It started with a slip of the mouse. Scott Tilley, an amateur satellite tracker based in British Columbia, Canada, was tinkering with his radio equipment in early October 2025 when he accidentally scanned a frequency band that’s usually silent. What he found, however, was anything but quiet. Instead of the expected radio silence, Tilley’s receiver picked up a persistent signal streaming down from space. As he dug deeper, he realized he had stumbled upon a mystery with far-reaching implications for the future of space communications—and for SpaceX, the private company at the heart of the story.
According to NPR, Tilley’s discovery centered on a classified network of SpaceX satellites known as Starshield, a government-contracted constellation built for national security purposes. The signal he detected was coming from 170 Starshield satellites, all transmitting in the 2025-2110 MHz range—a band of the radio spectrum officially reserved for uplinking data from Earth to satellites in orbit, not the other way around. In other words, these satellites were sending data down to Earth on a frequency that’s supposed to be used only for sending commands up to space.
This seemingly technical detail has significant consequences. The International Telecommunication Union (ITU), a United Nations agency responsible for coordinating global use of the radio spectrum, strictly regulates which frequencies are used for which purposes. According to Tilley and corroborated by NPR, using uplink-only frequencies for downlink transmissions violates ITU standards and could potentially interfere with other satellites’ ability to receive vital commands from Earth. "Nearby satellites could receive radio-frequency interference and could perhaps not respond properly to commands—or ignore commands—from Earth," Tilley warned in his interview with NPR.
The potential for disruption is real, but the extent of any actual damage remains unclear. Kevin Gifford, a computer science professor at the University of Colorado Boulder who specializes in radio interference from spacecraft, told NPR, "I think it is definitely happening," referring to the possibility of interference. However, Gifford also noted that so far, there’s no concrete evidence that other satellites have suffered major disruptions, suggesting that the impact may be limited—at least for now.
The discovery was, by all accounts, serendipitous. Tilley described the moment to NPR: "It was just a clumsy move at the keyboard. I was resetting some stuff and then all of a sudden I’m looking at the wrong antenna, the wrong band." When he noticed the unexpected signal, he quickly hit record and began analyzing the data. By comparing his findings with a global catalog maintained by fellow amateur satellite trackers, he soon identified the culprit: Starshield.
Starshield is not your average satellite network. First revealed by SpaceX in 2022, it leverages the broadband technology behind the company’s public Starlink satellites but adds "additional high-assurance cryptographic capability to host classified payloads and process data securely, meeting the most demanding government requirements," according to SpaceX’s own description. The U.S. government—specifically agencies like the National Reconnaissance Office (NRO), Department of Defense, and U.S. Space Force—contracts SpaceX to operate Starshield for missions involving classified data and national security.
Since May 2024, the NRO has conducted 11 launches of Starshield satellites, building what it calls a "proliferated system" of over 200 satellites designed to provide rapid, resilient communications and Earth observation capabilities. "The NRO’s proliferated system will increase timeliness of access, diversify communications pathways, and enhance resilience," the agency said in a statement quoted by NPR. "With hundreds of small satellites on orbit, data will be delivered in minutes or even seconds."
But why would SpaceX risk regulatory trouble by transmitting on unauthorized frequencies? Tilley speculates that using uplink-only bands for downlink transmissions could be a deliberate attempt to conceal Starshield’s activities. "The decision to downlink in a band typically reserved for uplinking data could also be designed to hide Starshields’ operations," he told NPR. The signals’ precise frequencies shift regularly, which might make them harder for outsiders to track or identify.
Gifford offered another possible explanation: SpaceX may simply be taking advantage of a quiet part of the spectrum. Uplink transmissions from Earth to satellites are usually rare and brief, so those frequencies tend to be unused most of the time. "SpaceX is smart and savvy," Gifford said. He suggested the company might have decided to "do it and ask forgiveness later." After all, the ITU doesn’t impose fines for such violations, so the risk of tangible consequences is low. As reported by NPR and other outlets, SpaceX has a reputation for pushing regulatory boundaries in its quest to lead the space industry.
So far, there have been no public complaints from other satellite operators about interference, and it’s possible the Starshield signals haven’t caused significant problems yet. Still, the potential for disruption remains, especially as the number of satellites in orbit continues to grow. Tilley decided to go public with his findings out of concern for the broader community of satellite operators. "These are objects in classified orbits, which could potentially disturb other legitimate uses of space," he said.
The Starshield case also highlights the increasing complexity—and opacity—of space operations. Unlike the public-facing Starlink network, which uses much higher frequencies to deliver broadband internet around the world, Starshield operates at lower frequencies, likely supporting data rates closer to those of 3G cellular networks. This lower-speed, higher-security approach is well-suited for the military and intelligence missions the constellation is designed to serve, but it also makes the system harder for outsiders to monitor.
The U.S. government, for its part, has invested heavily in the Starshield program. According to NPR, the network has received more than $1.8 billion in funding so far, underscoring its importance to national security strategy. The NRO’s focus on a "proliferated architecture"—deploying hundreds of small, resilient satellites instead of a handful of large, vulnerable ones—reflects a broader shift in military thinking about space as a contested domain.
Neither SpaceX nor the NRO responded to NPR’s requests for comment about the frequency issue. This silence, combined with the classified nature of Starshield’s missions, leaves many questions unanswered about how the network is being used and how its operators intend to address concerns about radio interference.
For now, the episode serves as a reminder of the rapidly evolving challenges of managing the crowded and contested environment of Earth’s orbit. As more private companies and governments launch satellites for everything from communications to surveillance, the risks of accidental—or intentional—interference will only increase. Whether regulators, operators, and watchdogs can keep up remains to be seen.
One thing is certain: sometimes, the biggest discoveries come from the smallest accidents. And as Scott Tilley’s experience shows, even a clumsy click can reveal secrets orbiting high above us all.
