ERMIS-3, an 8U CubeSat developed by the National and Kapodistrian University of Athens, has successfully established a challenging laser link with an optical ground station. This demonstration, which occurred only weeks after the satellite's commissioning, represents a significant step in validating optical communications for small satellites. The mission is supported by the European Space Agency (ESA) and utilizes optical terminals developed by the Lithuanian company Astrolight.
This milestone marks Greece's first optical link with a Low Earth Orbit (LEO) satellite. Unlike conventional radio-frequency systems, optical links employ narrow laser beams to transmit data at high rates. However, this method is technically demanding as it requires precise pointing, acquisition, and tracking (PAT). The beam must be directed accurately toward a receiver while the satellite travels at several kilometers per second, with both terminals continuously tracking each other during limited communication windows. Additionally, atmospheric conditions such as clouds and turbulence can block or degrade the signal.
The satellite connected with the Holomondas Optical Ground Station (HolOGS-1) in Greece, which was developed by the Aristotle University of Thessaloniki. ERMIS-3 carries Astrolight's ATLAS-1 optical terminal, paired with a corresponding terminal at the ground station. The rapid establishment of this link demonstrated one of the mission's primary objectives: precise PAT capabilities.
Launched on March 30, 2026, alongside ERMIS-1 and ERMIS-2, ERMIS-3 is part of an in-orbit demonstration program testing communications technologies for small satellites. Optical links are seen as a potential solution for the growing volume of data generated by missions like Earth observation, where high-resolution and hyperspectral imagery must be transferred to the ground. ESA contributed technical expertise to the project, including environmental testing and optical alignment at its European Space Research and Technology Centre (ESTEC) in the Netherlands.
The mission is part of Greece's National Space Programme, implemented by ESA on behalf of the Greek government. Frederic Rouesnel, Head of the Resilience Initiatives Implementation Management Office at ESA, stated that this achievement demonstrates Europe's ability to deliver world-class innovation through cooperation between industry, academia, and institutions. He noted that for the first time, an 8U CubeSat from the University of Athens has established a laser link using a miniaturized terminal developed by Astrolight.
Professor Vaios Lappas and Antonis Paschalis, Principal Investigators of ERMIS, described the nanosatellite as one of the most advanced CubeSats developed in Europe. They highlighted that using the ATLAS-1 terminal has opened new capabilities for secure communications within the European ecosystem. Professor Kleomenis Tsiganis, Head of SSA and OGS activities at the Aristotle University of Thessaloniki, emphasized the significance of this milestone for optical communications in Greece, noting it is the first successful link with a LEO satellite from the Holomondas facility using a Greek space asset.
Sources: ESA Space News.