Design and Dynamic Analysis of a Tethered-Net-Based Space Debris Capture System with Winch-Driven Closure Mechanism

This study presents a design and performance analysis of a tethered-net-based space debris capture system using multibody dynamic simulation. The increasing accumulation of space debris in Low Earth Orbit (LEO) necessitates reliable capture mechanisms capable of handling non-cooperative targets with positional and velocity uncertainties. To address this, a node-based net model was developed, in which the net structure is represented by interconnected spring-damper elements to capture large deformation and nonlinear behavior. The dynamic analysis was conducted using the commercial multibody dynamics software RecurDyn, considering key design parameters such as ejection distance, angle, and velocity. The results show that the net deployment characteristics are strongly influenced by ejection conditions. An optimal configuration was identified at an ejection angle of 18° and an ejection velocity of 10 m/s, satisfying both deployment performance and the allowable tension limit of 300 N. The proposed capture mechanism enables the net to fully pass over the target before activating a winch to reel in the pulling rope, thereby minimizing impact forces and improving capture stability. Furthermore, the capture performance was quantitatively evaluated under relative position and velocity uncertainties. The maximum allowable lateral velocity was derived as a function of the available capture margin, yielding approximately 1.25 m/s without positional error and 0.30 m/s with a 1 m positional offset. These results provide practical design guidelines for net-based space debris capture systems and demonstrate the robustness of the proposed approach under realistic operational conditions.