Irish CubeSat proves wave based control for precise in orbit pointing

Irish CubeSat proves wave based control for precise in orbit pointing
by Sophie Jenkins
London, UK (SPX) Aug 20, 2025

EIRSAT-1, Ireland's first satellite, has validated an onboard Wave-Based Control payload that enables accurate attitude control in orbit. Developed at UCD's School of Mechanical and Materials Engineering, the software-led experiment demonstrates advanced manoeuvring techniques on a live spacecraft rather than solely in simulation.

Engineering Manager for EIRSAT-1 and UCD control systems expert Dr David Mc Keown said: "This achievement marks a major milestone for the group in deploying advanced control systems in space. The team has demonstrated that a novel control strategy can operate reliably in orbit and pave the way for developing satellite orientation control for missions with tight constraints, such as optical communications."

Across its two year mission, the team recorded motion data from onboard sensors. The CubeSat's magnetorquers steer the craft by interacting with Earth's magnetic field. This method is robust and power efficient but cannot by itself achieve the fine pointing needed for demanding applications.

To bridge that gap, UCD collaborated with Carnegie Mellon University on a new control algorithm. The approach spins the satellite about a principal axis to create gyroscopic stability, like a top. From this stable state, the controller nudges the attitude progressively toward any chosen target direction.

Testing over three consecutive orbits confirmed successful spin up and pointing accuracy within a few degrees. Control paused briefly, as designed, during eclipse and when Sun and geomagnetic alignment limited sensor quality. Chief Engineer Dr Joseph Thompson said: "We were delighted to see the satellite respond exactly as planned. It's a real validation of years of hard work and rigorous testing by the team, and we're very proud of the result."

The demonstration advances research in autonomy and onboard intelligence for small spacecraft. UCD PhD researcher Fionn Gibson Kiely said: "It's incredibly rewarding to see it perform so well in orbit. It's proof that our approach works in the harsh, unpredictable conditions of space."

Fellow UCD PhD student Bas Stijnen is using the same dataset to refine techniques that estimate a satellite's inertial properties. He said: "This data gives me a unique opportunity to test and refine my algorithms. It's a crucial step towards enabling more autonomous and intelligent CubeSats in future missions."

The work aligns with the National Space Subsystems and Payloads Initiative, a UCD-led program launched in March 2024 with over EUR 7.9 million from Ireland's Disruptive Technologies Innovation Fund. NSSPI employs model-based design and hardware-in-the-loop testing to accelerate next-generation satellite control systems.

Dr David Mc Keown, who also directs NSSPI, said: "High-precision satellite pointing is critical for the performance of complex systems such as optical communications, where even tiny misalignments can mean the difference between a strong link and no link at all. Through NSSPI, we are combining optical systems expertise with UCD's advances in satellite control to help ensure the next generation of space missions can achieve the accuracy and reliability these technologies demand."