2330 GMT (7:30 p.m. EDT)
Sea Launch delivered a 6.6-ton European telecommunications satellite to orbit Monday after a dazzling liftoff of a Ukrainian-built Zenit 3SL rocket, marking the commercial launch company's first mission since February 2013.

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2223 GMT (6:23 p.m. EDT)
Sea Launch and Eutelsat confirm acquisition of the Eutelsat 3B spacecraft after today's successful launch. Ground stations are now in communication with the satellite.
2217 GMT (6:17 p.m. EDT)
Sea Launch reports today's mission put Eutelsat 3B into an accurate orbit, with an apogee just 12.9 kilometers, or 8 miles, higher than planned and a perigee right on the mark.
2204 GMT (6:11 p.m. EDT)
Eutelsat 3B separation! The 13,155-pound communications satellite has been released into geosynchronous transfer orbit by Sea Launch's Block DM-SL upper stage. The rocket was aiming to deploy Eutelsat 3B with a perigee of 381 kilometers, or 236 miles, an apogee of 35,799 kilometers, or 22,244 miles, and an inclination of 0 degrees.
2204 GMT (6:04 p.m. EDT)
Separation of the Eutelsat 3B satellite is scheduled for T+plus 1 hour, 37 seconds, as it flies over the Indian Ocean.
2201 GMT (6:01 p.m. EDT)
T+plus 51 minutes. The Block DM-SL's 11D58M main engine has shut down, completing the powered phase of today's launch. The stage will now coast for approximately 10 minutes before deploying the Eutelsat 3B satellite.
2157 GMT (5:57 p.m. EDT)
T+plus 47 minutes. Now about halfway through the second burn of the Block DM-SL upper stage. All parameters are reported normal.
2154 GMT (5:54 p.m. EDT)
T+plus 44 minutes. The upper stage has reignited to send Eutelsat 3B into geosynchronous transfer orbit.
2140 GMT (5:40 p.m. EDT)
T+plus 30 minutes. The second burn of the Block DM-SL upper stage is scheduled to begin at 2143 GMT (5:43 p.m. EDT) and last 6 minutes, 57 seconds.
2126 GMT (5:26 p.m. EDT)
T+plus 16 minutes. The Block DM-SL and Eutelsat 3B are flying east along the equator, traversing South America in the next few minutes before the upper stage engine reignites over Africa at T+plus 43 minutes, 50 seconds.
2123 GMT (5:23 p.m. EDT)
T+plus 13 minutes, 30 seconds. The Block DM-SL upper stage has completed its first burn, which was designed to inject the motor and attached Eutelsat 3B spacecraft into a temporary parking orbit around Earth.
2122 GMT (5:22 p.m. EDT)
T+plus 12 minutes. The Block DM-SL engine generates about 18,000 pounds of thrust consuming kerosene and liquid oxygen propellants.
2120 GMT (5:20 p.m. EDT)
T+plus 10 minutes. This Block DM-SL burn will put Eutelsat 3B into a parking orbit a few hundred miles above Earth. It's scheduled to last approximately 4 minutes, 39 seconds.
2118 GMT (5:18 p.m. EDT)
T+plus 8 minutes, 50 seconds. The Zenit's second stage has switched off its vernier steering engine and separated, and the Block DM-SL upper stage has ignited for today's first of two firings to propel the Eutelsat 3B spacecraft from the current suborbital trajectory to geosynchronous transfer orbit.
2117 GMT (5:17 p.m. EDT)
T+plus 7 minutes, 20 seconds. The second stage RD-120 main engine has shut down, but the vernier steering engine continues to fire for another minute or so.

NASA's Tracking and Data Relay Satellite System has acquired the vehicle's signal to receive telemetry for transmission to Sea Launch ground engineers.

