The next Ariane 5 launch is targeted for mid-September carrying the Astra 2F direct-to-home television satellite for Europe, Middle East and Africa and India's GSAT-10 telecommunications spacecraft.

The Ariane 5 rocket has achieved its 50th consecutive successful launch since 2003 and the vehicle's 60th overall success in 64 flights since 1996.

Plus+34 minutes, 17 seconds. SPACECRAFT SEPARATION! The HYLAS 2 communications satellite has been released from the Ariane 5 rocket's upper stage, completing today's launch.

The HYLAS 2 spacecraft will be used by European operator Avanti Communications to extend the British firm's reach into Africa and the Middle East for broadband and high-speed, two-way data communications services.

It is headed for geostationary orbit for its 15-year mission using 24 Ka-band transponders. The craft, weighing 7,300 pounds at launch, was built by Orbital Sciences.

Plus+33 minutes, 3 seconds. The barrel-like "Sylda" payload adapter between Intelsat 20 and the HYLAS 2 satellites has been jettisoned. This has exposed HYLAS 2 for its upcoming release from the rocket.

Plus+32 minutes, 10 seconds. Ariane is 1,876 km in altitude.

Plus+31 minutes. Coming up on jettison of the rocket's dual payload adapter about two minutes from now.

Plus+29 minutes, 30 seconds. Ariane is 1,323 km in altitude.

Plus+28 minutes, 45 seconds. Ariane is 1,183 km in altitude.

Plus+28 minutes, 2 seconds. SPACECRAFT SEPARATION! The Intelsat 20 spacecraft has been released from the Ariane 5 rocket's upper stage, beginning what's planned to be a remarkably long 24-year life span.

Built by Space Systems Loral, it is equipped with 60 Ku-band, 24 C-band and one Ka-band transponders to provide a broad range of communications services for Europe, the Middle East, Russia and Asia. The 13,435-pound satellite will be maneuvered into geostationary orbit for delivery of video, telephone and data transmission services. In addition, it will beam direct-to-home television broadcasting for 20 million subscribers across Asia.

It will replace the aging Intelsat 7 satellite launched by an Ariane 4 rocket in September 1998 and Intelsat 10 deployed by a Proton in May 2001 at the orbital position of 68.5 degrees East longitude.

Plus+26 minutes, 45 seconds. Altitude is 849 km, velocity is 9.1 km/sec.

Plus+25 minutes, 25 seconds. The cryogenic upper stage for Ariane 5 has just shut down to complete its burn for today's launch. The stage will prepare for deployment of the two satellite payloads a few minutes from now.

Plus+24 minutes, 30 seconds. Ariane is 546 km in altitude and traveling at 9.24 km/sec.

Plus+23 minutes, 45 seconds. Ariane is 468 km in altitude and traveling at 9.1 km/sec.

Plus+23 minutes, 15 seconds. Two minutes of propulsion remains in the upper stage.

Plus+22 minutes, 30 seconds. Ariane is 361 km in altitude and traveling at 8.95 km/sec.

Plus+21 minutes, 30 seconds. Ariane is 295 km in altitude and traveling at 8.79 km/sec.

Plus+20 minutes, 45 seconds. Ariane is 254 km in altitude and traveling at 8.69 km/sec.

Plus+20 minutes. Just over five minutes remain in this firing of the upper stage.

Plus+19 minutes, 15 seconds. Ariane is 195 km in altitude and traveling at 8.4 km/sec.

Plus+18 minutes, 30 seconds. Ariane is 176 km in altitude and traveling at 8.35 km/sec.

Plus+17 minutes, 55 seconds. Ariane is 164 km in altitude and traveling at 8.2 km/sec.

Plus+17 minutes. Ariane is 151 km in altitude and traveling at 8.1 km/sec.

Plus+16 minutes. The vehicle is on the upward climb again. Ariane is 143.6 km in altitude and traveling at 7.95 km/sec.

Plus+15 minutes. Altitude is 140 km, velocity is 7.8 km/sec.

Plus+14 minutes. Ariane is 141 km in altitude and traveling at 7.6 km/sec.

Plus+12 minutes, 55 seconds. Ariane is 145 km in altitude and traveling at 7.43 km/sec.

Plus+11 minutes, 30 seconds. Ariane is 149.6 km in altitude and traveling at 7.2 km/sec.

Plus+11 minutes. The cryogenic upper stage motor continues to fire as the rocket starts the next portion of the trajectory where it gives up a little bit of altitude to obtain even quicker speeds.

Plus+10 minutes, 30 seconds. Ariane is 153 km in altitude and traveling at 7.1 km/sec.

Plus+9 minutes, 45 seconds. Ariane is 155 km in altitude and traveling at 7.0 km/sec.

