An Atlas 5 rocket carrying the U.S. Navy’s MUOS 4 satellite. Photo: ULA

[Via Satellite 09-02-2015] United Launch Alliance (ULA) launched the U.S. Navy’s fourth Mobile User Objective System (MUOS 4) satellite on Sept. 2 aboard an Atlas 5 rocket. The fourth satellite globalizes the MUOS footprint, bringing both legacy Ultra-High Frequency (UHF) and new Wideband Code Division Multiple Access (WCDMA) communications capabilities. The narrowband tactical satellite communications system provides new Beyond-Line-of-Sight (BLOS) communications capabilities, with smart phone-like simultaneous voice, video and data.

ULA launched the MUOS 4 satellite aboard an Atlas 5 Evolved Expendable Launch Vehicle (EELV) 551 configuration vehicle, which includes a 5-meter diameter payload fairing along with five Aerojet Rocketdyne solid rocket motors attached to the Atlas booster. The rocket used the Russian-built RD-180 engine from RD Amross for the first stage, and the Aerojet Rocketdyne RL10C-1 engine for the Centaur upper stage. This is ULA’s eighth launch of 2015.