For decades, space-based PNT systems, such as Europe’s Galileo, have provided global, reliable PNT services. The key question is not whether this transition to optical PNT will happen, but when and under whose lead. Yet, the full promise of optical PNT cannot be immediately realized without real-world concept, technology validation and de-risking. All these benefits will be strengthened with PNT systems interconnected more precisely and resiliently than ever before via optical links. Building on this foundation, OpSTAR will contribute to developing an optical PNT standard with the long-term vision of supporting not only future EU PNT infrastructure, but also broader missions aligned with CCSDS standards.