Level 1 - Absolute Beginner

GPS tells you where you are. Your phone uses it. Cars and planes use it too.

A small company called Xona wants to make something better. It is in California, in the United States.

Xona will send six satellites into space this month. A SpaceX rocket will carry them. The new system is called Pulsar.

GPS can tell your place within a few metres. Xona says Pulsar can do it within a few centimetres. That is much more exact.

GPS

A system of satellites that tells you where you are on Earth.

satellite

A machine that goes around the Earth in space.

rocket

A vehicle that flies up into space.

company

A business that makes or sells things.

system

A set of parts that work together.

metre

A unit of length, about the height of a door handle.

centimetre

A small unit of length. One hundred centimetres make one metre.

exact

Correct in every detail, with no mistakes.

Level 2 - Elementary

Xona Space Systems, based in Burlingame, California, plans to launch six satellites on a SpaceX rocket later in October. Four of them are similar to a prototype the company put in orbit in 2025 and use a platform built by Aerospace Labs. The other two were made entirely by Xona and form the first pieces of a planned network of 258 satellites called Pulsar.

Ordinary GPS can place you within a few metres. Xona says Pulsar will be accurate to within a few centimetres, and that its signal is strong enough to be picked up inside buildings and between tall city blocks. Once the satellites are in orbit they will pass over the middle latitudes about eight times a day, which is enough to begin testing with real customers.

Accuracy is not the only problem the company is trying to solve. GPS signals are weak and easy to block or fake, a trick known as jamming or spoofing. Chief Executive Brian Manning believes the Pulsar signal is strong enough to put jammers off. He has also pointed out that GPS is free, so for a company the service itself is not the market.

Xona was started in 2019 by five engineers who met during a graduate programme in aerospace at Stanford University. It has raised just over three hundred million dollars, including twenty million from the United States Space Force. One early partner is TimeBeat, a timing company whose chief executive, Ian Gough, plans to use the trial to check and correct the clocks in its devices around the world.

prototype

An early model of something built to test the idea.

orbit

The curved path an object follows around a planet.

network

A group of connected things working as one system.

accurate

Exactly correct.

signal

A radio wave or message sent from one place to another.

jamming

Deliberately blocking a radio signal so it cannot be used.

spoofing

Sending a fake signal so a device is tricked about its position.

graduate programme

A university course taken after a first degree.

Level 3 - Intermediate

Later this month a SpaceX rocket will carry six satellites built by Xona Space Systems into low Earth orbit, and with them the first working elements of an attempt to build a commercial rival to GPS. Four of the six resemble a prototype the Burlingame company flew in 2025 and ride on a platform supplied by Aerospace Labs. The remaining two were constructed in house and are intended as the foundation of Pulsar, a planned constellation of 258 satellites.

The pitch rests on two claims. The first is precision: where GPS resolves a position to within metres, Xona says Pulsar will do so to within centimetres, which is the difference between knowing roughly which lane a car is in and knowing exactly. The second is robustness. GPS signals arrive faint after a journey from medium Earth orbit, which makes them easy to jam or to spoof with a counterfeit transmission. Chief Executive Brian Manning argues that a signal broadcast from much closer in will be strong enough to discourage interference and to penetrate buildings and dense urban canyons.

The engineering choice that makes this affordable is the deliberate omission of atomic clocks. Satellite navigation depends on extraordinarily precise timekeeping, and traditional systems carry expensive clocks on board. Xona's satellites instead exploit their low orbit and frequent contact with ground based time references, a design that keeps the hardware cheap. Just as importantly, existing GPS receivers can be adapted to the new signals with a software update rather than new silicon, which eases both commercial adoption and the regulatory path to broadcasting navigation signals at all.

The company was founded in 2019 by five engineers who met in Stanford's aerospace graduate programme, among them Chief Technology Officer Tyler Reid, whose doctoral work on using low Earth orbit satellites for navigation became the founding idea and who had previously worked on self driving cars at Ford. Xona has raised a little over three hundred million dollars, including twenty million from the United States Space Force, and will begin beta testing once the satellites are passing over the middle latitudes roughly eight times a day. TimeBeat, led by Ian Gough, will use the pilot to verify timing in its equipment worldwide. Full coverage of the United States, Europe, Japan and South Korea is the target for 2028.

constellation

A group of satellites working together as one system.

precision

The degree of exactness of a measurement.

robustness

The ability to keep working under difficult conditions.

counterfeit

Made in imitation of something real in order to deceive.

urban canyon

A street enclosed by tall buildings on both sides, where signals bounce or fade.

atomic clock

An extremely accurate clock that keeps time using the vibration of atoms.

Level 4 - Advanced

Satellite navigation is the rare piece of infrastructure the world uses constantly and pays nothing for, which is precisely why nobody has been in a hurry to improve it. Xona Space Systems is betting that the calculation has changed. Later this month six of its satellites will ride a SpaceX rocket into low Earth orbit: four derived from a prototype the Burlingame company flew in 2025 on an Aerospace Labs bus, and two built entirely in house that constitute the first operational nodes of Pulsar, an intended constellation of 258 spacecraft.

The commercial thesis turns on the two deficiencies of the incumbent systems. GPS, and the European, Chinese and Russian analogues built alongside it, resolve position to the metre, which is adequate for a driver reading a map and inadequate for an agricultural robot thinning a row of lettuces or a vehicle deciding whether it occupies a lane. They are also structurally fragile: signals that have travelled from medium Earth orbit arrive faint enough to be overwhelmed by a modest jammer or displaced by a counterfeit transmission, a vulnerability that has moved in a few years from theoretical to routine. Chief Executive Brian Manning's contention is that broadcasting from far lower altitude yields a signal robust enough to deter interference and to survive inside buildings and in the urban canyons where conventional reception collapses.

What makes the economics tractable is an elegant piece of engineering austerity. Precise navigation is fundamentally a timing problem, and legacy constellations solve it by flying costly atomic clocks. Xona's spacecraft dispense with them, relying instead on their low orbit and consequently tight coupling to ground based time references to hold the necessary accuracy. The second design decision may matter even more commercially: because installed GPS receivers can be taught the new signals through a software update rather than replacement hardware, Xona sidesteps the chicken and egg problem that has killed previous challengers, and simplifies the regulatory case for broadcasting navigation signals in the first place.

The company's provenance is academic. Five engineers who met in Stanford's aerospace graduate programme founded it in 2019, among them Chief Technology Officer Tyler Reid, formerly of Ford's self driving car effort, whose thesis on navigation from low Earth orbit supplied the founding premise. Funding stands a little above three hundred million dollars, including a twenty million dollar contribution from the United States Space Force, a sum whose significance lies less in its size than in what it signals about official appetite for an alternative to a system the military itself depends on. Beta service begins once the satellites are overflying the mid latitudes some eight times daily, with TimeBeat, under Chief Executive Ian Gough, among the first users, verifying and correcting timing across its global fleet of devices. Xona aims to cover the United States, Europe, Japan and South Korea by 2028. Manning's own summary of the opportunity is characteristically dry: GPS is free, so the market is not the service.