Modeling and Analysis of The Deployment of a Tethered Satellite System

The use of Tethered Satellite Systems (TSS) has emerged as an attractive alternative for space-based radar sounding missions. Recent studies have demonstrated that a TSS enables the realization of large antenna apertures while reducing the propulsion requirements typically associated with traditional Formation Flying. Although this solution can significantly enhance sensing performance, it is inherently affected by dynamical instability, which makes the analysis of its dynamics and deployment phase an interesting aspect for system design. To this end, the research begins with the formulation of a comprehensive mathematical model relying on two of the main modeling methods for Tethered Satellite Systems: the rod model and the discrete model. Subsequently, the numerical simulation framework is introduced and studied to enable systematic simulation of the system’s dynamics across different configurations and operational environments. After an initial analysis of the dynamics of the TSS at a constant tether length, attention is shifted to the deployment process, highlighting the difficulties associated with this phase. In particular, the free system’s deployment along the radial, along-track, and cross-track directions is investigated. Subsequently, for each of these strategies, a preliminary control analysis is performed on the rod model, and relative control accelerations are derived and subsequently applied to the higher-fidelity system representation using the discrete model. This approach provides a comparison of each deployment strategy, highlighting both the stability challenges and the control resources associated with each option. Beyond providing practical guidelines for TSS mission design, the results establish a preliminary foundation for deeper study on control strategies for the deployment phase.