Artist rendition of a MUOS satellite. Photo: Lockheed Martin

[Via Satellite 12-03-2015] The fourth Mobile User Objective System (MUOS) satellite finished on-orbit testing on Nov. 30, and has been accepted by the U.S. Navy. Launched Sept. 2, MUOS 4 is the latest addition to a network of orbiting satellites and relay ground stations designed to modernize secure communications for mobile military forces.

Once fully operational, the MUOS network will provide 16 times the capacity of the legacy ultra high frequency communications satellite system, which it will continue to support and eventually replace. More than 55,000 currently fielded radio terminals can be upgraded to be MUOS-compatible, with many of them requiring only a software upgrade. Lockheed Martin built the MUOS satellites, and opened a radio terminal facility for the constellation in December 2014.

MUOS 4 will be relocated in Spring 2016 to its on-orbit operational slot in preparation for operational acceptance. The satellite joins MUOS 1, MUOS 2 and MUOS 3, launched respectively in 2012, 2013 and January 2015, and four required MUOS ground stations. MUOS 5, an on-orbit spare, is scheduled for launch next year.

“MUOS 4 completes the initial constellation, providing the MUOS network with nearly global coverage. Mobile forces, equipped with MUOS terminals, will soon be able to communicate with each other — including voice, data and exchanging imagery — real-time, virtually anywhere on the Earth,” said Iris Bombelyn, Lockheed Martin’s vice president for narrowband communications.