Using the Joint Tactical Radio System (JTRS) Handheld, Manpack, Small Form Fit (HMS) two-channel networking radio (AN/PRC-155), General Dynamics C4 Systems recently completed the first demonstration of secure voice and data communications via the Mobile User Objective System (MUOS) satellite-communications waveform. The demonstration used an AN/PRC-155 manpack radio -- running the MUOS waveform software -- to transmit encrypted voice through a MUOS-satellite simulator to the MUOS ground station equipment that will soon be deployed in Sicily . MUOS is a military satellite communications system that will enable secure, mobile networked communications worldwide, in even the most-austere environments. Development of the MUOS waveform remains on track for completion in the third quarter of 2012. By year-end, the MUOS capability will be available on the AN/PRC-155 manpack radio, the first MUOS terminal that will be available to soldiers.