The first of a new generation of mobile communications satellites built for the U.S. Navy has entered into service, the Navy said in a Nov. 21 press release.

The first Mobile Objective User System (MUOS), built by Lockheed Martin Space Systems, was launched in February aboard a United Launch Alliance Atlas 5 rocket. The satellite is equipped with a UHF-band narrowband payload to provide links to ships at sea and to mobile ground forces operating in hard to reach areas such as beneath dense forest canopies.

Sunnyvale, Calif.-based Lockheed Martin Space Systems is building five MUOS satellites and associated ground systems under a contract initially valued at $2.1 billion and awarded in 2004. One of those spacecraft will serve as an on-orbit spare.

The MUOS constellation is expected to provide 10 times the capacity of the legacy UHF Follow On system. The program has encountered delays that have helped drive up its cost and its most advanced capabilities are not yet available.

The second MUOS satellite is tentatively slated for launch in July 2013. Full operational capability is expected in 2015.