BY SPACEFLIGHT NOW

Follow the countdown and flight of the Sea Launch Zenit 3SL rocket with the JCSAT 9 communications spacecraft. Reload this page for the latest on the mission.

THURSDAY, APRIL 13, 2006

A Japanese communications satellite to serve Southeast Asia and Hawaii took a sea-launched route to space Wednesday, blasting off aboard a 20-story rocket from a platform floating in the Pacific Ocean. Read our full story.

0122 GMT (9:22 p.m. EDT Wed.)

Robert Peckham, the interim president and general manager of Sea Launch Company, says the orbit achieved today was right on the mark.

0117 GMT (9:17 p.m. EDT Wed.)

Ground crews have detected the first signals from the JCSAT 9 spacecraft, confirming the craft is operating following today's launch into orbit.

0035 GMT (8:35 p.m. EDT Wed.)

Controllers expect to acquire the first signals from the newly-launched Lockheed Martin-made satellite in about 30 minutes via a ground tracking station in Uralla, Australia.

0033 GMT (8:33 p.m. EDT Wed.)

T+plus 63 minutes, 10 seconds. SPACECRAFT SEPARATION! The JCSAT 9 communications spacecraft has been released from the Block DM-SL upper stage to complete this 20th Sea Launch flight!

0028 GMT (8:28 p.m. EDT Wed.)

T+plus 58 minutes. Deployment of the spacecraft from the upper stage is five minutes away. During this coast period between completion of the Block DM-SL stage's burn and spacecraft separation, the stage is providing the necessary control and orientation for payload release.

0023 GMT (8:23 p.m. EDT Wed.)

T+plus 53 minutes, 18 seconds. The Block DM-SL's 11D58M main engine has shut down, completing the powered phase of todays's launch. The stage will now coast for about 10 minutes before deploying the JCSAT 9 satellite.

0020 GMT (8:20 p.m. EDT Wed.)

T+plus 50 minutes, 30 seconds. Engine pressure is normal.

0019 GMT (8:19 p.m. EDT Wed.)

T+plus 49 minutes. The upper stage engine is burning well.

0017 GMT (8:17 p.m. EDT Wed.)

T+plus 47 minutes, 46 seconds. Ignition! The Block DM-SL upper stage has restarted its engine to propel JCSAT 9 into geosynchronous transfer orbit.

0010 GMT (8:10 p.m. EDT Wed.)

T+plus 40 minutes. The rocket is flying above the central Atlantic Ocean, just a few minutes from the next engine burn.

0000 GMT (8:00 p.m. EDT Wed.)

T+plus 30 minutes. A half-hour has elapsed in today's flight. This coast will last nearly 17 additional minutes.

2348 GMT (7:48 p.m. EDT)

T+plus 18 minutes. The upper stage will coast in this orbit until the Block DM-SL reignites at T+plus 47 minutes, 45 seconds for the firing to achieve geosynchronous transfer orbit. The burn should last until T+plus 53 minutes, 15 seconds. Deployment of JCSAT 9 to complete today's launch is expected about 63 minutes after liftoff.

2344 GMT (7:44 p.m. EDT)

T+plus 14 minutes, 50 seconds. Engine cutoff. The Block DM-SL upper stage has completed its first burn, injecting the motor and attached JCSAT 9 spacecraft into a temporary parking orbit around Earth.

2342 GMT (7:42 p.m. EDT)

T+plus 12 minutes, 30 seconds. Sea Launch says the flight remains on course and normal.

2341 GMT (7:41 p.m. EDT)

T+plus 11 minutes, 30 seconds. Three minutes remain in this planned upper stage burn to reach a parking orbit of 112 x 1,480 miles.

2340 GMT (7:40 p.m. EDT)

T+plus 10 minutes, 30 seconds. The upper stage continues to burn.

2338 GMT (7:38 p.m. EDT)

T+plus 8 minutes, 44 seconds. The Block DM-SL upper stage has ignited for today's first of two firings to accelerate the spacecraft from the current suborbital trajectory to geosynchronous transfer orbit.

2338 GMT (7:38 p.m. EDT)

T+plus 8 minutes, 31 seconds. The second stage vernier engines have shut down and the spent stage has been jettisoned. It will impact the Pacific about 2,950 miles downrange from the launch platform.

2337 GMT (7:37 p.m. EDT)

T+plus 7 minutes, 8 seconds. The second stage RD-120 main engine has shut down. The vernier steering engines are still burning as designed.

2336 GMT (7:36 p.m. EDT)

T+plus 6 minutes, 50 seconds. The second stage is throttling down in preparation for engine cutoff.

2336 GMT (7:36 p.m. EDT)

T+plus 6 minutes. Second stage engine performance is normal as the motor continues to fire.

2335 GMT (7:35 p.m. EDT)

T+plus 5 minutes. No problems have been reported so far in the flight of Zenit 3SL with JCSAT 9.

2334 GMT (7:34 p.m. EDT)

T+plus 4 minutes. NASA's Tracking and Data Relay Satellite System has acquired the vehicle to receive telemetry for transmission to Sea Launch. The second stage is still firing.

2333 GMT (7:33 p.m. EDT)

T+plus 3 minutes, 15 seconds. The rocket's payload fairing, or nose cone, has been jettisoned. It protected the satellite cargo during atmospheric ascent. The nose cone will impact the Pacific about 610 miles downrange.

2333 GMT (7:33 p.m. EDT)

T+plus 3 minutes. Flight remains normal. The second stage engine is up and burning.

2332 GMT (7:32 p.m. EDT)

T+plus 2 minutes, 45 seconds. The second stage engine has been ignited for its firing.

