ILS Proton-M successfully launches with Orbital-built SES-1 satellite

by Chris Bergin

International Launch Services (ILS) have launched the SES-1 telecommunications satellite via their veteran Proton-M launch vehicle and Breeze-M upper stage on Saturday. Lift-off from the Baikonur Cosmodrome in Kazakhstan was on time at 11:19 GMT, ahead of over nine hours of flight until the spacecraft was successfully released into orbit.


The Proton booster 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 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 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). 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 Breeze-M upper stage is the Phase III variant, which is the second flight of the new configuration for the avionics bay. The Phase III upgrade uses two new high-pressure tanks (80 liters) to replace six smaller tanks, along with the relocation of command instruments towards the centre – in order to mitigate shock loads when the additional propellant tank is being jettisoned.

The Proton M launch vehicle, utilizing a 4-burn Breeze M mission design, will lift off from Pad 39 at Baikonur Cosmodrome, Kazakhstan, with the SES-1 satellite on board.

The first three stages of the Proton will use a standard ascent profile to place the orbital unit (Breeze M upper stage and the SES-1 satellite) into a sub-orbital trajectory.

From this point in the mission, the Breeze M will perform 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 near geostationary orbit.

Separation of the SES-1 satellite is scheduled to occur approximately 8 hours, 58 minutes after liftoff.


SES-1 is the 26th satellite in the SES WORLD SKIES fleet, which is part of the 42 spacecraft constellation of parent company SES. The satellite replaces AMC-2 and AMC-4 at 101 degrees west longitude, delivering communications services to customers in the enterprise, government and media sectors from the center of the North American arc.

The satellite powers networks encompassing thousands of VSAT terminals, and delivers high-definition video channels that constitute part of SES WORLD SKIES’ extensive HD-PRIME television neighborhood.

SES-1 is the first of a new generation of SES WORLD SKIES satellites bearing the ‘SES’ name, joining the existing line of AMC satellites over North America and the NSS satellites covering the rest of the world.

Built by Orbital Sciences Corporation, the 3,170 kg (6,989 lb) satellite sports 24 Active C-band transponders, 24 Active Ku-band transponders, and has an anticipated service life of 16 years.

Technical stats for the birds include a C-Band Repeater of two groups of 16-for-12 SSPAs, SSPA Power: 20 W RF, with Antennas of 2.3m dual gridded shaped deployable reflector. Its Ku-Band Repeater is two groups of 16-for-12 linearized TWTAs, TWTA Power: 90 W RF, and a 2.3m dual gridded shaped deployable reflector. The SES fleet utilize 3-axis stabilization.

The SES-1, -2 and -3 satellites are being built for SES WORLD SKIES under a contract for up to five virtually identical satellites. The spacecraft are hybrid C- and Ku-band spacecraft that will serve the Continental United States and will replace satellites currently in orbit.

Saturday’s launch is the third ILS Launch in 2010, the fifth Proton launch in 2010, the 59th Proton launch for ILS, 17th SES Group Satellite launched with ILS Proton, and the third Orbital Satellite Launched with ILS.

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