Pulsar

Quick facts

Overview

Summary

Mission Capabilities

The primary instrument onboard the Pulsar satellites is a high-power signal transmitter utilising a proprietary digital navigation waveform generator. This instrument broadcasts navigation signals in L-band and C-band, ensuring resilience to interference and jamming, thereby enhancing the reliability of PNT services. The system aims to achieve global centimetre-level positioning accuracy, a significant improvement over traditional Global Navigation Satellite Systems (GNSS) capabilities.

Performance Specifications

The Pulsar satellites operate in a sun-synchronous low Earth orbit (LEO) with an altitude of approximately 525 km and an inclination of around 97°. The L-band and C-band broadcasts give the Pulsar waveform generator a spectral range from 1530 nm - 1625 nm.

Space and Hardware Components

The Pulsar satellites are built on the Versatile Satellite Platform (VSP) manufactured by Aerospacelab. These smallsats are designed for rapid production and deployment, featuring a modular design. Each satellite includes a distributed clock architecture, consisting of a network of synchronised oscillators, compact rubidium clocks, and time transfer systems for continuous synchronisation.

Overview

The Pulsar satellite system, developed by Xona Space Systems, is a planned commercial satellite constellation designed to provide high-precision positioning, navigation, and timing (PNT) services. The technology demonstration mission, Huginn, launched on May 25, 2022. The full constellation is planned to house between 250 and 300 satellites. Pulsar plans to meet the growing demands of modern autonomous and intelligent technologies which require more accuracy and reliability than is offered by traditional GPS systems. Xona aims to enable technologies like autonomous vehicles or agricultural robotics systems to operate safely and efficiently in unstructured environments by leveraging the scalability of space-based solutions, providing real time and extreme high accuracy geolocation data. 4) 5) 7) 9)

PNT services work by using signals from a constellation of satellites to provide accurate location, movement, and time data to users. These services offer numerous benefits, including enhanced precision for location-based services, improved synchronisation for telecommunications and power grids, and robust support for autonomous vehicles and drones. By leveraging advanced technologies such as distributed clock architectures and high-power signal transmitters, systems like Xona Space Systems’ Pulsar aim to deliver centimetre-level accuracy and resilience against interference, significantly improving upon traditional Global Navigation Satellite Systems (GNSS). This is enabled by the low Earth orbit (LEO) in which they operate, allowing greater received signal strength on the Earth’s surface, improving positioning accuracy and minimising interference. 5) 6) 9) 11)

Spacecraft

The Pulsar satellites are built on the Versatile Satellite Platform (VSP) manufactured by Aerospacelab. These smallsats are designed for rapid production and deployment, using a modular design. Each satellite will feature a distributed clock architecture, to replace bulky traditional atomic clocks. These systems consist of a network of synchronised oscillators, which provide stable frequency references, compact rubidium clocks and time transfer systems which continuously synchronise the timing. 1) 2)

Launch

The first Pulsar satellite, Huginn, a technology demonstration mission, was successfully launched on May 25, 2022, aboard the SpaceX Transporter-5 mission. The launch used a Falcon-9 rocket and occurred at 14:35 EDT from Cape Canaveral. Huginn operates in a sun-synchronous low Earth orbit (LEO), with an altitude of approximately 525 km and an inclination of about 97°.

Xona Space Systems is planning a multi-phase rollout for the Pulsar constellation, with Phase 1 consisting of about 40 satellites, providing an in view GNSS enhancement service over mid-latitude population centres. This will offer GNSS correction services and rapid Precise Point Positioning (PPP) convergence to centimetre-level positioning with a secure and resilient additional ranging signal. Phase 2 will expand the constellation to about 70 Pulsar satellites, offering the same services as Phase 1 at a global scale, while Phase 3 will expand the constellation to the envisioned 250-300 satellite scale.  4) 10)

