The global importance of GPS to military operations and everyday civilian life is well documented, as is the significant vulnerability posed by this reliance. Not just in the articles and opinions on SpaceNews, but even in congressional testimony. Specifically, the advanced and widespread RF jamming around Ukraine has spotlighted the expected impact in future conflicts.
While there has been active work to find alternative Position, Navigation and Timing (altPNT) solutions for terrestrial operations, including the questionable investment in a few new GPS satellites (R-GPS), there is little interest in protecting our on-orbit assets. Yet denied or disrupted PNT can significantly affect operations for key programs like MilSatCom or Missile Warning.
The White House advisory group on GPS recently issued a stark warning to the United States government, highlighting a critical shortfall in addressing escalating risks of interference with Pentagon-owned satellites. They also noted the alarming lack of progress in developing altPNT systems.
Our European partners on the Navigation Innovation and Support Program Advisory Committee of the European Space Agency issued a similar warning of the global over-reliance on existing PNT systems in its white paper, PNT Vision 2035.
The Space Force must aggressively step up its efforts in this area. Assured PNT should be a requirement on all defense and IC spacecraft, in the same way resilience against other system anomalies is required.
There are several proven options from a variety of commercial companies of all sizes to provide PNT resilience solutions. This reduces technology and vendor risk and would create a competitive opportunity for primes to differentiate as well as keep costs low.
The case for altPNT solutions
Integrating altPNT solutions is imperative for securing national resilience. Complementary systems can provide redundancy, ensuring that if one system is compromised, other systems can maintain PNT capabilities. A few altPNT solutions that can increase resilience include:
- Celestial navigation: Using stars, the moon, the Sun and other Earth-orbiting spacecraft for navigation is an ancient practice modernized with advanced sensors and algorithms. Modern celestial navigation systems use cameras and star trackers to determine a vehicle’s position based on celestial bodies. This method is beneficial in space, where terrestrial signals are unavailable.
- Quantum assisted navigation: Leveraging the principles of quantum mechanics, quantum sensors can provide exact measurements of time and space. These sensors can detect minute changes in gravitational fields or other environmental factors, offering a new level of accuracy and resilience in navigation. Quantum-assisted navigation is an emerging field with the potential to revolutionize PNT systems.
- Proliferated low-Earth orbit (pLEO) constellations: pLEO satellite constellations deliver robust, low-latency PNT services that significantly enhance traditional GNSS systems. By offering greater signal diversity and expanded coverage, pLEO constellations boost resilience against interference or disruptions. The extensive redundancy from the large number of satellites ensures that if one satellite fails or is compromised, others seamlessly take over, maintaining uninterrupted service.
Investing in altPNT solutions presents significant economic and strategic benefits. By mandating the inclusion of altPNT solutions on all space-bound vehicles, the government can drive the development and deployment of these technologies, fostering innovation and collaboration across the space industry. This mandate would enhance military resilience and benefit the commercial sector by promoting a diverse PNT ecosystem. Diversifying PNT infrastructure will not only drive growth in the space industry, but also push commercial innovation beyond GPS-like systems and advance the development of capabilities not reliant on RF signals for ranging.
A Call to Action
The U.S. Space Force is taking action to protect against everything except GPS resiliency. For example, the USSF has acknowledged the urgent need to safeguard satellites from adversarial threats, such as anti-satellite weapons developed by China and Russia, which can disrupt global GPS capabilities. Given the escalating risks, ensuring that all systems are GPS-resilient is imperative.
The federal government needs to secure PNT infrastructure for the conflicts of tomorrow and mandate the inclusion of altPNT solutions on all spacecraft. The FY25 Senate markup of the NDAA includes $217.7 million in Research, Development, Test, and Evaluation funding for PNT resiliency, mods and improvements. Policymakers, defense acquisition professionals and industry leaders must advocate for the requirement of altPNT solutions and the use of this funding toward addressing GPS resiliency on all future spacecraft.
The threats to PNT systems are growing, and the consequences of inaction now could be severe. The Space Force no longer has the luxury of time and requires urgent action to address GPS resiliency. The future of national security depends on the actions taken today to safeguard our PNT infrastructure.
Kevin Hause is the Chief of Strategy at Rhea Space Activity, a startup specializing in secure communication and reliable navigation in challenging environments, which offers an optical navigation product. He has more than 25 years of experience in global business operations specializing in leveraging emerging technologies to develop new business models for consumer media and commerce.