2117 GMT (5:17 p.m. EDT)
T+plus 7 minutes. The second stage engine is throttling down in preparation for shutdown.
2116 GMT (5:16 p.m. EDT)
T+plus 6 minutes. The rocket's second stage continues firing with no problems reported. Pressure and trajectory are reported to be nominal.
2114 GMT (5:14 p.m. EDT)
T+plus 4 minutes. The Zenit's 13.4-foot-diameter Boeing-built payload fairing has been jettisoned.
2112 GMT (5:12 p.m. EDT)
T+plus 2 minutes, 50 seconds. The first stage RD-171M engine has shut down and the spent stage was jettisoned. The second stage main engine and vernier engine are now firing.
2112 GMT (5:12 p.m. EDT)
T+plus 2 minutes, 30 seconds. The first stage RD-171M engine has shut down and the spent stage was jettisoned.
2111 GMT (5:11 p.m. EDT)
T+plus 1 minute, 50 seconds. Official liftoff time was marked at 2109:59.119 GMT.
2111 GMT (5:11 p.m. EDT)
T+plus 1 minute, 15 seconds. The vehicle has passed through the region of maximum dynamic pressure.
2110 GMT (5:10 p.m. EDT)
T+plus 30 seconds. The 20-story rocket is riding the thrust of the first stage main engine as it powers into the equatorial skies. The Russian-made engine has four nozzles and propels the rocket for the first two-and-a-half minutes of flight.
2110 GMT (5:10 p.m. EDT)
Liftoff of the Sea Launch Zenit 3SL rocket with Eutelsat 3B, a communications satellite to link four continents.
2109 GMT (5:09 p.m. EDT)
T-minus 60 seconds.
2108 GMT (5:08 p.m. EDT)
T-minus 2 minutes. Current temperature at the launch site is 82 degrees Fahrenheit, with 5-foot seas and winds of about 11 knots. All systems remain go as the automated countdown sequence continues.
2106 GMT (5:06 p.m. EDT)
T-minus 4 minutes. The hangar doors have closed now that the transporter/erector is safely inside.
2105 GMT (5:05 p.m. EDT)
T-minus 5 minutes. Everything remains on track for launch at 2110 GMT (5:10 p.m. EDT). Follow the flight with this launch timeline.
2102 GMT (5:02 p.m. EDT)
T-minus 8 minutes. Eutelsat 3B will provide C-band, Ku-band and Ka-band communications services over Europe, Africa, the Middle East, Central Asia and Latin America.
2100 GMT (5:00 p.m. EDT)
T-minus 10 minutes. The transporter/erector arm has retracted away from the 20-story Zenit rocket and is slowly rolling into the Odyssey platform's hangar, where the doors will close to protect the equipment from the launch.

The retraction of the transporter/erector is an automated process. Personnel evacuated from the Odyssey launch platform several hours ago before the start of fueling and are now safely positioned on the Sea Launch Commander control ship three miles uprange.

The Eutelsat 3B spacecraft is now confirmed to be on internal battery power.

2054 GMT (4:54 p.m. EDT)
T-minus 16 minutes. Sea Launch's live video stream from the launch site has begun.

The transporter/erector arm positioned against the Zenit rocket will soon back away and retract into a protected hangar on the Odyssey launch platform.

2052 GMT (4:52 p.m. EDT)
T-minus 18 minutes. Loading of liquid oxygen into the Zenit 3SL rocket should be wrapping up at this time.
2051 GMT (4:51 p.m. EDT)
T-minus 19 minutes. The Eutelsat 3B satellite payload nestled in the Sea Launch rocket's nose cone has transitioned to internal battery power for liftoff.
2035 GMT (4:35 p.m. EDT)
T-minus 35 minutes. The launch team just completed final readiness poll, and all stations reported clearance to launch Eutelsat 3B at 2110 GMT (5:10 p.m. EDT).

Loading of kerosene fuel into the three-stage rocket is now complete. Liquid oxygen supplies continue to flow into the rocket to replenish the cryogenic oxidizer as it boils off.

2030 GMT (4:30 p.m. EDT)
T-minus 40 minutes. The Eutelsat 3B satellite is reported in good condition.

Some statistics on today's launch:

2010 GMT (4:10 p.m. EDT)
T-minus 60 minutes. The countdown continues with no problems reported by Sea Launch. The launch team has authorized final payload preparations for liftoff.

Weather conditions are predicted to be favorable at launch time.

1930 GMT (3:30 p.m. EDT)
Kerosene fuel is now being pumped inside the Zenit 3SL rocket. The three stages of the rocket will be filled with more than 900,000 pounds of propellant.
1910 GMT (3:10 p.m. EDT)
T-minus 2 hours. Tanking operations have begun to load propellant into the three-stage rocket.

Liquid oxygen loading began around 1850 GMT (2:50 p.m. EDT), and refined kerosene fuel will begin flowing into the launcher shortly. All three stages of the Zenit 3SL rocket burn liquid oxygen and kerosene propellants.

1710 GMT (1:10 p.m. EDT)
T-minus 4 hours. Sea Launch reports the weather outlook is favorable for today's blastoff from the equator at 2110 GMT (5:10 p.m. EDT).

