New Publication: A Coupled Analytical-Simulation Approach to Redundant Small Spacecraft AOCS

Designing fault-tolerant thruster systems for the next generation of in-orbit servicing

Ice2Thrust has published a new scientific paper presenting a coupled analytical and simulation framework for designing the Attitude and Orbit Control Systems (AOCS) of small spacecraft — with redundancy and real-world dynamics built in from the very first design step. The paper was presented at SmallSat Europe 2026 in Amsterdam (26–28 May 2026).

A new generation of missions — close-proximity operations, docking, and in-orbit servicing — is reshaping what small satellites are expected to do. Beyond simply holding their orientation, today’s spacecraft increasingly need precise control over both rotation and movement in every direction (six degrees of freedom). Cold-gas thruster arrays are central to delivering this fine control, but designing them well is difficult: they must perform during long, sustained manoeuvres and short, precise pulses, all while staying reliable even if an individual thruster fails.

A key contribution of the study is rethinking how redundancy is built into thruster design. Existing approaches focus mainly on impulsive performance and don’t capture this fuller picture. The new work reformulates established fault-tolerant design methods so that a spacecraft always retains enough control authority to complete close-proximity and docking operations — even with a thruster offline. A modular simulation stack then adds realistic effects such as valve transients and small-nozzle efficiency, and integrates a Reinforcement Learning guidance module for autonomous docking.

Using a genetic algorithm, the team identified an optimised thruster layout and verified it on a rendezvous and servicing scenario — an in-orbit servicing demonstration of Water Electrolysis Propulsion (WEP). The optimised configuration achieved a 15.7% reduction in thruster on-time, pointing to meaningful gains in efficiency and propellant economy over conventional impulsive-centric design.

The publication establishes a baseline for AOCS hardware development within the Ice2Thrust EIC Pathfinder project, which proposes WEP as a safe, non-toxic, high-performance, and refillable alternative to conventional propulsion. By embedding redundancy and realistic system behaviour into the design from the outset, the approach helps deliver spacecraft that are robust and ready for demanding mission-extension applications — a cornerstone for sustainable, serviceable, and long-lived in-space infrastructure.

Authors:

• Tomas Mrazek, Researcher, Technical University of Munich.
• Aman Arora, Researcher, University of Luxembourg.
• Matteo El Hariry, Researcher, University of Luxembourg.
• Yasin Kale, Researcher, Technical University of Munich.
• Prof. Chiara Manfletti, Principal Investigator, Professor for Space Mobility and Propulsion (Supervisor), Technical University of Munich.

📄 Read the full paper here: A Coupled Analytical-Simulation Approach to Redundant Small Spacecraft AOCS within the Ice2Thrust project: https://zenodo.org/records/20138426