Lockheed Martin Space Systems of Sunnyvale, Calif., said June 14 that it had completed a series of ground tests on the first of the Mobile User Objective System (MUOS) satellites the company is building for the U.S. Navy.

MUOS is a next-generation narrowband tactical satellite communications system designed to provide the U.S. military with the latest mobile technology, including simultaneous voice, video and data as well as improved service to legacy users of the current Ultra High Frequency Follow-on system.

The first satellite in the planned five-satellite system recently completed approximately two months of testing in Sunnyvale designed to verify the overall performance of the integrated MUOS satellite and ensure, among other things, the electromagnetic compatibility of the satellite, its payloads and the launch vehicle.

U.S. Navy Adm. David Dorsett, director of naval intelligence, told the Senate Armed Services strategic forces subcommittee during a March hearing that the first MUOS satellite would launch in September 2011 and be ready to begin on-orbit operations in December 2011.

Lockheed Martin was awarded a $2.1 billion contract in September 2004 to build the first two MUOS satellites; options for three additional satellites boosted the total potential value to $3.26 billion. The program has encountered multiple delays