Stable Portable Atomic clock for Reliable Timing And Navigation (SPARTAN)

A new UK-built atomic clock will use a low-cost frequency comb—a device that measures light waves with extreme precision—to replace the satellite-dependent timing systems that underpin modern navigation, communications, and defence. Today, GPS and other global navigation satellite systems (PNT) rely on signals from space that can be jammed, spoofed, or simply lost indoors or underground. SPARTAN aims to build a portable optical atomic clock that does not need a satellite link, using a frequency comb manufactured entirely within the UK supply chain. This removes reliance on foreign components and makes the technology cheaper and more robust. If successful, the clock could provide reliable timing for autonomous vehicles, power grid synchronisation, financial trading networks, and military operations—anywhere that losing a satellite signal causes disruption. The same frequency comb also enables advanced LIDAR and spectroscopy for defence and security applications, such as detecting chemical threats or mapping terrain without GPS. The project is applied engineering, not fundamental science. It takes existing optical clock and comb principles and turns them into a commercial product with a sovereign UK supply chain.