For decades, GPS and other global navigation satellite systems have relied on satellites orbiting about 20,000 kilometers above Earth. While these systems transformed navigation, they struggle in dense urban areas, indoors, beneath heavy tree cover, and in regions affected by signal jamming or spoofing. This Ars Technica article explores a new generation of low Earth orbit (LEO) navigation satellites that could overcome many of these limitations by operating much closer to Earth and transmitting signals up to 100 times stronger than conventional GPS.
The article focuses on California-based Xona Space Systems, which plans to launch the first six production satellites in its Pulsar constellation in October 2026, with initial services expected in 2027. Over time, the company intends to deploy 258 satellites capable of delivering centimeter-level positioning accuracy and timing precision measured in nanoseconds. These stronger signals could improve navigation inside buildings, increase resistance to GPS interference, and support applications such as autonomous vehicles, financial networks, telecommunications, transportation systems, and critical infrastructure.
The concept is not entirely new. Before GPS, the U.S. Navy relied on the Transit navigation system, a low Earth orbit satellite network introduced in the 1960s. Transit demonstrated that satellites in lower orbits could determine positions using Doppler shift measurements, but its limited constellation meant users often waited an hour or more between location updates. Advances in satellite manufacturing and the dramatic reduction in launch costs have revived the idea, making large LEO constellations economically feasible.
The article also explains that operating a navigation system in low Earth orbit presents engineering challenges. Hundreds of satellites are needed to provide continuous global coverage, unlike traditional GPS, which requires far fewer satellites in medium Earth orbit. Xona is addressing this challenge by designing satellites that are compatible with existing GPS hardware through software and firmware updates, reducing the need for new receivers. Partnerships with companies such as Trimble, Septentrio, STMicroelectronics, Safran, StarNav, and Keysight aim to accelerate adoption.
If successful, LEO navigation systems could complement rather than replace GPS, offering stronger, more secure, and more precise positioning services for industries where reliability is becoming increasingly critical.
