LAUNCH SUCCESS! The Breeze M upper stage has accomplished its job, carrying Yahsat 1B into geosynchronous transfer orbit and deploying the satellite tonight.

The final six-minute push was delivered by the Breeze M main engine while flying high over the Indian Ocean a short time ago. The craft was successfully released a few minutes later to complete the long launch sequence.

Y1B begins a life of serving high-speed Internet links to 27 countries across the Middle East, Africa and Southwest Asia, plus providing secure governmental communications for the United Arab Emirates.

Operated by Al Yah Satellite Communications Company, or Yahsat, of Abu Dhabi, the Y1B spacecraft will bring the new YahClick service to life, offering customers with uninterrupted broadband Internet.

Built in collaboration between Thales Alenia Space and Astrium Space with a launch weight of nearly 13,000 pounds, the Y1B is outfitted with a Ka-band communications package to generate 61 narrow spot beams over its coverage area.

"We are delighted to see this milestone in our business plan reached with the launch of Y1B. With the satellite in orbit, we are on track in our mission to connect communities around the region with reliable, affordable broadband services through our 'YahClick' service. Communications is a vital factor for economic and social growth in today's world and we are very excited to be bringing this pioneering vision into reality," said Yahsat CEO, Tareq Abdel Raheem Al Hosani.

The craft is equipped with conventional chemical engines and four electrical propulsion plasma thrusters to maneuver into a circular geostationary orbit at 47.6 East longitude.

It joins the Y1A bird launched last April to provide such telecommunications services as high-definition television relay.

Today represented the 72nd commercial Proton mission under the guidance of International Launch Services and the third this year.

The next Proton rocket launch is slated for mid-May with the Canadian Nimiq 6 direct-to-home TV broadcasting spacecraft.

The upper stage and attached Y1B satellite are currently in the midst of a five-hour coast period prior to the fifth and final firing by the Breeze M tonight.

International Launch Services reports that the third and four burns took place as planned. The maneuvers included an 11-minute firing, then a pause to jettison the now-emptied extra fuel tank, followed by a six-minute engine firing as the rocket flew over South America and the Atlantic Ocean.

Breeze M now resides in a highly inclined, highly elliptical orbit, with a targeted low point of 267 miles, a high point of 22,248 miles and inclination of 49.1 degrees relative to the equator.

One final burn remains later tonight to raise the orbit's low point to 2,451 miles and substantially reduce the inclination to 23.8 degrees.

Spacecraft separation to complete the launch is expected at 0730 GMT (3:30 a.m. EDT).

The second burn has been conducted by the Breeze M upper stage, boosting the rocket and its Y1B payload from the initial low-altitude circular parking orbit of about 107 miles at 51.5 degrees inclination.

This latest firing, lasting almost 18 minutes over the Atlantic Ocean and Africa as the vehicle was nearing completion of the first orbit, was designed to raise the altitude.

The new intermediate orbit is elliptical in nature, with a targeted low point of 168 miles, a high point of 3,107 miles and inclination of 50.3 degrees relative to the equator.

Breeze M now coasts until around 0146 GMT (9:46 p.m. EDT) when the next two burns occur back-to-back with only a brief pause in between to shed the donut-like auxiliary propellant tank.

The Breeze M upper stage and Y1B are now in a coast period that will last until T+67 minutes, 30 seconds. That is when the stage re-ignites for a 17-minute, 46-second burn.

A third firing will begin at T+plus 3 hours, 28 minutes and last for 11 minutes. Following completion of its third burn of the mission, the Breeze M will jettison its emptied Additional Propellant Tank. The stage then restarts at T+3 hour, 41 minutes for a six-minute firing.

A final six-minute burn will occur at T+plus 8 hours, 53 minutes to finish shaping the orbit.

Spacecraft separation to complete the launch is targeted to occur at T+plus 9 hours, 12 minutes, or 0730 GMT (3:30 a.m. EDT).

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International Launch Services reports that the first burn of Breeze M was successfully completed to put the vehicle into a preliminary parking orbit. Today's mission is going according to plan.

Telemetry confirms that the third stage finished firing and jettisoned, finishing the Proton M rocket's role in the ascent. The Breeze M upper stage now must perform its five burns.

T+plus 9 minutes. The third stage should complete its burn in about a minute, followed by separation of the spent motor. The Breeze M and attached Y1B spacecraft will then be on a suborbital trajectory in preparation for the first of five planned firings by the upper stage to reach geosynchronous transfer orbit over the next several hours.

T+plus 7 minutes. Second stage separation has occurred and ignition of the Proton third stage has been confirmed. Also, the payload fairing enclosing the Y1B spacecraft atop the rocket has separated.

