Inmarsat 5 mission. Photo: SpaceX.

SpaceX has successfully launched Inmarsat’s fourth and final high-speed broadband communications satellite, Inmarsat 5 F4, for its Global Xpress constellation. The satellite flew atop a Falcon 9 from Launchpad 39A at NASA’s Kennedy Space Center in Florida.

Following satellite separation at 7:53 p.m. EDT, Inmarsat acquired telemetry from its Perth ground station at 8:04 p.m. EDT. The launch team from Inmarsat and Boeing Network & Space Systems, the manufacturer of Inmarsat 5 F4, are now raising the spacecraft to a Geostationary Earth Orbit (GEO), at which point the satellite will deploy its solar arrays and reflectors and undergo payload testing.

Inmarsat 5 F4 joins the three GX satellites already in orbit, which have been delivering improved service speeds, global coverage, reliability, and security to users on land, at sea and in the air since December 2015. The fourth satellite adds further capacity to the GX network, as well as in-orbit redundancy that further upgrades the reliability and resilience of Inmarsat’s service offerings.

Because the satellite is extremely heavy at 13,400 lbs., the Falcon 9 was unable to carry enough propellant to attempt a landing of the first stage booster. This marked Inmarsat’s first flight with SpaceX.