When we started Xona in 2019, the idea of building a commercial positioning, navigation and timing system in Low Earth Orbit was still pretty far outside the mainstream.
GPS had worked for decades. Navigation satellites were large, expensive government systems built to operate for decades at a time. The idea that a commercial company (and a startup at that) could rethink that architecture from an unproven orbit and ultimately deliver better performance at a fraction of the cost was not an obvious bet.
Flash forward, a lot has changed.
Today, LEO has become a proven architecture for delivering critical services from space, and new PNT efforts are emerging around the world to leverage this domain. At Xona, we’ve gone from early research, to our first demonstration mission, to Pulsar-0 proving the fundamental pieces of our system in orbit at record pace.
This October, six Pulsar satellites will launch aboard Bandwagon-5, marking the start of our production constellation and enabling the first private navigation service in LEO to begin serving customers for the very first time.
Six satellites, two jobs
Next month, we’re launching six Pulsar satellites. Four are built on the Pulsar-0 satellite bus architecture from Aerospacelab that has been modified to meet the needs of our navigation mission. Together, they’ll begin to provide service in our initial markets with a revisit time of ~12 hours. This service level enables us to begin to serve early customers while we ramp up deployment towards continuous global coverage.
The other two are the first satellites designed and manufactured in-house at Xona by our growing team in Burlingame, California. They’re purpose-built from the ground up to deliver the best navigation performance in the world and be manufactured at a cadence of multiple satellites per week, laying the foundation for scaling the Pulsar constellation.
Together, the six spacecraft mark a huge milestone for the evolution of the satellite navigation world as the first widely available dedicated commercial sat nav service will now be available, - the beginning of the transition to navigation services that evolve and grow at the pace of the commercial users we support.
Intentional orbits
For the last year, teams around the world have been testing and validating our signal design from the Pulsar-0 satellite we launched last June. With over 500 transmissions, we’ve demonstrated how much Pulsar outperforms GNSS in jammed and indoor environments, shown our ability to fend off spoofing attacks, demonstrated unprecedented <2cm accuracy, and have accomplished it all using commercial user equipment without any hardware changes.
With our upcoming launch, we’re moving into active service deployment and beginning to deploy the network multiple satellites at a time.. This creates an interesting engineering question – where should we put them first?
We could spread them farther apart and maximize the amount of time that at least one Pulsar satellite is visible, or stack them on top of each other, increasing the number of satellites in view and allowing us to demonstrate a stronger positioning solution some of the time. Or, you can find a way to do both.
Leveraging Earth’s natural precession, we’ve designed an orbital configuration that uses two orbital planes to create periods where four of our satellites can be visible together while simultaneously minimizing the downtime between one satellite in view, enabling us to demonstrate a complete positioning solution using just Pulsar signals while also serving our early demand.
Useful in the real-world
Four satellites are not a global navigation constellation, but that doesn’t mean Pulsar has to wait until the full constellation is deployed before it becomes useful.
Some of our earliest applications we’re working on are in critical timing infrastructure. Many of these systems already use technologies such as precision clocks that can continue operating when a GNSS signal is temporarily unavailable, creating an interesting role for Pulsar to add value even with intermittent coverage. From these four Pulsar satellites in orbit, early customers across the US, Canada, and most of Europe will receive 8 broadcasts a day, each lasting approximately 25 minutes each with a short window with four satellites in view during each pass.
A trusted Pulsar signal passing overhead, even intermittently, can provide another observation of time and location, an independent check that helps a system determine whether the GNSS information it is receiving makes sense and whether it can be trusted.
As we add satellites, those windows will become more frequent until Pulsar-derived timing becomes constant, and then redundant. As more Pulsar satellites come into view simultaneously, more applications become possible. Today's navigation receivers are hunting for the strongest, most resilient signal available. We’re building Pulsar to be the one they pick every single time.
Building the best navigation spacecraft in the world
While our four Pulsar satellites will bring service to customers sooner, our Test Satellites, PTS-1 and PTS-2, are solving a different problem.
We are optimizing for different things than a traditional GPS, communications, or observation spacecraft. We care deeply about signal power, precise timing, optimal signal clarity, rapid iteration, manufacturing scale, operational flexibility and the ability to keep improving what Pulsar can do after we start deploying it.
Owning the design gives us more control over our supply chain, but the bigger reason is engineering and cost control. As technology continues to advance, requirements will change. Threats will change. Receiver technology will change. We will learn things from operating the constellation that we cannot fully predict on the ground.
We need the ability to respond to those changes directly: to change hardware, software, payloads and manufacturing processes at the same pace which our customers do. And we need the ability to do this efficiently to keep the cost of our service accessible to everyone. Over the past few decades, GPS has been a stagnant service while the world around it innovates at an ever increasing pace. Pulsar is built to change that, which starts with building the best spacecraft for the job.
These two spacecraft are the first flight articles from a novel satellite design. Their purpose is to build flight heritage, build muscle in our mission operations, validate design choices on orbit, and show us where the next spacecraft should be better. We have already learned a massive amount from through the design and manufacturing of these first two spacecraft which will be rolled into the next iteration, and we expect to continue to learn more once they are on orbit.
Rising to the challenge
Pulsar-0 gave us confidence in our novel architecture for satellite navigation. We are now making the shift from technology development to service operations. We have to build, launch, and operate hundreds more satellites to fully activate Pulsar, deploy our client software with our customers across their user base, and grow the organization needed to support all the activities needed to become the world's new default source of “where” and “when.”
That shift is already happening inside Xona. We are building new teams and tackling the challenges to scale up Pulsar. With 60 open roles across engineering, manufacturing, product, and operations, we’re looking for the best people to help us meet the next challenge ahead. Join us.
