First-of-its-kind optical ground station commissioned in Luxembourg to demonstrate international quantum-secure communications 

26 Jul 2026

A new optical ground station (OGS), developed under the European Space Agency (ESA) and built by HITEC in a consortium led by Starion Luxembourg, has been commissioned in the presence of Luxembourg’s Ministers of Economy and Defence, Lex Delles and Yuriko Backes, the Luxembourg Space Agency, and representatives of ESA.

The OGS, located in Windhof, Luxembourg, will help to test an ultra-secure, international communications network using cutting-edge Quantum Key Distribution (QKD) and Post-Quantum Cryptography (PQC) technologies. The purpose-built network is designed to address Europe’s strategic imperative to elevate its institutional and commercial cybersecurity.

Developed by ESA’s International Use cases for Operational QKD Applications and Services (INT-UQKD) partnership project, through the Agency’s Advanced Research in Telecommunications Systems (ARTES) programme, the OGS is part of a solution addressing two challenges to current space-based communications. On the one hand, the Radio Frequency (RF) spectrum, widely employed for satellite communications, is vulnerable to disruption and interception. On the other, the advent of quantum computing poses an urgent risk to cryptographic techniques used to secure critical terrestrial and space-based data communication services and IT infrastructure.

This technological vulnerability to telecommunications poses a clear socio-economic risk and underlines the strategic importance of securing satellite communications from current and future threats. In order to achieve an elevated degree of security and safeguard communications against quantum computers, INT-UQKD integrates both QKD and PQC into existing communications networks. This integrated approach will help to remove single points of vulnerability and increase resilience against complex attempts to disrupt or intercept encryption keys.

QKD services offer a strong layer of security by creating encryption keys using the quantum properties of light. These keys are established between two trusted ‘nodes’, allowing them to respectively encrypt and decrypt the information. Whereas this can be done over land via optic fibre, applying this method across oceans requires satellites to be used as trusted nodes connected by laser terminals in lieu of fibres.

The Windhof OGS boasts a versatile design tailored to QKD and optical satellite communications. Rather than adopting alt-azimuth or equatorial mounts, traditionally employed for optical astronomy equipment, the OGS adopts an X/Y axis design carried over from HITEC’s work on RF ground stations. This design is more advantageous for tracking fast-moving satellites in the sky, in particular at low angles of elevation over the horizon. In addition, this mount helps to overcome a reversal in the polarity of the optical link which occurs as the satellite reaches its zenith, a specific challenge for optical communications that is resolved by allowing the optical terminal to rotate accordingly. The OGS will test this configuration in tandem with the experimental SpeQtral-RAL Space Quantum Communications Satellite, launched in late 2025, to establish a QKD link with Singapore and demonstrate its practicality for commercial applications.

INT-UQKD represents the convergence of multiple areas of technical expertise under ESA’s Advanced Research in Telecommunications Systems (ARTES) 4.0 programme: it is implemented as a partnership project with industry, as part of the Space Systems for Safety and Security (4S) strategic programme line (SPL), and managed by the Optical and Quantum Communications – ScyLight SPL. This project is the fruit of an international collaboration between ESA and the Luxembourg Space Agency (LSA), the Belgian Science Policy Office (BELSPO), the Canadian Space Agency (CSA), with contributions from SpeQtral and the National Space Agency of Singapore (NSAS). The latter have financed and managed the space segment of this project.

The commissioning of the Windhof OGS is part of the first phase of INT-UQKD, supported by POST Luxembourg, HITEC (Luxembourg), the Interdisciplinary Centre for Security, Reliability and Trust (SnT) of the University of Luxembourg, evolutionQ (Canada) and SpeQtral (Singapore). In this phase, the project will deploy a standalone hybrid terrestrial and space quantum communication infrastructure across Luxembourg, Belgium and Singapore to demonstrate a QKD service on a global scale.