown in close proximity to the client spacecraft without the thruster plume contaminating delicate sensors onboard the client. The third involves incorporating inter-agent anti-collision constraints directly into the indirect optimal control problem considering 6-DOF motion, thus ensures that high-fidelity fuel-optimal solutions are obtainable while ensuring constraint satisfaction. The abovementioned fundamental contributions are an important step towards successful, large-scale and routine in-space servicing and assembly missions.

Speaker: Robyn Woollands, University of Illinois, Urbana-Champaign