2332 GMT (7:32 p.m. EDT)

T+plus 2 minutes, 35 seconds. The first stage RD-171 engine has shut down and the spent stage was jettisoned. It will impact the Pacific Ocean approximately 510 miles downrange from the Odyssey launch platform.

2331 GMT (7:31 p.m. EDT)

T+plus 1 minute, 45 seconds. The official liftoff time was 2329:59.126 GMT.

2331 GMT (7:31 p.m. EDT)

T+plus 1 minute, 10 seconds. The vehicle has passed through the region of maximum dynamic pressure.

2330 GMT (7:30 p.m. EDT)

T+plus 45 seconds. The 20-story Zenit 3SL rocket is riding the thrust of the first stage main engine. The Russian-made engine has four nozzles and powers the rocket for the first two-and-a-half minutes of flight.

2330 GMT (7:30 p.m. EDT)

LIFTOFF! Liftoff of the Sea Launch Zenit 3SL rocket with the JCSAT 9 communications spacecraft.

2329 GMT (7:29 p.m. EDT)

T-minus 1 minute and counting. The automated launch sequence has entered the final 60 seconds.

2327 GMT (7:27 p.m. EDT)

T-minus 3 minutes and counting. The spacecraft team has given its final "go" for launch. JCSAT 9 is ready to fly.

2325 GMT (7:25 p.m. EDT)

T-minus 5 minutes and counting. All systems appear "go" for liftoff from the Odyssey launch platform.

2321 GMT (7:21 p.m. EDT)

T-minus 9 minutes and counting. The transporter/erector arm has retracted from the rocket. The arm was used to roll the rocket out of the environmentally-controlled hangar atop the Odyssey platform and lift the rocket upright.

The arm has been lowered to the platform deck where it will be returned to the hangar and the doors closed for launch.

Fueling operations have been completed aboard the Odyssey platform. Over the past couple of hours, the rocket was loaded with kerosene propellant and cryogenic liquid oxygen. The platform was cleared of all workers prior to this hazardous activity, with all personnel moved to the Sea Launch Commander ship safely positioned about three miles away.

WEDNESDAY, APRIL 12, 2006

A Japanese telecommunications satellite is relying on the Sea Launch Zenit 3SL rocket for a smooth ride into orbit today from a floating platform stationed in the equatorial waters of the Pacific Ocean.

Liftoff of the JCSAT 9 spacecraft is scheduled for 2330 GMT (7:30 p.m. EDT). The available launch window extends 34 minutes to 0004 GMT (8:04 p.m. EDT).

The Odyssey launch platform is positioned along the Equator at 154 degrees West longitude. The rocket will fly eastward, ultimately releasing its payload high above eastern Africa.

The Sea Launch fleet reached the launch site over the weekend after steaming for more than a week from the company's home port in Long Beach, California. The ocean-going launch pad known as Odyssey set sail first, followed a few days later by the departure of the Sea Launch Commander vessel, which houses the management, official guests and launch control center.

Odyssey's ballast tanks were filled with seawater upon arrival, dropping the converted Norwegian oil-drilling platform to the launch depth of 65 feet. Control teams also commenced the standard 72-hour countdown. The Sea Launch Commander then pulled alongside Odyssey to allow workers to easily transfer between the two ships. The Zenit 3SL rocket was rolled out from its transport hangar aboard Odyssey and erected on the launch pedestal yesterday.

The three-stage Zenit booster - on its 20th flight in this configuration - will take just over an hour to complete its role to deliver the JCSAT 9 payload into a planned orbit with a low point of 1,045 miles and a high point of about 22,200 miles. The injection orbit's inclination will be zero degrees.

Over the next few weeks, JCSAT 9 will use its propulsion system to gradually raise its orbit to geostationary altitude, where its velocity will match that of Earth's rotation. The satellite will be positioned along the Equator at 132 degrees East longitude.

JSAT Corporation of Tokyo will use the spacecraft for television broadcasting, data relay and other business services across the Asia-Pacific region.

Built by Lockheed Martin, the 9,703-pound JCSAT 9 satellite is equipped with C- and Ku-band transponders, plus a mobile communications package. The A2100-AX model craft has a service life of 12 years.

Controllers will spend the final hours of today's launch countdown making final preparations to the rocket, payload and ground infrastructure. The Sea Launch Commander will pull away from the launch platform to a safe viewing distance about three miles away.

Fueling operations will get underway about two-and-a-half hours prior to the scheduled launch time. A mix of refined kerosene and liquid oxygen comprise the propellant used by all three stages of the launch vehicle.

After liftoff, the Zenit 3SL will fly downrange on a due east trajectory hugging the Equator. The first stage's Ukrainian four-chamber RD-171 engine ramps up to a maximum of 1.6 million pounds of thrust during its burn lasting two minutes, 29 seconds. After first stage separation, the second stage's RD-120 powerplant will come to life at an altitude of approximately 45 miles. During the second stage firing, the payload fairing shielding the JCSAT 9 satellite during the flight through the denser lower atmosphere will be jettisoned.

Eight minutes, 30 seconds after blastoff is the point when the second stage will separate from the Block-DM upper stage and payload. Ten seconds later, the Block-DM will ignite for a six-minute burn to place itself in a temporary parking orbit with a low point of 112 miles and a high point of 1,480 miles. After an extended coast phase, the stage will ignite again at T+Plus 47 minutes, 45 seconds to inject JCSAT 9 into its targeted geostationary transfer orbit. Spacecraft separation is expected 63 minutes after liftoff. Acquisition of signal from JCSAT 9 should occur about a half-hour later.

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