Satellites, once launched, never return to Earth unless there’s some sort of catastrophe, but pay-radio operator had an unwanted satellite on its hands in the shape of its FM-4 satellite. It stayed on the ground as a spare craft in case of problems with the original trio launched into space to provide programming for the Sirius radio service. The satellite has now been handed over to the Smithsonian Museum. It is being exhibited at the Museum’s offshoot at Chantilly, Virginia.

Originally built by Space Systems/Loral the satellite was designed to operate in a highly-elliptical ‘tundra’ orbit in order to ensure that its signals were more or less directly overhead the continental USA for best reception in the nation’s ‘concrete canyons’ of high rise buildings. However, in practice, Sirius’ ground-based repeater transmissions more than adequately filled in those potential gaps.

Sirius acquired XM Satellite Radio, which uses conventional geostationary satellites thus rendering FM-4 obsolete. Indeed, Sirius-XM will over the next year retire its three original craft as the programming they carry is now duplicated on the XM satellites. Sadly, those three original satellites, launched in a series starting in June 2000, once their mission is completed, be placed into a so-called graveyard orbit.

“The availability of a flight unit like Sirius FM-4, which was never launched, is extremely rare and will be a significant addition to the museum’s collection,” Martin Collins, space history curator at the Chantilly site. “Whether experienced in our cars or homes, the remarkable innovations offered by satellite services are often taken for granted — one indicator of how the space age has changed our lives.”

Categories: Articles, Digital Radio, DTH/Satellite