BY SPACEFLIGHT NOW

Follow the preparations and launch of the Intelsat 904 communications satellite aboard an Arianespace Ariane 4 rocket. Reload this page for the very latest on the mission.

SATURDAY, FEBRUARY 23, 2002

Arianespace has released the orbit data from this morning's launch, which indicates the Intelsat 904 satellite was delivered into the proper orbit.

The geosynchronous transfer orbit has a high point of 35,947 km for a target of 35,944 km, a low point of 200.1 km for a target of 199.8 km and inclination of 6.99 degrees for a target of 7.00 degrees.

0735 GMT (2:35 a.m. EST)

The deployment of Intelsat's latest generation of telecommunications satellites continued this morning with the successful launch of the Intelsat 904 spacecraft aboard an Ariane 4 rocket.

Running three days late by rocket troubles, liftoff from the Guiana Space Center on the northeast coast of South America occurred at the opening of today's window at 0659 GMT (1:59 a.m. EST).

Some 21 minutes later, the rocket's third stage released Intelsat 904 into an egg-shaped geosynchronous transfer orbit, marking the 67th straight success for the Ariane 4 vehicle dating back to 1995.

"Thank you very much," Terry Edwards, Intelsat Satellite Mission Director, said after the satellite separated from the Ariane 4. "Successful launches are not random events but the result of a lot of hard work by dedicated professionals."

Ground controllers expect to establish contact with Intelsat 904 via a tracking station in Perth, Australia, in the next few minutes. In the coming days the craft will perform a series of maneuvers to achieve a final geostationary orbit 36,000 km above the equator where it will be parked at 60 degrees East longitude.

When the satellite enters service in early April, Intelsat 904 will provide increased communications capacity at higher power for Intelsat's customers in Europe, Africa, Asia and Australia. The craft is designed to support enhanced C-band coverage for the Indian Ocean Region and high-power Ku-band spot beam coverage for Europe and the Middle East, relaying TV broadcasts, data transmissions and high-speed Internet applications.

Intelsat 904 will replace the 12-year-old Intelsat 604 spacecraft, launched in June 1990 aboard a commercial Titan 3 rocket from Cape Canaveral, Florida. The 604 satellite will be moved to 157 degrees East over the Pacific for inclined orbit operations.

Built by Space Systems/Loral, the Intelsat 904 is actually the third of seven new satellites of the Intelsat 9-series to be launched. The Intelsat 903 craft is being prepared for liftoff from Russia on a Proton rocket.

Today marked the 66th launch of an Intelsat satellite and 20th time an Ariane rocket has been used.

The next Arianespace launch is the highly-anticipated return of Ariane 5 after its failure last July. Liftoff is scheduled for Thursday evening carrying the European Space Agency's mammoth Envisat environmental research satellite.

0720 GMT (2:20 a.m. EST)

Plus+21 minutes. SPACECRAFT SEPARATION! The Intelsat 904 telecommunications satellite has been released into space from the Ariane 4 rocket's third stage, completing this morning's launch of Arianespace Flight 148.

0719 GMT (2:19 a.m. EST)

Plus+20 minutes. The third stage is performing its planned maneuvers. One minute from payload separation.

0718 GMT (2:18 a.m. EST)

Plus+19 minutes, 30 seconds. Altitude is 282 km, velocity 9.69 km/sec.

0718 GMT (2:18 a.m. EST)

Plus+19 minutes. Confirmation of third stage shut down, completing the powered phase of flight. Orbit has been achieved. The stage will now provide the necessary pointing for deployment of the Intelsat 904 spacecraft over the next two minutes. Altitude is 256 km, velocity 9.7 km/sec.

0717 GMT (2:17 a.m. EST)

Plus+18 minutes. Standing by for cutoff of the third stage in less than a minute. The Libreville tracking station in Africa has acquired the rocket's signal. Altitude is 214 km, velocity 9.31 km/sec.

0716 GMT (2:16 a.m. EST)

Plus+17 minutes, 30 seconds. Altitude is 202.1 km, velocity 9.0 km/sec.

0715 GMT (2:15 a.m. EST)

Plus+16 minutes, 30 seconds. The rocket has bottomed out in its sling-shot to orbit and is now climbing higher. Vehicle parameters and trajectory reported normal. The altitude is 189 km, velocity 8.62 km/sec.

0714 GMT (2:14 a.m. EST)

Plus+15 minutes, 50 seconds. About three minutes left in the third stage burn. Altitude is 187.1 km, velocity 8.32 km/sec.

0713 GMT (2:13 a.m. EST)

Plus+14 minutes, 15 seconds. The Ariane rocket continues to gain speed. Altitude is 195 km, velocity 7.7 km/sec.

0711 GMT (2:11 a.m. EST)

Plus+12 minutes, 30 seconds. The Ascension Island tracking station in the Atlantic Ocean has acquired the rocket's signal as it heads eastward away from South America. Altitude is 215 km, velocity 7.1 km/sec.

0710 GMT (2:10 a.m. EST)

Plus+11 minutes, 30 seconds. This is now the period in flight where the Ariane rocket gives up a bit of altitude in order to gain velocity like a sling-shot. Altitude is 226 km, velocity 6.77 km/sec.

