Satellite, Communications, Sirius FM-4


Display Status:

This object is on display in the James S. McDonnell Space Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.

Satellite, Communications, Sirius FM-4

Collection Item Summary:

This satellite represents the first generation of space-based, commercial radio service developed by Sirius Radio, a U.S. company (now Sirius XM Radio). Designed in 1987 and initiating service in 2001, the Sirius satellite system consisted of three satellites that provided more than 150 digital music and audio channels to North America. Their inclined geosynchronous orbits were a distinctive design feature that enabled clear radio reception over the entire country.

This FM-4 spacecraft was built as a flight-ready backup for the system but never used. The round antenna on the side of the spacecraft transmits radio signals to the ground. The solar panels are stowed as if for launch. Fully opened in orbit, they would span more than 24 meters (78 feet).

Sirius XM Radio and Space System Loral donated the satellite to the Museum in 2012.

Collection Item Long Description:

Inventory Number


Credit Line

Gift of Sirius XM Radio Inc. and Space Systems/Loral, Inc.


Country of Origin

United States of America


Aluminum, copper, carbon fiber, mylar, plastic


Overall [main antenna in stowed position]: 508 x 228.6 x 292.1cm, 1320kg, 591.8cm (16 ft. 8 in. x 90 in. x 115 in., 2910lb., 19 ft. 5 in.) With main antenna unstowed, depth: 591.8cm (19 ft. 5 in.)

Data Source

National Air and Space Museum

Restrictions & Rights

Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum