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EIRSAT-1, Ireland's first satellite, has successfully tested an advanced onboard control system that allows it to orient itself accurately in space. The breakthrough was achieved using a payload called Wave-Based Control (WBC), a software platform designed by a team at UCD School of Mechanical and Materials Engineering to test new satellite maneuvering techniques while in orbit.

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."

During its two-year mission, the team collected data on the satellite's movements via onboard sensors. The CubeSat uses electromagnets to adjust its orientation by interacting with Earth's magnetic field which, while reliable and energy efficient, are insufficient by themselves to enable precise pointing of the satellite.

To overcome this challenge, the team developed a new control algorithm in collaboration with Carnegie Mellon University. The software causes the satellite to spin around one of its main axes, providing stabilization in a manner similar to a spinning top. Once stabilized, the satellite can gradually reorient itself towards a desired target direction.

Data collected during testing over three orbits showed that the satellite successfully spun up and achieved pointing accuracy within just a few degrees. Some short periods without control occurred when the satellite was in Earth's shadow or when sensor readings were limited by the alignment of the sun and Earth's magnetic field. During these times, the satellite paused its maneuvers as expected.

Chief Engineer of EIRSAT-1, 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 successful test also marks a significant step forward for research into satellite autonomy and onboard intelligence. Fionn Gibson Kiely, a Ph.D. student at UCD who helped develop and implement the algorithm, 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 Ph.D. student Bas Stijnen is using the mission data to develop advanced onboard techniques to 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."

This latest success directly supports the goals of the National Space Subsystems and Payloads Initiative (NSSPI), a UCD-led program launched in March 2024. NSSPI is developing next-generation satellite control systems using model-based design and hardware-in-the-loop testing to accelerate innovation in Irish space technology.

Dr. Mc Keown is also Director of NSSPI. He 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."