The U.S. Navy began replacing and upgrading its ultra-high frequency (UHF) satellite communications network during the 1990s with a constellation of customized satellites built by Hughes Space and Communications Company. Known as the UFO (Ultra High Frequency Follow On) series, these HS-601 model satellites support the Navy's global communications network, serving ships at sea and a variety of other U.S. military fixed and mobile terminals.
Geostationary OrbitThe W satellites are designed to provide telecommunications services primarily over Europe (Eutelsat W2, W3 and W5) and communication services over Russia and Africa (W4). W2, W3 and W5 are designed to offer 24 transponders at saturation and W4 is designed to provide 31 transponders at saturation. The W satellites have a minimum operational lifetime of 12 years. The spacecraft are based on the Spacebus-3000B2 platform. Sirius 3 provides direct-to-home television services to the Scandinavian region. Hughes upgraded NSAB's satellite control center at Esrange, Kiruna, and provided training to the satellite controllers. Sirius 3 was successfully launched on an Ariane-44L H10-3 on October 5, 1998. The satellite was built at the Integrated Satellite Factory of in El Segundo, Calif.
Geostationary Orbit