China develops crystal that could enable GPS-free navigation for submarines

Chinese researchers have developed a new crystal that could one day help submarines, missiles, and spacecraft navigate without relying on GPS. The material is designed to generate extremely short-wavelength ultraviolet light needed for advanced thorium nuclear clocks—a next-generation timekeeping technology considered far more precise than today’s atomic clocks.  

Navigation systems like GPS depend on highly accurate timing signals from satellites. If those signals are jammed, spoofed, blocked underwater, or unavailable in deep space, navigation becomes difficult. Nuclear clocks could solve that problem by keeping ultra-precise time internally, allowing vehicles to determine position through dead reckoning and other onboard methods.  

The new fluorinated borate crystal reportedly converts laser light to 145.2 nanometers, surpassing the previous benchmark of around 150 nanometers. Scientists say this is an important step toward the 148.3 nanometer wavelength needed to activate thorium-229 nuclei for practical nuclear clocks.  

If fully developed, the technology could reduce dependence on satellite navigation for military systems such as submarines and missiles, while also helping spacecraft navigate autonomously far from Earth. However, this remains a research-stage breakthrough rather than an operational system.