BY JUSTIN RAY

Follow the countdown and flight of the Sea Launch Zenit 3SL rocket with the DirecTV 7S spacecraft. Reload this page for the very latest on the mission.

TUESDAY, MAY 4, 2004

Dozens of communities across America will receive local network television programming via a satellite successfully launched into space Tuesday where it joins a fleet of direct-to-home broadcasting craft operated by DirecTV. Read our full story.

1340 GMT (9:40 a.m. EDT)

Originally slated to fly aboard an Ariane 5 rocket, DirecTV 7S was transferred to Sea Launch due to scheduling conflicts in the Arianespace manifest.

The switch was performed within the Launch Services Alliance created last July by Arianespace, Sea Launch marketer Boeing Launch Services and Mitsubishi Heavy Industries of the Japanese H-2A rocket program.

"We congratulate our partners at Boeing Launch Services and the entire Sea Launch team on today's successful launch of DirecTV 7S," said Jean-Yves Le Gall, CEO of Arianespace. "In a few short months, we have worked together and accomplished our goal of providing unrivaled service and on-time launch to our customer."

The alliance competes with International Launch Services -- the joint U.S./Russian venture created a decade ago to globally market Atlas and Proton rockets. ILS offers a mutual backup option that allows satellites to switch between the two rocket families if delays occur.

1328 GMT (9:28 a.m. EDT)

T+plus 46 minutes. Ground controllers have acquired signals from the DirecTV 7S satellite via a German tracking station, confirming the spacecraft is alive following launch into space today.

In the coming days, the spacecraft will maneuver itself into geostationary orbit 36,000 kilometers above the equator where it can match Earth's rotation and appear parked above 119 degrees West longitude. It is expected to be checked out and ready for service in June.

Built by Space Systems/Loral in Palo Alto, California, the satellite will be operated by DirecTV to expand the number of local television channels available to subscribers across the U.S.

1312 GMT (9:12 a.m. EDT)

T+plus 30 minutes, 25 seconds. SPACECRAFT SEPARATION! The DirecTV 7S direct-to-home television broadcasting spacecraft has been released from the Block DM-SL upper stage to complete this 13th Sea Launch flight in five years.

Controllers expect to acquire the first signals from the newly-launched DirecTV satellite in about 20 minutes via a tracking station in Weilheim, Germany.

1307 GMT (9:07 a.m. EDT)

T+plus 25 minutes. Deployment of the spacecraft from the upper stage is about 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.

1301 GMT (9:01 a.m. EDT)

T+plus 19 minutes, 50 seconds. Shutdown of the Block DM-SL's 11D58M main engine has been announced. This completes the powered phase of today's launch. The stage will now coast for about 10 minutes before deploying the 12,063-pound DirecTV 7S satellite around T+plus 29 minutes, 21 seconds.

1257 GMT (8:57 a.m. EDT)

T+plus 15 minutes, 30 seconds. About four minutes remain in this upper stage firing.

1254 GMT (8:54 a.m. EDT)

T+plus 12 minutes. For previous Sea Launch missions, the Block DM-SL upper stage performed one firing immediately after separation from the second stage to reach a low-altitude parking orbit, followed by a long coast period before re-igniting to reach geosynchronous transfer orbit.

For today's mission, however, the upper stage is conducting one, albeit longer, burn to reach the intended injection orbit for DirecTV 7S. Sea Launch says this is being done to optimize the rocket's performance during launch of this heavy satellite.

1251 GMT (8:51 a.m. EDT)

T+plus 9 minutes, 8 seconds. The Block DM-SL upper stage has ignited for an 11-minute firing to propel the DirecTV into geosynchronous transfer orbit.

1250 GMT (8:50 a.m. EDT)

T+plus 9 minutes. The second stage vernier engines have shut down and the spent stage has been jettisoned. It will impact the Pacific about 4,800 km downrange from the launch platform.

1249 GMT (8:49 a.m. EDT)

T+plus 7 minutes, 30 seconds. The second stage RD-120 main engine has shut down. The vernier engines continue to fire.

1249 GMT (8:49 a.m. EDT)

T+plus 7 minutes, 15 seconds. The second stage is throttling down in preparation for engine cutoff.

1249 GMT (8:49 a.m. EDT)

T+plus 7 minutes. Main engine and vernier steering thruster pressures on the second stage are reported normal.

1248 GMT (8:48 a.m. EDT)

T+plus 6 minutes. "Flight is nominal" is the report from mission control at the 6-minute mark.

1247 GMT (8:47 a.m. EDT)

T+plus 5 minutes, 30 seconds. The vehicle remains stable as the second stage continues to fire.

1245 GMT (8:45 a.m. EDT)

T+plus 3 minutes, 45 seconds. The command has been issued to jettison the rocket's payload fairing, or nose cone. It protected the satellite cargo during atmospheric ascent. The nose cone will impact the Pacific about 963 km downrange.

1245 GMT (8:45 a.m. EDT)

T+plus 3 minutes, 30 seconds. A good engine pressures are being reported on the second stage.

1244 GMT (8:44 a.m. EDT)

T+plus 2 minutes, 45 seconds. The first stage RD-171 engine has shut down and the spent stage was jettisoned. It will impact the Pacific Ocean approximately 831 km downrange from the Odyssey launch platform.

And the second stage engine has been ignited for its firing.

