The Greek cubesat ERMIS-3, built at the University of Athens, has established a laser link with a ground station. This is Greece's first optical communication channel with a satellite in low Earth orbit. The link was made just a few weeks after the spacecraft was put into operation.
ERMIS-3 is an 8U cubesat, that is, a small satellite the size of several one-liter boxes. The link was provided by optical terminals from the Lithuanian company Astrolight. The project was supported by the European Space Agency (ESA).
Unlike conventional radio communication, laser transmission uses a narrow beam. This allows large amounts of data to be transmitted, but requires high precision: the satellite moves at several kilometers per second, and the beam must be kept on the receiver at all times. In addition, clouds can completely block the signal, and atmospheric turbulence can degrade its quality.
The satellite linked with the HolOGS-1 ground station, which was developed by Aristotle University of Thessaloniki. The rapid establishment of the link confirmed one of the mission's main objectives: precise pointing, acquisition and tracking (PAT).
ERMIS-3 was launched on March 30, 2026, together with ERMIS-1 and ERMIS-2. The mission is part of the Greek national space program, which ESA carries out on behalf of the Greek government. The spacecraft carries the ATLAS-1 optical terminal from Astrolight. ESA helped with testing and alignment of the optics at its ESTEC center in the Netherlands.
According to ESA project manager Frederic Rouenel, the success demonstrates that Europe can create advanced technologies through cooperation between industry, science and institutions. Professor Vaios Lappas and Antonis Paschalis, lead researchers of ERMIS, noted that ERMIS-3 is one of Europe's most advanced cubesats, and that the laser terminal opens new possibilities for secure communications by small satellites. Professor Kleomenis Tsiganis of Aristotle University stressed that this is Greece's first successful optical channel with a low-orbit satellite, and with a Greek spacecraft at that.
Laser communication links could help cope with the growing volume of data from Earth observation, where high-resolution and hyperspectral images need to be transmitted. However, this is still a technology demonstration, not an everyday service.