Sirius FM-1

Sirius FM-1, also known as Radiosat-1, was an American communications satellite operated by Sirius XM Radio, formerly known as Sirius Satellite Radio. The satellite was manufactured by Space Systems Loral (SS/L) and built on the proven LS-1300 satellite bus, widely used for high-power communications spacecraft.

The satellite was successfully launched on June 30, 2000, at 22:08 UTC, aboard a Proton-K/DM-3 launch vehicle. The launch was arranged by International Launch Services (ILS) and took place from Launch Site 81/24 at the Baikonur Cosmodrome in Kazakhstan.

Sirius FM-1 was placed into a highly elliptical Tundra orbit, allowing it to provide continuous satellite radio broadcast services across North America. From this orbit, the spacecraft supported Sirius’s nationwide digital audio broadcasting network.

The satellite was designed for an expected operational lifespan of approximately 15 years. After more than a decade of successful service, Sirius FM-1 was officially decommissioned in 2016 and maneuvered into a disposal orbit, marking the end of its operational mission.