A United Launch Alliance (ULA) Atlas 5 rocket carrying the third Mobile User Objective System satellite. Photo: ULA

[Via Satellite 01-21-2015] United Launch Alliance (ULA) successfully launched the third Mobile User Objective System (MUOS 3) satellite for the U.S. Navy on Jan. 20 aboard an Atlas 5 rocket. The next-gen narrowband tactical communications satellite weighed nearly 7.5 tons.

MUOS 3 was the first mission of 2015 for the Boeing–Lockheed Martin joint venture, and used an Atlas 5 Evolved Expendable Launch Vehicle (EELV) 551 configuration vehicle. An RD-180 engine from RD Amross and a Centaur upper stage using Aerojet Rocketdyne’s RL10C-1 engine powered the rocket. The mission was the 52nd for the Atlas 5, the fifth Atlas 5 551, and marked the 200th Atlas-Centaur launch.

Built by Lockheed Martin, MUOS will succeed the legacy Ultra-High-Frequency (UHF) satellite system, providing 16 times the capacity of its predecessor. The fourth MUOS satellite is slated to launch later this year, and the fourth and final MUOS ground station is on track for completion in the coming months.