Mission Status

• May 8, 2024: Xona raised $19 million in Series A funding to accelerate the deployment of its LEO satellite network, aiming to commence beta operations of the Pulsar service . 3)
• May 25, 2023: Xona successfully transmitted precision LEO PNT signals from its demonstration satellite, Huginn. The company validated its ability to provide centimetre-level user positioning and demonstrated on-orbit reprogrammability of its digital navigation waveform generator. 12)
• May 22, 2023: Huginn, the Pulsar technology demonstration mission was successfully launched aboard the SpaceX Transporter-5 mission. 4) 10)
• April 4, 2023: Xona announced a partnership with Orolia (Safran) to develop support for its LEO constellation and navigation signals in Skydel-powered simulation and testing products. 8)

Sensor Complement

The primary instrument onboard the Pulsar satellites is a high-power signal transmitter that utilises a proprietary digital navigation waveform generator. The instrument will broadcast navigation signals in L-band and C-band, with a spectral range between 1530 nm - 1625 nm. Additionally, due to the low orbit altitude of the Pulsar satellites, these transmitted L- and C-band signals will be more resistant to jamming and interference than traditional GNSS systems, as the reduced distance from receivers results in up to 100 times more user-end power. With this instrument, Xona aims to achieve global centimetre-level positioning accuracy. This has been validated at a small scale, following the successful launch and broadcasts of the Huginn technology demonstration mission. 5) 6) 7) 9) 12)

Ground Segment

The Pulsar constellation will be operated by Xona Space Systems, using commercially owned ground stations. These stations will require larger scale atomic clocks than those carried by Pulsar satellites, for calibration and synchronisation of the constellation through onboard time transfer systems. Additionally, the Pulsar satellites are designed for in-orbit reprogrammability of the proprietary navigation waveform generator, to guarantee security and real-time bug fixes. These programming adjustments will be made through commercial ground stations. 6) 7)

References  

1. Aerospacelab: Home, URL: https://www.aerospacelab.com/

2. Erwin, Sandra. “Aerospacelab to build Xona Space's first navigation satellite.” SpaceNews, 19 March 2024, URL: https://spacenews.com/aerospacelab-to-build-xona-spaces-first-navigation-satellite/

3. Erwin, Sandra. “Xona raises $19 million Series A funds for satellite navigation service.” SpaceNews, 8 May 2024, URL: https://spacenews.com/xona-raises-19-million-series-a-funds-for-satellite-navigation-service/

4. “Falcon 9 Block 5 | Transporter 5.” Next Spaceflight, URL: https://nextspaceflight.com/launches/details/6804

5. Korogodin, Ilya. “Xona Pulsar: Obvious and Not-so-Obvious Issues of Next-Gen GPS.” Medium, 29 May 2022, URL: https://medium.com/@ilyakorogodin/xona-pulsar-obvious-and-not-so-obvious-issues-of-next-gen-gps-80ba053dc96c

6. Luccio, Matteo. “PNT by Other Means: Xona Space Systems.” GPS World, 5 July 2023, URL: https://www.gpsworld.com/pnt-by-other-means-xona-space-systems/

7. Reid, Tyler. “Launching Xona's Ravens: Commercial Satnav from LEO.” Inside GNSS, 18 May 2022, URL:  https://insidegnss.com/launching-xonas-ravens-commercial-satnav-from-leo/

8. “Safran to Provide GNSS Simulation Solutions for Xona Space System's Low-Earth-Orbit Constellation and Navigation Signals.” Xona Space Systems, URL: https://www.xonaspace.com/safrantoprovidegnsssimulationsolutionsforxonaspace

9. Schrock, Gavin. “Low Earth Orbit Satellites for Resilient Positioning, Navigation, and Timing.” GoGeomatics, 12 January 2022, URL: https://gogeomatics.ca/leo-pnt-xona/

10. Sorensen, Jodi. “Spaceflight launches five customer payloads aboard SpaceX's Transporter-5 mission and debuts the firm's latest OTV — Sherpa-AC – SatNews.” SatNews, 30 May 2022, URL: https://news.satnews.com/2022/05/30/spaceflight-launches-five-customer-payloads-aboard-spacexs-transporter-5-mission-and-debuts-the-firms-latest-otv-sherpa-ac/

11. “Xona and Lockheed Martin Collab.” Xona Space Systems, URL: https://www.xonaspace.com/xonalockheedmartinstrengthenpulsar

12. “Xona Broadcasts Demo PNT Signals.” Xona Space Systems, URL: https://www.xonaspace.com/xonademospntsignals