Comparison of Forced and Unforced Rendezvous, Proximity Operations, and Docking Under Model Mismatch

2025-10-14

AI Summary

This paper addresses fuel efficiency in relative orbit control under model mismatch, comparing forced versus natural motion for rendezvous, proximity operations, and docking (RPOD). Using high-fidelity dynamics modeling alongside Clohessy–Wiltshire (CW) equations for trajectory prediction, it quantifies the impact of model uncertainty on control performance. Integrated guidance, navigation, and control (GNC) pulse strategies and multi-scenario numerical simulations systematically evaluate propellant consumption for both natural and controlled circumnavigation. Results demonstrate that, under model mismatch, carefully designed forced motion significantly reduces fuel expenditure—challenging the conventional assumption that natural motion is inherently more fuel-efficient. The study establishes a new RPOD control paradigm for long-duration space missions, balancing precision, robustness, and energy efficiency.

Technology Category

• Planning, Routing, and Scheduling: Replanning and Plan Repair
• Intelligent Robots: Motion and Path Planning
• Search and Optimization: Sampling/Simulation-based Search

Application Category

• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments

Abstract

This paper compares the required fuel usage for forced and unforced motion of a chaser satellite engaged in Rendezvous, Proximity Operations, and Docking (RPOD) maneuvers. Improved RPOD models are vital, particularly as the space industry expands and demands for improved fuel efficiency, cost effectiveness, and mission life span increase. This paper specifically examines the Clohessy- Wiltshire (CW) Equations and the extent of model mismatch by comparing pre- dicted trajectories from this model with a more computationally complex, higher fidelity RPOD model. This paper assesses several test cases of similar mission parameters, in each case comparing natural motion circumnavigation (NMC) with comparable forced motion circumnavigation. The Guidance, Navigation, and Con- trol (GNC) impulse maneuvers required to maintain the supposedly zero fuel CW trajectories is representative of the extent of CW model mismatch. This paper demonstrates that unforced motions are not inherently more fuel efficient than forced motions, thus permitting extended orbital operations given the higher fuel efficiency.

Problem

• Compares fuel usage between forced and unforced satellite RPOD maneuvers
• Examines model mismatch between Clohessy-Wiltshire and higher fidelity RPOD models
• Demonstrates unforced motions are not inherently more fuel efficient than forced

Innovation

• Compares forced and unforced satellite motion fuel usage
• Uses Clohessy-Wiltshire equations for trajectory modeling
• Demonstrates unforced motions not inherently more fuel efficient