Plus+9 minutes, 16 seconds. The upper stage of the Ariane 5 ECA rocket is up and burning to accelerate the payload into geosynchronous transfer orbit.

Plus+9 minutes, 5 seconds. The main cryogenic stage's Vulcain engine has cut off and the spent stage has separated. It will fall back into the atmosphere.

Plus+8 minutes, 30 seconds. Ariane is 156 km in altitude and traveling at 6.3 km/sec.

Plus+8 minutes. Coming up on main stage shutdown in about one minute. Velocity is 5.8 km/sec.

Plus+7 minutes, 35 seconds. Ariane is 160.7 km in altitude and traveling at 5.2 km/sec.

Plus+7 minutes. The rocket's climb has leveled out as designed. This temporary trajectory is needed in order to gain speed.

Plus+6 minutes, 50 seconds. Ariane is 163 km in altitude and traveling at 4.4 km/sec.

Plus+6 minutes. The main stage's Vulcain 2 engine continues to fire as it burns a mixture of liquid hydrogen and liquid oxygen rocket fuel.

Plus+5 minutes, 30 seconds. Ariane is 158 km in altitude and traveling at 3.4 km/sec.

Plus+3 minutes, 45 seconds. Ariane remains right on course. The rocket is 124 km in altitude and traveling at 2.45 km/sec.

Plus+3 minutes, 19 seconds. Separation of the rocket's nose cone has been confirmed, uncovering the Intelsat 20 satellite in its upper position in the dual payload stack.

Plus+2 minutes, 45 seconds. The vehicle is 87 km in altitude, traveling at 2.11 km/sec.

Plus+2 minutes, 23 seconds. The solid rocket boosters have been jettisoned from the Ariane 5 rocket's core stage. The liquid-fueled Vulcain 2 main engine continues to fire to propel the vehicle and its satellite payload to space.

Plus+2 minutes. A beautiful late-afternoon ascent by Ariane 5!

Plus+1 minute, 30 seconds. Less than a minute left in the burn by the solid rocket boosters. The boosters are providing 90 percent of the liftoff thrust.

Plus+60 seconds. The vehicle continues tracking on the proper heading as it rides the power of the twin solid rocket boosters and main stage liquid-fueled engine.

Plus+35 seconds. Pitch and roll maneuvers has been performed by the Ariane 5 vehicle to position itself on the correct eastward trajectory bound for its highly elliptical orbit to drop off two commercial telecommunications satellites.

LIFTOFF! Liftoff of the Ariane 5 carrying its heaviest payload to geosynchronous transfer orbit, the pairing of Intelsat 20 and HYLAS 2!

Minus-50 seconds. The vehicle is running on internal power.

Minus-1 minute. Final events leading to launch will begin at Minus-37 seconds when the automated ignition sequence is started. The water suppression system at the launch pad will start at Minus-30 seconds. At Minus-22 seconds, overall control will be given to the onboard computer. The residual hydrogen burn flares will fire beneath the Vulcain engine at Minus-6 seconds to burn away any free hydrogen gas. At Minus-3 seconds, onboard systems take over and the two inertial guidance systems go to flight mode. Vulcain main engine ignition occurs at Minus-0 seconds with checkout between Plus+4 and 7 seconds. If there are no problems found, the solid rocket boosters are ignited at Plus+7.0 seconds for liftoff at Plus+7.3 seconds.

Minus-2 minutes. The Vulcain 2 main engine supply valves are being opened. And the ground valves for engine chilldown are being closed.

Minus-3 minutes. The upper stage cryogenic tanks are charging to flight pressures. And the scheduled launch time has been loaded into the rocket's main computer system.

Minus-4 minutes. Pressurization is now underway for the main stage's liquid oxygen and hydrogen tanks. Also, final pyrotechnic arming is starting.

Minus-5 minutes. Still heading for an on-time launch.

Minus-6 minutes and counting. Liquid hydrogen and liquid oxygen supplies of the main and upper cryogenic stages are being topped off at flight levels. Also, the pyrotechnic line safety barriers are being armed.

Minus-7 minutes and counting. The Synchronized Sequence is starting. Computers are now in control of this final segment of the launch countdown to prepare the rocket and ground systems for liftoff. There are two computers running the countdown -- one aboard the Ariane 5 and a redundant one at the ELA-3 launch complex.

Minus-10 minutes and counting. Still all green across the status board in launch control as the countdown heads for the Synchronous Sequence.

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Minus-12 minutes and counting. No launch constraints are being reported with the Ariane rocket, its double satellite payload, ground systems or the weather. The Synchronized Sequence will assume control of the clock at 2047 GMT to govern the final seven minutes to launch.

