A Canadian space enthusiast has uncovered what appears to be a classified group of SpaceX satellites transmitting on frequencies typically reserved for a different purpose. The surprising discovery was made by Scott Tilley, an amateur satellite tracker known for his knack for spotting unusual signals in orbit.
According to a report by NPR, Tilley was conducting his usual satellite monitoring routine from his home setup in British Columbia when he mistakenly tuned into a frequency band that generally carries no traffic. While adjusting his equipment, he noticed a signal coming from space in the 2025–2110 MHz range — a portion of the spectrum normally used for ground-to-satellite communications, not the other way around.
Finding this unusual, he recorded the data for several minutes. When he later compared the captured signals to an open database maintained by the global satellite tracking community, one name stood out: Starshield, SpaceX’s classified satellite constellation.
Inside SpaceX’s Secret Starshield Network
Starshield is a defense-focused satellite program developed by SpaceX for the U.S. military and intelligence agencies. It is designed to provide secure communication channels and surveillance capabilities, separate from the company’s commercial Starlink network that delivers internet access worldwide.
Reports suggest that more than 200 Starshield satellites are currently in orbit, many operated under the supervision of the National Reconnaissance Office (NRO), the U.S. agency responsible for intelligence-gathering satellites. Based on Tilley’s findings, signals from around 170 of these satellites were detected transmitting in the same restricted frequency range.
The fact that so many satellites were broadcasting on a band meant for uplinks rather than downlinks raised eyebrows among satellite experts, as it potentially indicates a breach of international communication standards.
A Frequency Reserved for Ground Stations
The International Telecommunication Union (ITU), which regulates global radio frequency use, designates the 2025–2110 MHz spectrum for uplinks — signals sent from Earth to satellites. Using this band to transmit data from satellites back to Earth is highly unusual and may interfere with nearby satellites operating in the same frequency range.
Typically, this portion of the spectrum is quiet, with only brief signals transmitted from ground stations to orbiting spacecraft. Persistent downlink activity, such as that observed from the Starshield satellites, could potentially disrupt communications or cause other satellites to miss important instructions from their ground controllers.
While there’s currently no public evidence of interference, the use of this frequency for military satellite operations highlights how crowded and complex space communications have become.
SpaceX’s Regulatory Grey Area
SpaceX has not commented publicly on the findings, and neither has the U.S. military, which closely guards details about classified space missions. The company has a history of pushing regulatory boundaries in pursuit of innovation, often opting to proceed first and address compliance later.
Experts speculate that the use of this unconventional frequency could be the result of testing, technical optimization, or an intentional operational choice approved under classified agreements. Given the absence of any complaints from other operators, it’s possible that the transmissions are carefully managed to minimize interference.
Still, the case raises questions about transparency and accountability, especially when private companies operate assets with military applications in shared orbital space.
Citizen Science Brings Hidden Activity to Light
To ensure his discovery was verifiable, Tilley published his data and analysis on Zenodo.org, an open-access research platform. This allows scientists, satellite operators, and regulators to review his findings and assess any potential risks.
Tilley has a long history of notable discoveries in the satellite tracking community. In 2018, he made headlines for rediscovering NASA’s IMAGE spacecraft, which had been considered lost for over a decade. His latest observation adds another remarkable entry to his record — showing how independent researchers continue to play a critical role in monitoring Earth’s increasingly crowded orbit.
