Xairos UK, Ltd., a UK-based quantum technology company, has been selected as a subcontractor by Raymetrics S.A. and the European Space Agency (ESA) to develop a quantum receiver for the Observatories to Optical Ground Stations (Obs2OGS) project. The initiative is part of ESA’s Greek Connectivity Recovery and Resilience programme, under the agency’s Connectivity and Secure Communications directorate. The project aims to upgrade three Greek astronomical observatories—Helmos Observatory operated by the National Observatory of Athens (NOA) in the Northern Peloponnese, Holomontas Observatory managed by Aristotle University of Thessaloniki (AUTH), and Skinakas Observatory run by the Institute of Astrophysics at the Foundation for Research and Technology-Hellas (FORTH) in Crete—into optical ground stations (OGS). These upgraded facilities will support secure quantum communication by receiving quantum encryption keys from the EAGLE-1 satellite. Xairos will provide critical quantum receiver capabilities for one of the three sites, enabling secure, high-speed quantum key distribution between space and ground. This advancement is central to Greece’s national quantum communication initiative and strengthens Europe’s strategic infrastructure for secure data transmission. Raymetrics leads the consortium, leveraging its expertise in atmospheric LIDAR systems and AI-driven environmental monitoring technologies. The company’s proprietary algorithms based on artificial intelligence and machine learning enable precise atmospheric characterization, essential for optimizing optical communication links between satellites and ground stations. The Obs2OGS project underscores ESA’s commitment to advancing secure, resilient space-based communications across Europe. By integrating quantum technologies into ground infrastructure, the initiative supports the broader vision of a quantum-secure European communication network. Xairos is focused on building a global, resilient space-based timing architecture using Quantum Time Transfer (QTT), a protocol developed and patented by the company. QTT enables ultra-precise and tamper-resistant time synchronization—vital for critical infrastructure including transportation systems, financial networks, data centers, and power grids. The company is commercializing QTT to deliver next-generation Position, Navigation, and Timing (PNT) solutions with unmatched accuracy and security. This collaboration marks a significant milestone in the integration of quantum technologies into operational space systems and highlights the growing role of UK-based innovators in Europe’s space and quantum ecosystems.