On 6 May 1964, scientists and engineers staged one of the earliest public demonstrations of satellite navigation concepts, illustrating how radio signals from satellites could be used to determine position on Earth. The demonstration consolidated theoretical work from the late 1950s and early 1960s on using time-coded radio transmissions and Doppler shifts from orbiting transmitters to fix locations, and helped shift the idea of space-based navigation from laboratory research to practical engineering development. Background Interest in satellite navigation grew rapidly after the launch of Sputnik in 1957, when observers noted that tracking the Doppler shift of that satellite’s radio signal allowed position estimation. In the following years researchers in several countries refined concepts for purposeful navigation satellites: precise timing, coded signals, and predictable orbits were identified as the key ingredients. Military and civilian engineers explored competing approaches—Doppler-based fixes from moving transmitters, and later systems that would use synchronized time signals to compute ranges. The 1964 demonstration The public demonstration on 6 May 1964 presented to attendees how signals transmitted from an orbiting satellite could be received at ground stations and processed to yield position information. Organizers showed practical aspects: receiving satellite transmissions, measuring signal timing and frequency shifts, and using those measurements with known orbital data to compute geographic coordinates. The event emphasized the feasibility of navigation from space for both maritime and airborne users, and illustrated potential civilian as well as military applications. Significance The demonstration did not invent the underlying physics, but it made the techniques tangible to policy makers, engineers, and potential users. By turning laboratory results into an operationally oriented presentation, the event helped accelerate funding and technical programs aimed at building operational satellite navigation systems. Within a decade, development work led to operational systems such as the U.S. Navy’s Transit (first operational around 1964 for precise navigation for submarines and ships) and later the U.S. Department of Defense’s Navstar GPS program, which began in the 1970s and achieved initial operational capability in the 1990s. The 1964 demonstration is therefore often cited as an important milestone in the transition from concept to implementation. Limitations and context Contemporary demonstrations and reports varied in technical detail and scope, and different teams emphasized different methods (for example Doppler-based fixes versus time-of-flight ranging). Sources from the era sometimes conflate demonstrations, laboratory tests, and the early operational availability of systems like Transit. While the 6 May 1964 demonstration was influential in public and technical discussions, it was one of several parallel efforts worldwide that collectively established the foundations for modern satellite navigation. Legacy The public demonstration helped legitimize satellite navigation as a practicable technology and contributed to the momentum behind subsequent programs. Its legacy is visible in the proliferation of global navigation satellite systems (GNSS) used today for mapping, transportation, emergency response, and many consumer applications. Historical accounts treat the 1964 demonstration as a key moment in a broader multi-decade transition from experimental observations to ubiquitous, precise, space-based positioning.