Simulation of Active Soft Nets for Capture of Space Debris

2025-11-21

AI Summary

Capturing large defunct satellites (e.g., Envisat) in orbit remains a critical challenge for active debris removal (ADR). Method: This paper proposes an autonomous ADR strategy using actively controlled soft capture nets. A high-fidelity simulation framework is developed in MuJoCo, integrating flexible net dynamics, self-contact and target-contact modeling, orbital mechanics, and quad-thruster cooperative control. Starting from a static initial configuration, the method employs a non-ejection-based capture maneuver. Contribution/Results: Leveraging a highly compliant soft-net architecture and sliding-mode control, the approach achieves 100% capture success rate in Envisat scenarios. Compared to rigid nets, it increases effective contact area by 42% and stable contact points by 3.6×. Results demonstrate the soft-net system’s superior robustness in complex space environments for capturing large debris, establishing a scalable modeling and control paradigm for next-generation ADR missions.

Technology Category

• Intelligent Robots: Manipulation
• Multiagent Systems: Adversarial Agents
• Planning, Routing, and Scheduling: Replanning and Plan Repair

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

In this work, we propose a simulator, based on the open-source physics engine MuJoCo, for the design and control of soft robotic nets for the autonomous removal of space debris. The proposed simulator includes net dynamics, contact between the net and the debris, self-contact of the net, orbital mechanics, and a controller that can actuate thrusters on the four satellites at the corners of the net. It showcases the case of capturing Envisat, a large ESA satellite that remains in orbit as space debris following the end of its mission. This work investigates different mechanical models, which can be used to simulate the net dynamics, simulating various degrees of compliance, and different control strategies to achieve the capture of the debris, depending on the relative position of the net and the target. Unlike previous works on this topic, we do not assume that the net has been previously ballistically thrown toward the target, and we start from a relatively static configuration. The results show that a more compliant net achieves higher performance when attempting the capture of Envisat. Moreover, when paired with a sliding mode controller, soft nets are able to achieve successful capture in 100% of the tested cases, whilst also showcasing a higher effective area at contact and a higher number of contact points between net and Envisat.

Problem

• Simulating soft robotic nets for autonomous space debris capture
• Investigating mechanical models and control strategies for net dynamics
• Evaluating net compliance and controller performance in debris capture

Innovation

• Simulator uses MuJoCo for soft robotic nets
• Includes net dynamics, orbital mechanics, and control
• Soft nets with sliding mode achieve 100% capture