Space navigation disruption escalates to low-earth orbit as Pentagon accelerates efforts to strengthen satellite network

Space navigation disruption escalates to low-earth orbit as Pentagon accelerates efforts to strengthen satellite network

In areas of conflict like Ukraine and the Middle East, GPS jamming, interference, and spoofing have become common, affecting aviation and maritime traffic. The effects on other satellites have been less reported but could be no less critical.

As GPS signals around Ukraine are being severely jammed, affecting satellites up to 1,200 miles above the Earth's surface, efforts to develop anti-jamming technology for GPS signals in low-Earth orbit (LEO) are gaining momentum.

Current efforts focus on both improving GPS satellite signals themselves and leveraging alternative satellite networks for resilient navigation.

The latest generation GPS satellites, called GPS III, broadcast a new kind of GPS signal called M-Code. This more powerful, encrypted signal is much more resistant to jamming and spoofing. Additionally, the GPS III Follow-On satellites will feature regional military protection (RMP) that focuses M-Code broadcasts on smaller areas, increasing signal strength by about 60 times to help counter jamming at higher altitudes, including in LEO.

On the commercial and maritime side, a pioneering project is using Iridium’s LEO satellite network to deliver anti-spoofing and anti-jamming navigation aids. This system provides resilient navigation and tracking solutions that immediately detect spoofing and maintain reliable navigation coverage in GPS/GNSS-compromised environments. Trials are underway for maritime applications, demonstrating the importance of alternative LEO constellations in offering navigation redundancy.

The U.S. Space Force is also advancing navigation technologies that do not rely on GPS or any satellite signals at all, such as a quantum inertial sensor demo aboard the X-37B spaceplane. This sensor aims to provide navigation in orbit without dependence on vulnerable satellite networks, enhancing navigational resilience against jamming and spoofing.

Regarding potential alternatives to GPS for space navigation, the integration of Iridium’s LEO constellation demonstrates a commercial pathway for global, resilient positioning beyond traditional GPS and GNSS constellations. Quantum inertial navigation sensors can autonomously detect position and velocity changes without external signals, representing a promising alternative for space missions vulnerable to GPS signal loss or deception.

Increasing reliance on multi-constellation GNSS (GPS, Galileo, GLONASS, BeiDou) combined with new anti-jamming signals like M-Code and alternative augmentation networks such as satellite relay and LEO constellations increases the robustness of positioning and timing.

If the interference becomes more prevalent, it could create regions in space where satellites in LEO cannot get GPS signals. The timing service offered by GPS is essential for businesses and the global economy, particularly for the financial system, power grid, internet, and computer networks.

Most satellites in low-Earth orbit use GPS, and the signal is relatively straightforward to interfere with due to its weakness relative to the noise floor. Spoofing GPS signals is feasible for both nation states and extremist organizations with the current state of technology.

Controlled reception pattern arrays (CRPAs) are available commercially and can remove jamming signals from the receiver's processing chain. However, CRPAs with a larger number of elements are restricted under arms export control regulations.

No single alternative to GPS is likely to be able to replace all of its services, similar to how no single alternative can replace the internet. But these efforts collectively address increasing threats of GPS jamming and spoofing in space and offer multiple layered alternatives to GPS for reliable space navigation.

[1] SpaceNews [2] Iridium [3] SGM Technology AS [4] NASA

1. The Space Force is exploring navigation technologies independent of GPS or satellite signals, such as quantum inertial sensors showcased on the X-37B spaceplane, enhancing navigational resilience against jamming and spoofing.
2. Iridium's LEO satellite network is being utilized to deliver anti-spoofing and anti-jamming navigation aids, offering resilient navigation and tracking solutions for GPS/GNSS-compromised environments.
3. The GPS III satellites, like the GPS III Follow-On, broadcast a more powerful encrypted signal, M-Code, and feature regional military protection (RMP) to increase signal strength and counter jamming at higher altitudes, including in LEO.
4. In low-Earth orbit (LEO), most satellites use GPS, making the signal easier to interfere with due to its weakness relative to the noise floor, and spoofing GPS signals is feasible with the current technology for both nation states and extremist organizations.
5. As GPS signals around Ukraine are severely jammed, the Pentagon is emphasizing the need for anti-jamming technology for GPS signals in LEO, and efforts are underway to improve these signals and leverage alternative satellite networks for resilient navigation.
6. Trials are ongoing for maritime applications of the Iridium LEO constellation's anti-spoofing and anti-jamming navigation aids, demonstrating the importance of alternative LEO constellations in offering navigation redundancy.
7. Increasing the use of multi-constellation GNSS (GPS, Galileo, GLONASS, BeiDou) in combination with new anti-jamming signals like M-Code and alternative augmentation networks such as satellite relay and LEO constellations increases the robustness of positioning and timing in space.
8. The environmental-science, space-and-astronomy, and general-news sectors follow closely the developments in aerospace, defense, and warfare concerning GPS and satellite navigation.
9. If the interference becomes widespread, it could create regions in space where satellites in LEO cannot receive GPS signals, potentially affecting critical services like the financial system, power grid, internet, and computer networks, causing financial and environmental impacts.

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