Science

MARAFON-D GVM

Russian Mass Simulator (Marafon Constellation Precursor — Not a Functional Satellite) · Roscosmos / ISS Reshetnev

This isn't actually a satellite. Marafon-D-GVM is a dead weight — a precisely shaped, precisely weighted chunk of metal with no instruments, no power system, and no mission of its own, launched purely to fill a slot on the rocket where a real satellite was supposed to be. That real satellite, Marafon-D, was meant to test hardware for Russia's planned Marafon constellation — a low-orbit satellite network intended to provide aircraft and mobile internet connectivity, one piece of Roscosmos's sprawling Sfera mega-project combining over 160 planned communications, broadband, and Earth-observation satellites. Marafon-D got pulled from the launch manifest shortly before liftoff in February 2024, and rather than fly the rocket with an empty slot, engineers swapped in this inert mass simulator — 'GVM' is short for the Russian term for a dimensional-mass mockup — just to keep the vehicle's balance and separation mechanics unchanged. It's still up there today, a stand-in for a satellite that never showed up, orbiting on behalf of a constellation Roscosmos is building for real elsewhere: 132 operational Marafon satellites are under contract with manufacturer ISS Reshetnev, with plans to expand to 271 by 2030.