The US military is set to launch on Monday its fourth communications satellite that supports mobile US forces on the ground, the Navy's space and warfare command announced in a press release.

The communications satellite, called the Mobile User Objective System (MUOS), operates like a smartphone network in space to support mobile US forces on the ground by transmitting on-demand voice and mission data on a high-speed IP-based system, the Navy explained on Friday.

The satellite is launched using an Atlas V rocket powered by a Russian-built RD-180 engine, which has come under fire recently because the US Congress wants to phase out the engines to penalize Moscow for alleged interference in Ukraine.

Congressional legislation passed last year requires the United States to develop a domestically produced rocket propulsion system by 2019. However, it will take five to seven years to build such an alternative, resulting in a possible two to five year space assurance gap, according to the US Air Force.

MUOS-4, according to the release, will benefit all of the US military services, including allowing the US Army to extend satellite communication to individual soldiers and enhance the Navy's submarine communication capabilities.

The MUOS-1 and 2 satellites, launched in 2012 and 2013, provide legacy support from their orbits over the Pacific Ocean and the United States, the release explained, while MUOS-3 awaits final testing.

The MUOS "constellation" will extend communications availability well past 2025.

Monday's launch window is between 6:07 and 6:51 am Eastern Standard Time (EST), but the Navy is keeping a close eye on Tropical Storm Erika to ensure it will not impact the launch.