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COSMOS 2547 (705K)

Russian Navigation Satellite (GLONASS-K) · Roscosmos / ISS Reshetnev

Cosmos 2547 is a GLONASS-K satellite, the design that finally let Russia's navigation system speak the same digital language as everyone else's. Every earlier GLONASS satellite broadcast using FDMA — each satellite on its own slightly different frequency, a Soviet-era engineering choice that forced receiver manufacturers to build genuinely different hardware just to support GLONASS alongside GPS. GLONASS-K added CDMA signals, the same broadcasting method GPS, Galileo, and BeiDou all use, a deliberate step toward letting a single cheap receiver chip use all four systems interchangeably. It's also the first GLONASS generation built without a pressurized housing, cutting mass nearly in half versus the older GLONASS-M satellites it's gradually replacing.