Detailed Review of LEO-PNT Pulsar from Xona Space Systems

Testing of the ambitious LEO-PNT project's technologies recently began. Are the ambitions justified? Can Pulsar change the rules of the game?

There are three letters that determine the rhythm of the modern world: PNT — Positioning, Navigation, Timing. This concept seems narrowly technical, but in reality, it lies at the core of almost everything we do daily. We have already discussed its criticality in detail in the PNT — three letters without which the modern world stops article.

Most people perceive PNT only as “satellite navigation” in a phone or car. Some separate from this the network protocols for precise time — for example, NTP servers that synchronize clocks on the internet. In fact, these are all parts of one whole: PNT — is spatial positioning, navigation, and time. It’s just that in some cases “N“ and “P“ work, while in others “T“ is critically important.

Satellite systems like GPS, Galileo, BeiDou, or GLONASS provide global positioning and navigation, and also distribute reference time. But they are — not the only source. There are terrestrial infrastructures, atomic clocks in data centers, network synchronization protocols. All of them together form the broad PNT ecosystem.

And it is the satellite component, which we are used to calling GNSS, that has its weaknesses:

• satellites fly high, so the signal reaches Earth very weakly;

• in urban “canyons,” it is lost between buildings;

• in the mountains or under a roof, it may not be present at all;

• the “cold start” time is sometimes measured in minutes;

• the signal is easily jammed or spoofed.

Therefore, despite all their importance, GNSS are not ideal. The world increasingly needs new PNT layers that will complement the existing ones. One such project is Pulsar from Xona Space Systems — an attempt to create a full-fledged PNT suite on Low Earth Orbit: not only navigation, but also time and positioning.