OpSTAR: Lighting the Path to the Future of PNT

In recent years, society has undergone a digital transformation. Today, the invisible foundation of our modern society actually extends beyond pure digital data-it hinges on integrating data with spatial and temporal information. Positioning, navigation and timing (PNT) systems serve as the backbone of countless critical functions from synchronizing stock exchanges and energy grids to guiding aircraft, shipping fleets, and emergency responders. The ability to determine the "where" and the "when" with high precision is no longer optional-it has become a crucial enabler for responding to key societal challenges. For decades, space-based PNT systems, such as Europe's Galileo, have provided global, reliable PNT services. These systems bring significant socio-economic, political and strategic benefits by enhancing efficiency, safety and productivity across various sectors. Acknowledging the evolving geopolitical landscape, the growing ecological challenges posed by climate change, and the rapidly increasing reliance of the economic and defence sectors on GNSS, the demands on current and future PNT systems are rising dramatically. Considering these ever-increasing demands and, on the downside, the growing threats to critical PNT infrastructure, Europe faces a strategic decision to either maintain the current PNT capabilities and risk European PNT becoming obsolete, or embracing novel technologies to ensure its leadership in an evolving world. Among those novel technologies that can offer improved performance, greater autonomy, resilience and extended reach, laser-based connectivity for optical inter-satellite links (OISL) and optical ground-to-space links (OGSL) stand out as the most promising technology for PNT systems in the near to mid-term future. Already revolutionizing the field of satellite communications, optical link technologies are now poised to transform PNT systems and applications. The key question is not whether this transition to optical PNT will happen, but when and under whose lead.