1244 GMT (8:44 a.m. EDT)

T+plus 2 minutes, 15 seconds. Coming up on staging. First stage engine performance is reported normal.

1243 GMT (8:43 a.m. EDT)

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

1242 GMT (8:42 a.m. EDT)

T+plus 30 seconds. The rocket is stable as it maneuvers to the proper heading to fly eastward along the equator.

1242 GMT (8:42 a.m. EDT)

LIFTOFF! Liftoff of the Sea Launch Zenit 3SL rocket carrying the DirecTV 7S spacecraft to expand local television coverage to subscribers across America.

1241 GMT (8:41 a.m. EDT)

T-minus 30 seconds. The final readiness checks have been completed to verify all systems are "go" for an on-time launch. Stand by for terminal count.

1241 GMT (8:41 a.m. EDT)

T-minus 1 minute and counting. Final approval is being given for liftoff.

1240 GMT (8:40 a.m. EDT)

T-minus 2 minutes and counting. The engine start preparations are beginning to ready the first stage RD-171 powerplant for ignition. The Russian-made engine has four nozzles and powers the rocket for the first two-and-a-half minutes of flight.

1239 GMT (8:39 a.m. EDT)

T-minus 3 minutes and counting. The arm has been returned to the hangar.

1237 GMT (8:37 a.m. EDT)

T-minus 5 minutes and counting. All remains set for liftoff at 1242 GMT.

1230 GMT (8:30 a.m. EDT)

T-minus 12 minutes and counting. The launch site weather conditions at the equator are acceptable for this morning's flight. Winds are 9 knots from east and the temperature is 80 degrees F.

1226 GMT (8:26 a.m. EDT)

T-minus 16 minutes. The transporter/erector arm is starting to retract 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. Once the arm is lowered to the platform deck, 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.

1222 GMT (8:22 a.m. EDT)

T-minus 20 minutes. Sea Launch is not reporting any problems at this time.

1210 GMT (8:10 a.m. EDT)

Weather conditions are favorable and the countdown is entering the final minutes for today's launch of the Zenit 3SL rocket with DirecTV 7S.

Liftoff time is 1242 GMT. That is 20 minutes after the opening of the day's available two-hour launch window. Instead of targeting the beginning of the window, Sea Launch officials picked 1242 GMT to accommodate availability of NASA's Tracking and Data Relay Satellite System, which is used capture data from the rocket during ascent.

SUNDAY, MAY 2, 2004

The Sea Launch fleet has arrived on station in the mid-Pacific Ocean in advance of its second mission of the year -- deployment of the DirecTV 7S broadcast satellite early Tuesday morning.

Liftoff of the Sea Launch Zenit 3SL rocket with a direct-to-home broadcast satellite aboard is set for 1242 GMT (8:42 a.m. EDT) Tuesday, or in the wee hours of the morning at the Odyssey launch platform anchored along the Equator south of Hawaii. The day's two-hour launch window opens at 1222 GMT.

The Odyssey platform and the Sea Launch Commander control ship both reached the launch site on Thursday after a journey of over a week from the Sea Launch home port in Long Beach, California.

Odyssey was soon ballasted to a depth of 65 feet to keep the vessel stable during launch operations, and final preparations were made throughout the weekend aboard both ships. The 72-hour countdown sequence was begun early Saturday.

The Zenit booster was to be rolled out of its protective hangar aboard Odyssey and onto its launch pedestal early Monday.

The 13th Sea Launch flight will deliver the 12,063-pound DirecTV 7S satellite into a highly elliptical geostationary transfer orbit about a half-hour after liftoff. It will then begin a series of orbit-raising maneuvers to gradually settle into its permanent position 22,300 miles high above the Pacific Ocean along the Equator at 119 degrees West longitude.

Once in its final parking spot, the Loral-built DirecTV 7S will go into service featuring the company's second spot beam in space, which offers highly localized broadcasting options to DirecTV's 12.2 million customers. An additional 41 markets will be served with local channel capabilities, expanding the total number of DirecTV local markets to 106.

Work leading up to this mission began soon after the Sea Launch vessels returned from their previous flight in January. The DirecTV 7S payload was transported to Long Beach on March 9, and spacecraft activities including fueling and final tests were conducted in the following weeks.

DirecTV 7S was rolled out of the processing facility to the Sea Launch Commander on April 9 for attachment to the Zenit 3SL rocket, and the complete launch vehicle was transferred to Odyssey on April 15. The booster was erected the next day for final checks.

Odyssey left Long Beach en route to the Equator on April 18, followed three days later by the departure of the much faster Sea Launch Commander. The two met up in the expanse of the Pacific on April 26 to continue the rest of the voyage together.

Looking ahead to the launch day activities, fueling of the rocket with its highly refined kerosene and liquid oxygen propellant begins in the hours leading up to blastoff. The erector arm will be retracted and lowered away from the vehicle about 17 minutes before launch.

After liftoff, the first stage's RD-171 engine will burn for 2 minutes, 29 seconds before shutting down and separating. The nose cone shielding the payload will be jettisoned about a minute later. The second stage will continue firing until about 8 minutes, 41 seconds into flight, followed by stage separation and ignition of the Block DM-SL upper stage for its almost 11-minute burn to place the spacecraft into its intended orbit. Spacecraft separation is slated for 29 minutes, 21 seconds after liftoff.

Stay with Spaceflight Now for updates during the launch.