Russian Proton-M launch carrying the Inmarsat-5 F-2 satellite

International Launch Services (ILS) opened their 2015 campaign with the launch of the Russian Proton-M launch vehicle, this time carrying the Inmarsat-5 F-2 communications satellite, part of the Inmarsat Global Xpress (GX) system, on a multi-hour flight to its transfer orbit. Launch from the Baikonur Cosmodrome in Kazakhstan was on schedule at 12:31 GMT.

Credit: NASA

The Proton booster that launched the Inmarsat-5 F-2 satellite is 4.1 m (13.5 ft) in diameter along its second and third stages, with a first stage diameter of 7.4 m (24.3 ft). Overall height of the three stages of the Proton booster is 42.3 m (138.8 ft).

The Boeing Space and Intelligence Systems built Inmarsat-5 F2 communications satellite, based on the BSS-702HP Platform.

Credit: Boeing

The Proton vehicle has a heritage of over 400 launches since 1965 and is built by Khrunichev Research and State Production Center, one of the pillars of the global space industry and the majority owner of ILS.

Z7The first stage consists of a central tank containing the oxidizer surrounded by six outboard fuel tanks.

Each fuel tank also carries one of the six RD-276 engines that provide first stage power. Total first stage vacuum-rated level thrust is 11.0 MN (2,500,000 lbf).

Of a conventional cylindrical design, the second stage is powered by three RD-0210 engines plus one RD-0211 engine and develops a vacuum thrust of 2.4 MN (540,000 lbf).

Powered by one RD-0213 engine, the third stage develops thrust of 583 kN (131,000 lbf), and a four-nozzle vernier engine that produces thrust of 31 kN (7,000 lbf).

2015-02-01 11_15_09-www.ilslaunch.com_sites_default_files_I5F2MO.pdf Guidance, navigation, and control of the Proton M during operation of the first three stages is carried out by a triple redundant closed-loop digital avionics system mounted in the Proton’s third stage.

The mission is utilising a 5-burn Breeze M Supersynchronous Transfer Orbit mission design, with the first three stages of the Proton using a standard ascent profile to place the orbital unit into a sub-orbital trajectory.

From this point in the mission, the Breeze M will per-form planned mission maneuvers to advance the orbital unit first to a circular parking orbit, then to an intermediate orbit, followed by a transfer orbit, and finally to a supersynchronous transfer orbit.

Separation of the Inmarsat-5 F2 satellite is scheduled to occur approximately 15 hours, 31 minutes after liftoff.