US Navy's MUOS-4 moves toward 2015 launch date

The US Navy’s newest Mobile User Objective System (MUOS) satellite is progressing toward its 2015 launch date, with Lockheed Martin completing thermal vacuum testing on the satellite.

MUOS-4 underwent thermal vacuum testing inside the Dual Entry Large Thermal Altitude chamber at Lockheed Martin’s Sunnyvale, California satellite integration facility during November. The system will now proceed to final integrated testing ahead of its launch - expected in the second half of 2015 – when it will complete the operational MUOS constellation and provide global coverage.

MUOS operates like a smart-phone cell tower in the sky, providing significantly improved secure mobile satellite communications for warfighters on the move. For the first time, MUOS Wideband Code Division Multiple Access technology users will have beyond-line-of-sight capability to transmit and receive voice and data using an Internet Protocol-based system.

Iris Bombelyn, vice president, narrowband communications mission area, Lockheed Martin, said: ‘The successful completion of thermal vacuum testing assures that MUOS-4 can endure the extreme hot and cold temperatures it will experience throughout its on-orbit mission life. The delivery of this fixed price vehicle shows a clear advantage for block buys to drive down defects and maintain low costs through learning curve advantages.’

MUOS-3 was shipped to Cape Canaveral Air Force Station in early November in anticipation of its January launch.

Lockheed Martin is currently under contract for five MUOS spacecraft. MUOS-2 was launched and handed over to the US Navy for operations in 2013; while MUOS-1 launched and became operational in 2012. MUOS-5 is expected to launch in 2016.

Lockheed Martin Space Systems, Sunnyvale, California, is the MUOS prime contractor and system integrator. The US Navy's Program Executive Office for Space Systems and its Communications Satellite Program Office, San Diego, California, are responsible for the MUOS programme.