0709 GMT (2:09 a.m. EST)

Plus+10 minutes. Altitude 234.7 km, velocity 6.35 km/sec.

0707 GMT (2:07 a.m. EST)

Plus+8 minutes, 50 seconds. Third stage burn continues. Altitude 232 km, velocity 6.00 km/sec.

0706 GMT (2:06 a.m. EST)

Plus+7 minutes. The Natal tracking station in Brazil has picked up the rocket's signal as it travels downrange. Vehicle remains on the proper course with system performance reported normal. Altitude is 205 km, velocity 5.6 km/sec.

0705 GMT (2:05 a.m. EST)

Plus+6 minutes. Burnout of the second stage has occurred and the spent stage has jettisoned. The cryogenic upper stage has now ignited for its long-duration burn to deliver the Intelsat 904 satellite payload into orbit.

0704 GMT (2:04 a.m. EST)

Plus+5 minutes, 30 seconds. Second stage continues to burn. Altitude is 159 km, velocity 5.30 km/sec.

0703 GMT (2:03 a.m. EST)

Plus+4 minutes, 30 seconds. The payload fairing has been jettisoned since it is no longer needed to shield the Intelsat 904 spacecraft. Altitude is 124 km, velocity 3.8 km/sec.

0702 GMT (2:02 a.m. EST)

Plus+3 minutes, 40 seconds. The four first stage main engines have shut down and the spent stage was jettisoned. And the second stage has now ignited.

0702 GMT (2:02 a.m. EST)

Plus+3 minutes. Altitude is 62.7 km, velocity 2.2 km/sec.

0701 GMT (2:01 a.m. EST)

Plus+2 minutes, 34 seconds. The four liquid-propellant strap-on boosters have shut down and separated from the Ariane 4's first stage. The spent casings fall into the Atlantic Ocean. The first stage main engines are still burning to continue the climb to orbit.

0701 GMT (2:01 a.m. EST)

Plus+2 minutes. Altitude 24 km, velocity 0.9 km/sec.

0700 GMT (2:00 a.m. EST)

Plus+90 seconds. So far so good in this flight of the Ariane 4 rocket. Altitude 12 km, velocity 0.4 km/sec. Trajectory reported normal. All engines continue to fire as the vehicle streaking into the predawn sky.

0700 GMT (2:00 a.m. EST)

Plus+60 seconds. Altitude 4.1 km, velocity 0.2 km/sec.

0659 GMT (1:59 a.m. EST)

Plus+30 seconds. Ariane has pitched to the proper eastward trajectory away from the launch site. The rocket is riding the thrust of eight engines -- four main engines and four liquid-fueled strap-on boosters.

0659 GMT (1:59 a.m. EST)

LIFTOFF! Liftoff of the Ariane 4 rocket and the Intelsat 904 communications spacecraft -- the 20th Intelsat satellite to ride an Arianespace rocket. And the vehicle has cleared the tower!

0653 GMT (1:53 a.m. EST)

Minus-6 minutes. The synchronized launch sequence has started. Computers are now in control of this final segment of the launch countdown.

During the next six minutes, the Ariane 44L rocket, satellite payload and ground systems will be configured for launch. There are two master computers running the countdown. One is responsible for fluids and propellants and the other for final preparation of the electrical systems such as initiating the flight program, activation of the engine steering systems and power transfer from ground supplies to onboard batteries. The computers will control until minus 5 seconds when a majority logic sequencer takes over for first stage and liquid-booster engine start at zero seconds. Engine performance checks are done in parallel by the two computers starting at plus 2.8 seconds. Finally, the command will be issued to open the launch table clamps for liftoff between ignition +plus 4.1 and 4.6 seconds.

0639 GMT (1:39 a.m. EST)

Minus-20 minutes and counting down to this morning's launch of the Ariane 44L rocket with the Intelsat 904 communications satellite. The three-stage rocket has been fully fueled and prepared for liftoff at 0659 GMT from the ELA-2 pad at the Guiana Space Center in Kourou, French Guiana on South America's northeast coastline.

Launch team members are watching systems on the Ariane 4 rocket, the spacecraft and ground support equipment. There are no problems being reported at this time.

The Ariane 44L rocket stands 56.3 meters tall and weighs 486 metric tons at liftoff. The Intelsat 904 spacecraft accounts for 4,722 kg (10,388 pounds) of that weight, making the cargo one of Ariane 4's heaviest payloads.

Today's launch will be the second Arianespace flight in 2002 and the 147th in the entire Ariane program. It will be the 109th Ariane 4 mission and the 34th for the Ariane 44L version with four liquid strap-on rocket boosters.

We'll update next once the countdown switches to computer control at Minus 6 minutes, or sooner if necessary.

0420 GMT (11:20 p.m. EST Fri.)

The final hours of the countdown are ticking away at the Guiana Space Center for today's launch of Arianespace Flight 148 -- an Ariane 44L rocket with Intelsat 904. Liftoff is scheduled for 0659 GMT (1:59 a.m. EST), the opening of a 60-minute window.