Preparations are underway to load liquid oxygen propellant into the three-stage Zenit 3SL rocket, and the final workers have been evacuated from the Odyssey launch platform.

The Sea Launch Commander control ship is safely positioned about 3 miles from the Odyssey platform for the final countdown. The workers evacuate the platform via helicopter to the command ship.

1415 GMT (10:15 a.m. EDT)
With its mobile command ship and launch platform positioned in the equatorial Pacific Ocean, Sea Launch is counting down to its first mission since February 2013 on Monday with a European communications satellite.

The company's Odyssey platform and Sea Launch Commander control vessel arrived at the Pacific launch site last week, and the launch team initiated a 72-hour countdown Friday before hoisting the Zenit 3SL booster on Odyssey's launch pad over the weekend.

The ships sailed from Sea Launch's home port in Long Beach, Calif., to the launch site at the equator and 154 degrees west longitude, about 1,400 miles south of Hawaii.

Fueling of the Zenit 3SL rocket with kerosene and liquid oxygen will begin a few hours before liftoff, which is set for 2110 GMT (5:10 p.m. EDT; 2:10 p.m. PDT) at the opening of a 54-minute launch window.

The 20-story rocket is due to make its first launch for Sea Launch since a rocket failure destroyed an Intelsat communications satellite moments after liftoff Feb. 1, 2013.

Investigators blamed the mishap on a failure in a hydraulic steering pump attached to the Zenit rocket's first stage RD-171M main engine.

After engineers instituted corrective actions at Yuzhmash, the rocket's prime contractor and supplier of the hydraulic steering unit, a Zenit launcher notched a successful flight with Israel's Amos 4 communications satellite from the Baikonur Cosmodrome on Aug. 31, 2013.

Monday's mission is the first Zenit flight conducted by Sea Launch since the launch failure last year.

"All the corrective actions that were provided by the [investigative] commission to Yuzhmash have already taken place, and there were some processes that have been adapted accordingly," said Sergey Gugkaev, CEO of Switzerland-based Sea Launch. "The other important point that we agree on with our Yuzhmash colleagues was for a more concise and more detailed quality review that will be implemented from now on. There was already a Zenit launch in August of 2013, which was basically the return-to-flight for almost the same rocket, which had the same hydraulic power supply."

The Zenit 3SL rocket will fly east from the Odyssey launch pad after liftoff Monday, powered by 1.6 million pounds of thrust from its RD-171 main engine. The booster will fly along the equator, getting an extra boost in velocity from the speed of Earth's rotation, one of the advantages of Sea Launch's base in the equatorial Pacific.

The two-stage Zenit rocket, designed by Yuzhnoye and built by Yuzhmash in Ukraine, will fire for eight-and-a-half minutes before yielding to a Russian Block DM-SL upper stage to place Eutelsat 3B in a geosynchronous transfer orbit.

Two burns of the Block DM-SL upper stage are planned before separation of Eutelsat 3B one hour after liftoff as it flies over the Indian Ocean.

The launcher will target an orbit with a low point of 239 miles, a high point of 22,143 miles, and an inclination of 0 degrees, according to Sea Launch, which is 95 percent owned by Russian aerospace contractor RSC Energia.

The launch of Eutelsat 3B will mark the 36th flight for Sea Launch since 1999.

Eutelsat 3B will use an on-board engine to boost itself to a circular orbit 22,300 miles above Earth, guiding the craft to an operational location at 3 degrees east longitude. Satellites in geostationary orbit circle Earth at the same speed as the planet's rotation, causing them to hover over a fixed location.

Built by Airbus Defence and Space, the spacecraft is owned by Paris-based Eutelsat, one of the world's top commercial telecom satellite operators. Eutelsat 3B is based on the Airbus Eurostar E3000 satellite platform.

The 13,155-pound satellite carries 51 C-band, Ku-band and Ka-band transponders in a unique tri-band configuration to beam data, telecom, broadband, and professional video services to users in Europe, Africa, the Middle East, Central Asia and South America, according to Eutelsat.

The C-band and Ku-band payload will focus on television broadcasting and data markets, while the Ka-band transponders -- connected to steerable beams -- are tailored for high-bandwidth markets.

Eutelsat 3B will replace Eutelsat 3D in the 3 degrees east location, allowing Eutelsat 3D to be repositioned to serve other markets.

Fitted with 10 antennas, Eutelsat 3B is designed for a 15-year lifetime.