In a strategic leap forward for military communications, L3Harris has delivered a major upgrade to the security backbone of the Mobile User Objective System (MUOS)—the U.S. Department of War’s premier ultra-high frequency satellite network. With the recent NSA certification of its upgraded Modem Transmission Security Controller (MTC), L3Harris ensures the constellation’s five active satellites—and the two more planned—stay secure, connected and combat-ready.
MUOS supports secure, narrowband, beyond-line-of-sight communications for everything from warfighters on the ground to airborne and maritime platforms. At the core of this mission is resilience—ensuring voice, video and data communications cut through the clutter, even in contested environments. The upgraded MTC generates cryptographic bitstreams to drive anti-jam modems at MUOS ground stations, safeguarding command and control links to each satellite in orbit.
But this isn’t just a tech refresh. It’s a future-proofing move. The newly certified MTC replaces aging first-generation ground Transmission Security (TRANSEC) devices, solving obsolescence issues while setting the stage for the MUOS Service Life Extension (SLE) program. The SLE initiative will launch two additional satellites, extending the system’s operational life by 15 years.
Every MUOS satellite already flies with L3Harris-built TRANSEC/Communication Security (COMSEC) units, and the company’s continued leadership in secure, high-Technology Readiness Level (TRL) programmable crypto platforms ensures seamless integration and interoperability. The result? A hardened, modernized MUOS constellation that’s ready for whatever the next 15 years of mission demands may bring.
L3Harris isn’t just keeping MUOS secure—it’s making it tougher, smarter and battle-ready for the long haul.