Watch this page for periodic updates on the countdown and flight starting about 20 minutes before liftoff time when Arianespace starts providing updates from the launch site.

FRIDAY, FEBRUARY 22, 2002

Arianespace says its Ariane 4 rocket is ready for launch in the predawn hours of Saturday to deliver the Intelsat 904 communications satellite into orbit. Liftoff had been scheduled for Tuesday, but was delayed last week. The launch company withheld any word of the delay until about 12 hours before the expected liftoff time.

TUESDAY, FEBRUARY 19, 2002
1900 GMT (2:00 p.m. EST)

Launch of the Ariane 4 rocket and Intelsat 904 spacecraft has been postponed three days due to technical troubles with the vehicle, Arianespace announced this afternoon, just 12 hours before the advertised liftoff time!

The European launch firm had not disclosed any problems with the pre-flight campaign until a short time ago. In reality, activities have been running behind schedule since last week and the satellite was not delivered to the launch pad and attached to the rocket until yesterday!

"The shift in timing followed additional work on the fairing, which protects the mission's Intelsat 904 satellite payload during climb-out through the atmosphere," Arianespace said in a statement.

As of Monday, an Arianespace spokesperson said everything was proceeding on schedule for tonight's countdown and launch.

Liftoff is now scheduled for 0659 GMT (1:59 a.m. EST) on Saturday.

TUESDAY, FEBRUARY 19, 2002

Work in the South American jungle is in the final stages as Arianespace gears up for Wednesday's predawn launch of an Ariane 4 rocket carrying an international telecommunications satellite for operator Intelsat.

The Ariane 44L is poised to ignite and head to space at 0659 GMT (1:59 a.m. EST) from the ELA-2 launch complex at Kourou, French Guiana.

The Intelsat 904 communications craft will be placed into orbit by the Ariane 44L rocket, which features four liquid-fueled boosters. The satellite will then guide itself into a circular geostationary orbit, where it will appear to "hover" 24 hours a day at a point over the equator at 60 degrees East, or 22,300 miles above the Indian Ocean.

From that orbital perch, Intelsat 904 will use its C-band and Ku-band transponders and other associated equipment to provide Internet, broadcast, telephony and corporate network services to users across a wide area that includes Europe, Central Asia, the Far East, and Australia. The Space Systems/Loral-built spacecraft is designed to operate for at least 13 years.

Intelsat 904 will weigh 10,296 pounds during Wednesday's morning launch, with almost half of that number being represented by propellants and other fluids. The craft's power-producing solar arrays will stretch almost 100 feet tip-to-tip once fully deployed.

This satellite is the third in the Intelsat 9 series to launch so far, with both Intelsat 901 and 902 having been hauled into space aboard Ariane 4 rockets in mid-2001. Intelsat 903 is currently scheduled to be lofted into orbit next month atop a Russian Proton rocket marketed by International Launch Services.

Preparations for Flight 148 began on January 7 when the Intelsat 904 spacecraft arrived in Kourou for launch.

The launcher began to take shape when the rocket's first stage was lifted and placed into position on the mobile launch table inside the launcher integration building on January 11. This action was followed by the stacking of the second and third stages on January 17 and 18, respectively.

The Ariane 44L's four liquid-fueled strap-on boosters were attached around the base of the first stage one-at-a-time from January 14-18.

Fueling of Intelsat 4 with its highly toxic propellants began on February 5, followed the next day by the rollout of the nearly-complete Ariane 4 from the integration building to the ELA-2 launch zone.

Looking ahead to the events leading up to launch on Tuesday and Wednesday, the final countdown will commence at 1829 GMT (1:29 p.m. EST). The protective mobile service gantry will begin pulling away from the launch pad at 0124 GMT Wednesday (8:24 p.m. EST Tuesday). Cryogenic liquid hydrogen and liquid oxygen will be pumped into the launcher's third stage starting at 0324 GMT (10:24 p.m. EST). At 0554 GMT (12:54 a.m. EST Wednesday), the rocket's telemetry, telecommand, and radar transponder systems will be activated. The countdown will enter the so-called synchronized launch sequence six minutes prior to liftoff. Following that crucial point are a series of fast-paced events that will culminate with the ignition of the first stage and four boosters at T-0. Liftoff will occur four seconds later.

The Ariane 44L will then take a normal ascent profile that includes a 2-minute, 30-second burn of the rocket's four liquid-fueled boosters. The first stage will burn for another minute before cutting off and separating 3 minutes, 31 seconds into flight. The second stage will then take over propulsion and burn for two minutes, during which time the launcher's payload fairing will be jettisoned. After stage two finishes its job, the third stage will then come to life and fire for a marathon 13-minute burn before shutting down to end the powered phase of flight. Spacecraft separation is expected just under 21 minutes after liftoff.

Flight 148 marks the 147th flight of an Ariane rocket, the 109th launch of the Ariane 4 family, and the 20th launch of an Intelsat craft aboard an Ariane. After Wednesday morning's flight, only seven Ariane 4's will remain to be launched before the family is retired in favor of the next-generation Ariane 5 launcher.

Stay with Spaceflight Now for updates on the countdown and launch early Wednesday.