Satellite navigation is one of those technologies that became invisible precisely because it worked so well. GPS signals guide ships across oceans, synchronize financial transactions, and help smartphones pinpoint a location to within a few meters. Most people never think about it. That invisibility, though, conceals a growing vulnerability: GPS signals are increasingly being jammed, spoofed, and disrupted, and the system’s fundamental architecture makes it difficult to fix. A California-based company called Xona Space Systems is building what it believes is the answer, and the approach involves rethinking where navigation satellites should orbit in the first place.
Why Altitude Changes Everything
GPS and other global navigation satellite systems operate from medium-Earth orbit, roughly 20,000 kilometers above the surface. That distance is useful because a relatively small number of satellites can cover the entire planet. The tradeoff is signal strength: by the time a GPS signal travels that far and reaches a receiver on the ground, it is extraordinarily weak. That weakness is why GPS struggles inside buildings, under dense tree cover, and in urban canyons where tall structures block the sky.
Xona’s Pulsar satellites would operate in low-Earth orbit, much closer to the surface. According to the company, that proximity translates into signal strength roughly 100 times greater than what GPS delivers. Stronger signals are harder to jam. In live-sky jamming tests conducted across multiple countries using its first satellite, called Pulsar-0, Xona found that the increased signal power reduced a jammer’s effective area by 95 percent. The company has also built an anti-spoof watermark into Pulsar signals, allowing receivers to verify that the signal is authentic rather than a fabricated imitation. These are not incremental improvements. They represent a different category of resilience.
The first six production Pulsar satellites are scheduled to launch in October 2026, with early service beginning in 2027. Once the full constellation of 258 satellites is in orbit, Xona claims customers will be able to determine their location anywhere on Earth to within several centimeters. The company also expects its satellites to deliver timing accuracy to within 10 nanoseconds, which matters enormously for financial markets, telecommunications networks, data centers, and transportation systems. Several precision-timing customers have already signed on.
A Problem That History Already Solved Once, Differently
This is not the first time engineers have tried to navigate from low-Earth orbit. Before GPS existed, there was Transit, the world’s first satellite navigation system, developed in the 1960s for the US Navy. Its origins trace back to physicists at Johns Hopkins University’s Applied Physics Laboratory who were studying the Soviet Union’s Sputnik-1. By measuring the Doppler shift of Sputnik’s radio signals as the satellite passed overhead, they realized that the same principle could work in reverse: a receiver on the ground could calculate its own position by measuring the Doppler shift of a satellite with a known orbit.
Transit became operational in 1964, with 36 satellites designed primarily to help Polaris ballistic missile submarines fix their positions before launch. It worked, but it had a fundamental limitation. With only 36 satellites in a low orbit, a receiver might wait an hour or two between satellite passes. That was acceptable for a submarine that needed periodic position updates. It would be useless for real-time navigation.
The solution at the time was to move satellites higher. Medium-Earth orbit allowed GPS to cover the globe with far fewer satellites, providing near-instantaneous positioning. The cost was signal strength. Zak Kassas, director of the Autonomous Systems Perception, Intelligence, and Navigation Laboratory at The Ohio State University, has noted that a navigation constellation in low-Earth orbit requires roughly 10 times more satellites than an equivalent system in medium-Earth orbit. In the 1960s, building and launching that many satellites was not feasible. Today, it is.
What Makes This Moment Different
The economics of getting to orbit have changed substantially. Lower-cost rocket launches, driven in large part by SpaceX, have made large satellite constellations commercially viable. Starlink demonstrated that deploying thousands of satellites is operationally achievable. Xona is applying that same logic to navigation rather than broadband.
The company has contracted with Aerospacelab, a Belgian satellite manufacturer, to build some of its initial satellites. It is also developing an in-house satellite bus at its factory in Burlingame, California, aiming to manufacture most of the 258 Pulsar satellites internally. Pulsar-0 launched aboard a SpaceX Falcon 9 rideshare mission on July 1, 2025, and software updates have already improved its positioning accuracy from a 4.2-centimeter ranging error down to 1.5-centimeter accuracy.
Kassas has observed that the first customers for LEO navigation services will likely be organizations that already pay for premium positioning, navigation, and timing services: defense users, national security agencies, and government bodies responsible for infrastructure resilience. That is a realistic starting point. Precision agriculture, autonomous vehicles, and urban logistics could follow as the constellation grows and costs normalize.
Here is what most coverage of this story misses: the significance is not just that GPS has a competitor. It is that the vulnerability of a single, aging navigation architecture is becoming harder to ignore, and the technological barriers to building an alternative have quietly collapsed.
In Short
Xona Space Systems is building a constellation of 258 low-Earth orbit satellites designed to deliver navigation and timing signals roughly 100 times stronger than GPS. Stronger signals mean better performance indoors, under foliage, and in jamming environments. The physics behind the approach is not new: it echoes the Transit system of the 1960s. What is new is that launch costs have dropped enough to make a large LEO navigation constellation economically viable. The first production satellites are scheduled for late 2026. The broader implication is that satellite navigation, long treated as a solved problem, is entering a period of genuine architectural competition.
Based on reporting from Ars Technica.