0130 GMT (8:30 p.m. EST Tues.)

A Russian-made rocket booster malfunctioned during launch Tuesday, leaving an Arab telecommunications satellite below its intended Earth orbit and dealing a harsh blow to the commercial space industry. Read our full story.

0027 GMT (7:27 p.m. EST Tues.)

MISSION FAILURE: Today's launch of the ARABSAT 4A suffered a failure of the upper stage rocket motor. Here is the ILS statement announcing the failure:

"Khrunichev and International Launch Services regret to announce the failure of the Proton launch vehicle to put the ARABSAT 4A satellite into proper orbit for EADS Astrium and ARABSAT.

"The Proton Breeze M rocket lifted off from the Baikonur Cosmodrome at 2:10 a.m. today local time (3:10 p.m. Tuesday EST, 20:10 Tuesday GMT). Preliminary flight information indicates that the Breeze M upper stage shut down early during its planned burn sequence. As a contingency, the satellite was separated. We cannot comment on the disposition of the spacecraft at this time.

"A Russian State Commission is being formed to determine the reasons for the anomaly. In parallel with the State Commission, ILS will form its own Failure Review Oversight Board to review reasons for the anomaly and define a corrective action plan. ILS will release additional information when it becomes available.

"ILS remains committed to providing reliable, timely launch services for all its customers. To this end, ILS will work diligently with its partner Khrunichev to return Proton to flight as soon as possible."

2029 GMT (3:29 p.m. EST)

T+plus 19 minutes. ILS says the Breeze M performed its initial burn as planned.

The Breeze M upper stage and ARABSAT 4A have entered a coast period that will last until T+plus 65 minutes, 23 seconds when the stage re-ignites for a 31-minute firing. A minute after the burn ends, the Breeze M will jettison its emptied Additional Propellant Tank. The stage then re-starts at T+plus 98 minutes, 34 seconds for a three-minute burn. This will result in an orbit of 22,236 x 538 miles inclined 51.5 degrees to the equator.

A final burn lasting nearly eight minutes will occur at T+plus 3 hours, 39 minutes to raise the orbit's low point and greatly reduce the orbital inclination.

The ARABSAT 4A spacecraft will be deployed into its targeted geosynchronous transfer orbit with a high point of about 22,236 miles, a low point of approximately 1,957 miles and an inclination of 14.2 degrees. Separation of the satellite from the upper stage to complete the launch is expected at T+plus 4 hours, or 0010 GMT tonight.

We'll update this page when the next information is released from International Launch Services.

2022 GMT (3:22 p.m. EST)

T+plus 12 minutes. The Breeze M should be firing now. However, the rocket is out of range from live tracking coverage. So confirmation of this first burn won't be available in real-time.

2020 GMT (3:20 p.m. EST)

T+plus 10 minutes, 30 seconds. The third stage engine cutoff has occurred and the spent stage separated as expected. The Breeze M upper stage and attached ARABSAT 4A spacecraft are on a suborbital trajectory in preparation for the first of four planned firings by the upper stage to reach geosynchronous transfer orbit over the next four hours.

2018 GMT (3:18 p.m. EST)

T+plus 8 minutes, 30 seconds. ILS now confirms that the second stage has been jettisoned and the Proton third stage ignited as planned. Also, the payload fairing enclosing the ARABSAT 4A spacecraft atop the rocket has separated.

2015 GMT (3:15 p.m. EST)

T+plus 5 minutes. Standing by for burnout and separation of the second stage.

2014 GMT (3:14 p.m. EST)

T+plus 4 minutes. Proton has passed 90 km in altitude. Engines continuing to burn well.

2013 GMT (3:13 p.m. EST)

T+plus 3 minutes. Altitude is over 50 km now. The second stage engines are firing normally. Combustion chamber pressures in the engines are normal.

2012 GMT (3:12 p.m. EST)

T+plus 2 minutes, 20 seconds. The first stage engines have shut down and the spent stage has separated. The four second stage engines have ignited to continue boosting the vehicle to space.

2011 GMT (3:11 p.m. EST)

T+plus 90 seconds. The rocket is 21 km in altitude now.

2011 GMT (3:11 p.m. EST)

T+plus 60 seconds. The vehicle is now approaching the period of maximum dynamic pressure during its ascent through the atmosphere.

2010 GMT (3:10 p.m. EST)

T+plus 40 seconds. All six liquid-fueled engines on the first stage are firing as the rocket maneuvers to the proper heading for its climb to space.

2010 GMT (3:10 p.m. EST)

LIFTOFF! Liftoff of the Proton rocket launching the ARABSAT 4A communications spacecraft!

2008 GMT (3:08 p.m. EST)

T-minus 2 minutes. The master computer sequencer is in control of the countdown.

2005 GMT (3:05 p.m. EST)

T-minus 5 minutes. The launch readiness of the Proton core vehicle, Breeze M upper stage and ARABSAT 4A spacecraft is verified over the final minutes in the countdown.

2003 GMT (3:03 p.m. EST)

The ARABSAT 4A spacecraft is running on internal power for launch.

1956 GMT (2:56 p.m. EST)

At the launch site, the temperature is -1.8 degrees C. The Proton rocket is a hardy vehicle, so the cold weather is not a constraint to launch.

1951 GMT (2:51 p.m. EST)

T-minus 19 minutes. International Launch Services reports that the countdown is progressing to the planned liftoff time today.

TUESDAY, FEBRUARY 28, 2006

The first of two new Arab telecommunications satellites goes into space today aboard a Russian-made Proton rocket. ARABSAT 4A will be launched from pad 39 at the Baikonur Cosmodrome in Kazakhstan at 2010 GMT (3:10 p.m. EST).

The Proton M booster features three core stages that will deliver an upper stage and the payload into an initial suborbital trajectory. Beginning at liftoff, the Proton first stage's six RD-275 powerplants will push the rocket away from Earth with over two million pounds of thrust in the first two minutes of flight.

After first stage separation, four engines aboard the second stage will ignite and fire for three-and-a-half minutes before shutting down and jettisoning. The Proton's third stage will then come to life for its four-minute job, during which the protective payload fairing shielding the precious cargo will be let go after reaching the upper atmosphere.

The first ten minutes of the mission will pave the way for the work by the Breeze M upper stage, which conducts four burns to methodically propel ARABSAT 4A into the desired orbit for deployment. The stage will first reach a parking orbit a little over 100 miles high, before the remaining three steps raise altitude and reduce orbital inclination.

Spacecraft separation is due four hours after liftoff in a geosynchronous transfer orbit with a high point of about 22,236 miles, a low point of approximately 1,957 miles and an inclination of 14.2 degrees.

ARABSAT 4A's on-board propulsion system will complete the task of circularizing the orbit to an altitude of 22,300 miles along the Equator, and controllers will later command the craft to fly into an orbital slot at 26 degrees East longitude.

The 7,366-pound satellite is a Eurostar E2000+ model built by EADS Astrium. It carries 24 C-band transponders and 20 Ku-band transponders.

The Riyadh-based firm called ARABSAT with operate the satellite to provide television and Internet communications services across the Middle East.

The ARABSAT 4B spacecraft is scheduled to launch on another Proton rocket later this year.

Today's rocket flight is managed by International Launch Services, the joint U.S.-Russian group that commercially markets Atlas and Proton boosters. It will be the second ILS mission this year, following the successful Atlas 5 launch of New Horizons bound for Pluto.