T+plus 2 minutes, 10 seconds. The six main engines on the first stage have extinguished and the spent stage just separated. Now, the four second stage engines are up and burning as planned.

LIFTOFF! Liftoff of the Russian Proton rocket launching a powerful Ka-band communications satellite for Yahsat and the Middle East!

T-minus 60 seconds. All systems remain "go" for liftoff at the precise and instantaneous launch time a minute from now.

T-minus 2 minutes. The countdown is being run by a master computer sequencer.

T-minus 5 minutes. The launch readiness of the Proton core vehicle, Breeze M upper stage and Y1B spacecraft will be verified over the next few minutes in the countdown.

T-minus 10 minutes and counting. The Proton rocket weighs 1,554,000 pounds as it sits on the launch pad. The Y1B spacecraft accounts for about 13,000 pounds of the weight.

T-minus 12 minutes and counting. At launch the Proton's six first stage engines will fire together to propel the 191-foot-tall rocket into the middle-of-the-night sky at Baikonur. Liftoff is scheduled for 4:18 a.m. local time at Baikonur.

Weather conditions are within limits for today's Proton launch. The latest report at Baikonur indicates mostly clear skies, good visibility, a temperature in the low 50s F and easterly winds of 13 to 20 mph.

Here's a look at some stats about today's mission. This will be:

• 376th Proton rocket launch since 1965
• 72th International Launch Services Proton
• 55th Proton M using a Breeze M upper stage since 2001
• 3rd Proton of 2012
• 14th Eurostar satellite on ILS Proton
• 1st Yahsat satellite launch on ILS Proton

Retraction of the launch pad's mobile service tower from the Proton rocket has begun as preparations continue for today's ascent of the Y1B communications satellite.

The three-stage Proton core vehicle and Breeze M upper stage are fully fueled, a process that began about six hours before launch time. Liftoff remains scheduled for 2218 GMT (6:18 p.m. EDT) from the Baikonur Cosmodrome in Kazakhstan.

The six engines on the Proton first stage will ignite at launch to push the 19-story rocket away from Earth on two million pounds of thrust. After first stage separation two minutes into flight, four engines aboard the second stage fire for three-and-a-half minutes before shutting down and jettisoning. The Proton's third stage then comes to life for its four-minute job, during which time the protective payload fairing shielding Y1B will separate.

The Breeze M upper stage then assumes control of the mission to conduct a series of five critical burns spread across nine hours to propel the payload into the proper orbit by tonight.

The Russian State Commission has granted approval for fueling and launching the Proton rocket today carrying a Middle Eastern spacecraft for high-data-rate communications.

Launch of the Proton M booster fitted with a Breeze M upper stage carrying the Yahsat 1B satellite cargo is scheduled for 2218 GMT (6:18 p.m. EDT) from pad 39 at Baikonur Cosmodrome in Kazakhstan.

Watch this page for live updates and streaming video coverage beginning at 2200 GMT (6 p.m. EDT).

The payload will become the second craft for operator Yahsat of Abu Dhabi, United Arab Emirates, providing both commercial and governmental services over the Middle East, AFrica and Southwest Asia.

Built in collaboration between Thales Alenia Space and Astrium Space with a launch weight of nearly 13,000 pounds, the Y1B is outfitted with a Ka-band communications package to generate 61 narrow spot beams over its coverage area for Internet links and secure communications.

The climb to orbit will be another of the Proton/Breeze M vehicle's marathons. The lower three stages of the Khrunichev-built Proton will fire during the mission's first 10 minutes. Five burns of the Breeze M upper stage will follow over the next nine hours to reach the targeted geosynchronous transfer orbit for release of Y1B.

The rocket's flight is managed by International Launch Services, the Proton's chief marketer to commercial satellite companies. It will be the 72nd ILS Proton dating back the past 16 years.

The lower Proton stages leave the combined upper stage and Y1B vehicle on a suborbital trajectory. The first Breeze M firing is needed to achieve a temporary parking orbit around Earth at an altitude of 107 miles, inclined 51.5 degrees.

The next four Breeze M firings will methodically raise the orbit and reduce inclination before deploying the Y1B spacecraft into an orbit with an apogee of 22,236 miles, perigee of 2,451 miles and inclination of 23.8 degrees.

The rocket's separation from the satellite is expected at 0730 GMT (3:30 a.m. EDT) to complete the launch sequence.

Y1B will rely upon its onboard engine and electrical propulsion plasma thrusters to reach a circular geostationary orbit 22,300 miles above the planet where it can match Earth's rotation and appear fixed along the equator.

Check this page during the launch for live updates on the mission's progress.

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