Russian Tundra satellites jam European GPS

The GPS signal guiding your phone is astonishingly faint. After travelling 20,000 km from orbit, it arrives weaker than the thermal noise of stars and sunlight. It works only because your receiver knows exactly what to listen for, filtering that whisper from the cosmic background. Now imagine someone in the next room starts shouting on a nearly identical frequency. The whisper vanishes.

That has been happening across Europe, from Iceland to Italy, at least 75 times since 2019. That "someone" is a constellation of Russian military satellites orbiting as high as 45,000 km above Earth.

Pinpointing a Satellite by Its Shadow

Researchers at the University of Texas, led by Prof. Todd Humphreys and student Zachary Clements, spent years tracking abrupt drops in GPS signal quality recorded by monitoring stations across Europe. Each time, the navigation signal collapsed by roughly a factor of ten, simultaneously across receivers spanning thousands of kilometres. Ground-based jammers, limited by Earth's curvature, cannot produce that pattern.

The culprit turned out to be Russia's Tundra satellites, part of the EKS/Kupol early-warning system designed to detect ballistic missile launches. These spacecraft fly in highly elliptical orbits, spending hours lingering near their highest point and staring down at the Arctic and Northern Europe. Their primary job is watching for rocket plumes. But their downlink transmissions home operate at 1,577.5 MHz, just 2.5 MHz from the GPS L1 frequency at 1,575 MHz. That proximity, combined with a powerful transmitter, bleeds energy into the GPS band like an amplifier bleeding into an adjacent radio station.

The team confirmed the source using a technique called time-difference-of-arrival. Think of it like triangulation in reverse: you measure the precise microsecond gap between an interference burst reaching two distant stations (Amsterdam and Trondheim, 1,500 km apart). That gap narrows the source to a shell-shaped surface in space. Combine enough station pairs and the shells intersect at a single point. Only one satellite sat at that point: Cosmos 2546, matching to within 200 metres. Spanish technology firm GMV independently corroborated the findings using comparable methods.

A Frequency That Spares Only GLONASS

The interference disrupts GPS (American), Galileo (European), and BeiDou (Chinese) signals, but leaves Russia's own GLONASS system untouched. The downlink frequency appears configured to avoid self-disruption while affecting every competitor. Whether this reflects deliberate design or fortunate engineering, researchers cannot yet say. A US Air Force briefing acknowledged the interference but did not publicly assess intent.

Each disruption lasts under ten seconds, synchronised with a satellite pass. Most devices recover by reverting to their last known position. Aircraft feel the sharpest operational impact: while commercial planes carry backup systems (inertial navigation, ground-based radio beacons), losing GPS increases pilot workload and degrades the precision of modern approach procedures that depend on satellite positioning.

Europe's Defence Has a Blind Spot

Europe's flagship countermeasure, Galileo's OSNMA authentication system, live since July 2025, lets receivers verify that a navigation message comes from a genuine satellite. It works well against spoofing, the fake signals broadcast from Kaliningrad's expanding network of 36 ground-based transmitters. But OSNMA does nothing against jamming. When brute-force noise drowns a signal, there is nothing to authenticate.

The deeper problem is detection. Until now, European security establishments have framed GPS interference as a ground-based threat. The space-based vector is a documented analytical blind spot. France is the sole European country with orbital detection capability: its NESS nanosatellite, launched in 2023, carries instruments designed to characterise interference sources from orbit. Germany plans to launch its own monitoring satellites in autumn 2026. Until then, Europe largely relies on American academics and ground-station data to identify threats arriving from 45,000 km overhead.

The longer-term fix, a European low-orbit navigation constellation called Céleste that would transmit stronger, harder-to-jam signals, will not be fully operational until the mid-2030s. In the meantime, Europe knows its navigation signals are being drowned out from space. It just cannot yet see who is holding the megaphone.