Proton-M launches with DirecTV 12 satellite

by Chris Bergin

International Launch Services (ILS) have launched the DirecTV 12 telecommunications satellite via their veteran Proton-M launch vehicle and Breeze-M upper stage late on Monday, marking the final orbital launch of 2009. Lift-off from the Baikonur Cosmodrome in Kazakhstan was on time at 19:22 EST, ahead of over nine hours of flight until the spacecraft was successfully released into orbit.

Proton Launch Preview:

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 Proton and the Breeze M are built by Khrunichev State Research and Production Space Center.

The Proton M launch vehicle, utilizing a 5-burn Breeze M mission design, will lift off from Pad 39 at Baikonur Cosmodrome, Kazakhstan, with the DIRECTV 12 satellite on board.

The first three stages of the Proton will use a standard ascent profile to place the Ascent Unit (payload fairing, Breeze M upper stage and the DIRECTV12 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 geo-transfer orbit.

Separation of the DIRECTV 12 satellite is scheduled to occur approximately 9 hours, 12 minutes after lift-off.

The DIRECTV 12 next-generation satellite will become operational in the first half of next year, which will result in expanding DirecTV’s HD capacity by 50 percent to more than 200 national channels.

The 131-transponder payload integrates 32 active and 12 spare TWTAs (Traveling Wave Tube Amplifiers) at Ka-band for national service and 55 active and 15 spare TWTAs for spot beams. The payload is powered by a gallium arsenide solar array that spans more than 48 meters.

DIRECTV 12 will receive and transmit programming throughout the United States with two large Ka-band reflectors, each measuring 2.8 meters in diameter and nine other Ka-band reflectors.

“Boeing has provided advanced satellite systems to DIRECTV for more than 16 years, and we are on track for a DIRECTV launch that will deliver superior commercial communications capabilities to our customer and help their business succeed through the use of Boeing technology,” noted Craig Cooning, vice president and general manager of Boeing Space and Intelligence Systems.

“The successful launch and deployment of DIRECTV 12 will bring the best in digital television programming to DIRECTV’s more than 18.4 million customers across the United States.”

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