Minus-15 minutes and counting. With this launch of Intelsat 20, there will be 72 Space Systems/Loral-built satellites currently in orbit and HYLAS will make it 27 for the Orbital-built GEOStar commercial geosynchronous spacecraft product line.

Minus-20 minutes and counting. Today's mission represents the 64th launch for the Ariane 5 rocket dating back to 1996 and the fourth this year. It is the 208th flight overall for the Ariane family of launchers since 1979.

What's more, it is the 53rd Intelsat spacecraft launched by Arianespace since 1983 and Ariane 5 has lofted both HYLAS spacecraft for emerging operator Avanti Communications.

Welcome to our live launch coverage of Ariane 5 with the Intelsat 20 and HYLAS 2 payloads. Liftoff remains scheduled for 2054 GMT from the Guiana Space Center in Kourou, French Guiana on the northeastern coast of South America.

The Ariane 5 rocket is fully fueled, weather is GO and no technical problems are being reported in the countdown.

The Intelsat payload customer reports weather conditions are acceptable in Kourou at the Guiana Space Center and fueling of the Ariane 5 rocket is underway for today's launch.

Raising the bar on the amount of cargo it can carry, Europe's commercial Ariane 5 rocket will launch into orbit today a pair of telecommunications satellites weighing over 20,000 pounds.

Traveling the 1.7-mile trek on rails, the 16-story-tall Ariane 5 was rolled out Wednesday from its final assembly building where the two payloads had been mounted atop the vehicle.

Today's liftoff, unleashing 2.6 million pounds of thrust from its hydrogen-fueled main stage and twin solid rocket boosters, is scheduled for 4:54 p.m. EDT (2054 GMT). The day's available launch window extends 57 minutes.

Join is for live updates and streaming video of the launch on this page starting about 20 minutes before liftoff time.

Bound for a typical geosynchronous transfer orbit, the rocket will first deploy the Intelsat 20 spacecraft to provide communications capabilities across Europe, the Middle East and Russia and Asia and then release the HYLAS 2 satellite for high-speed data services across all of Europe, Africa and the Middle East.

The two satellites, plus the dual-payload adapter equipment amount to 22,448 pounds, including 20,735 pounds just for the two spacecraft. That is a new weight record for Ariane 5 going to geosynchronous transfer orbit.

The countdown clock was started by Arianespace at 4:24 a.m. EDT and a complete check of electrical systems occurred at 8:30 a.m. EDT.

Fueling of the Ariane 5 with super-cold liquid hydrogen and liquid oxygen propellants begins at 12:04 p.m. EDT. First, ground reservoirs will be pressurized, then the fuel lines will be chilled down to condition the plumbing for the flow of super-cold liquid hydrogen and liquid oxygen, which are stored at minus 423 degrees Fahrenheit and minus 298 degrees Fahrenheit, respectively.

It will take approximately two hours to fill the tanks contained within the rocket's main stage.

A similar procedure for the Ariane 5's cryogenic upper stage will commence at 1:04 p.m. EDT.

Chilldown conditioning of the Vulcain 2 first stage engine will occur at 1:34 p.m. EDT, and a communications check between the rocket and ground telemetry, tracking and command systems is scheduled for 3:44 p.m. EDT.

The computer-controlled synchronized countdown sequence will begin seven minutes before launch to pressurize propellant tanks, switch to onboard power and take the rocket's guidance system to flight mode.

The Vulcain 2 main engine ignites as the countdown reaches zero, followed by a health check and lighting the Ariane 5's solid rocket boosters seven seconds later to send the 1.7-million-pound launcher skyward.

Five seconds after blastoff, the rocket will begin pitching east from the ELA-3 launch pad, surpassing the speed of sound less than a minute into the mission. The pair of solid rocket boosters will jettison at T+plus 2 minutes and 21 seconds some 42 miles in altitude.

Once above the dense atmosphere, the launcher's payload fairing will fall away more than three minutes into flight at an altitude of 68 miles. The Ariane 5's first stage will shut down at T+plus 8 minutes, 57 seconds, followed moments later by stage separation and ignition of the hydrogen-fueled cryogenic HM7B upper stage engine all at altitude of 97 miles.

The rocket's upper stage will fire for nearly 16 minutes, accelerating to a velocity of 20,920 miles per hour to reach an elliptical orbit with an advertised high point of 22,328 miles, a low point of 155 miles and inclination of 6 degrees relative to the equator.

The release of Intelsat 20 is scheduled for T+plus 28 minutes, 1 second. The rocket's barrel-like Sylda 5 dual-payload adapter will be jettisoned 33 minutes into the flight to uncover the second passenger.

HYLAS 2 will separate from the lower portion of the payload stack at T+plus 34 minutes, 17 seconds, capping the ascent.