For years, GPS receivers across Europe have experienced brief, repeated signal blackouts lasting three to five seconds, all occurring at the exact same time. These outages were too widespread to originate from ground-based transmitters, leading GPS expert Todd Humphreys and his student Zach Clements to investigate space-based sources. By analyzing signal arrival times at monitoring stations in Amsterdam and Trondheim, they pinpointed the source: Cosmos 2546, a Russian satellite in a missile-warning constellation.

The interference occurs in clusters during weekday business hours, suggesting human-directed testing rather than automated malfunction. While no official explanation has been given, Humphreys believes the activity represents periodic testing of a disruptive capability that could be highly damaging in conflict. Unlike accidental interference, this signal jamming is precise and intentional.

The discovery raises concerns about the militarization of space and the vulnerability of civilian GPS infrastructure. As satellite-based navigation underpins transportation, emergency services, and financial systems, deliberate jamming poses a strategic threat. The findings highlight how modern conflicts may increasingly unfold beyond Earth’s atmosphere, with implications for global security and communication resilience.