US military nails GPS-free navigation in 4-hour ocean flight using quantum sensors

A successful flight test demonstrated that aircraft can navigate over the open ocean without relying on GPS, using quantum sensors to read subtle variations in Earth’s magnetic field. The test was conducted under the US Defense Innovation Unit’s MagNav program, which aims to develop resilient alternatives to satellite-based navigation for aviation and national security applications. The program focuses on technologies that can maintain accurate positioning when GPS signals are unavailable, disrupted, or deliberately jammed. In the particular case, an Embraer 170 flew for 4 hours and 23 minutes over the Pacific Ocean, traveling from Seattle’s Puget Sound to southern Alaska and back while operating without GPS. The system improved position accuracy by 89% compared with conventional backup navigation methods, while providing navigation data to pilots in real time through standard tablets. Turning Earth’s magnetic field into a navigation system MagNav, short for magnetic navigation, uses quantum sensors to detect variations in Earth’s natural magnetic field. These measurements create a magnetic map that aircraft can use to determine their position without depending on satellite signals. The development could provide a significant advantage in environments where GPS signals are unavailable, disrupted or deliberately jammed. Unlike satellite navigation, Earth’s magnetic field cannot simply be switched off or blocked by an adversary. “This is a significant win for the department’s quantum sensing priorities, showcasing that MagNav capabilities are no longer a distant research goal. We moved from problem sourcing to solicitation to prototype in a matter of months,” explained Kyle Norman, deputy director of DIU’s Kill Web portfolio. The technology also addresses limitations in conventional backup systems. Radar-based navigation and visual references such as roads, rivers and cities can be difficult to use over remote areas, while traditional onboard sensors can accumulate errors over time. By continuously comparing magnetic signatures against a map of Earth’s crust, MagNav is designed to provide an independent source of positioning information, including over featureless areas such as oceans. From prototype to military aircraft The MagNav program began in 2024 under the Transition of Quantum Sensing initiative. DIU received 72 applications before selecting Honeywell Aerospace to develop the prototype. The recent test represents an important move from laboratory development toward operational use. The system was able to stream navigation information directly to pilots using commercially available tablets, suggesting that adoption could require less modification to existing aircraft than more complex navigation systems. DIU and Honeywell now plan to conduct another demonstration aboard a US Air Force C-17 Globemaster III later this year. The larger military aircraft will provide an opportunity to test the technology in a more operationally relevant environment. If successful, MagNav could become an additional layer of navigation resilience for military aircraft operating in contested environments. Furthermore, it could also eventually provide a backup for civilian aviation, particularly as concerns grow over GPS interference and the vulnerability of satellite-based navigation systems.Get the latest in engineering, tech, space & science - delivered daily to your inbox.Bojan Stojkovski is a freelance journalist based in Skopje, North Macedonia, covering foreign policy and technology for more than a decade. His work has appeared in Foreign Policy, ZDNet, and Nature.