BY SPACEFLIGHT NOW

Follow the preparations and launch of the Intelsat 902 communications satellite aboard an Arianespace Ariane 4 rocket. Reload this page for the very latest on the mission.

THURSDAY, AUGUST 30, 2001

Intelsat took another step forward today to increase the capacity of its global telecommunications satellite network with the successful launch of the high-powered Intelsat 902 spacecraft aboard an Ariane 4 rocket.

Liftoff occurred right on time at 0646 GMT (2:46 a.m. EDT) as the Arianespace launcher gracefully climbed off its pad in Kourou, French Guiana, beginning a 21-minute flight to place its 10,410-pound cargo into an egg-shaped geosynchronous transfer orbit.

No problems were reported during the flight and Intelsat 902 separated from the rocket's third stage as scheduled to complete the 63rd consecutive successful launch of the Ariane 4.

"Bravo and congratulations to all the teams who once again made this success possible," Jean-Marie Luton, Arianespace's president and CEO, said in a post-launch speech.

Data indicates the rocket delivered Intelsat 902 into a good orbit with an apogee of 35,924 km, perigee of 199.8 km and inclination of 7.00 degrees.

Four firings of the satellite's onboard engine are planned to boost the craft into a circular geostationary orbit 36,000 km above the Equator. Intelsat 902 will be parked at 62 degrees East over the Indian Ocean where it will cover Europe, the Middle East, sub-Saharan Africa, Central Asia, the Far East and Australia to relay television and data transmissions and provide Internet connection and telephone services.

Built by Space Systems/Loral, the Intelsat 902 is the second of seven new satellites of the Intelsat 9-series that will be launched over the next two years, replacing older, less capable spacecraft in the consortium's fleet.

Intelsat 902 should become operational around October 28, taking over for the aging Intelsat 602 satellite that will be repositioned to 33 degrees East in an inclined orbit.

Today marked the 19th time an Intelsat spacecraft was launched by an Ariane rocket dating back to 1983. Intelsat has become Arianespace's leading customer.

"Our competent Arianespace friends from Europe have once again delivered an Intelsat satellite into orbit, and we thank you," Conny Kullman, Intelsat's director general and chief executive officer, said after the launch.

Launch of Intelsat 903 is scheduled for November aboard a commercial ILS Proton K rocket with a Block DM upper stage from the Baikonur Cosmodrome in Kazakhstan. The remaining four Intelsat 9 satellites will be carried aloft by Ariane 4 rockets in 2002.

The next Arianespace launch is scheduled for September 25 when Eutelsat's Atlantic Bird 2 communications satellite will ride an Ariane 4 to orbit. The spacecraft was scheduled to launch on the next Ariane 5, but that rocket is grounded due to an upper stage failure in July. So Arianespace shifted the craft to an Ariane 4 in order to launch as soon as possible.

The Arianespace backlog now stands at 42 satellites to be launched, plus nine cargo resupply missions for the International Space Station.

0715 GMT (3:15 a.m. EDT)

Arianespace has proclaimed success for today's launch of Intelsat 902. This marks the 63rd straight success for the Ariane 4 rocket dating back to 1995.

0706 GMT (3:06 a.m. EDT)

Plus+20 minutes, 55 seconds. SPACECRAFT SEPARATION! The Intelsat 902 telecommunications satellite has been released into space from the Ariane 4 rocket's third stage, completing this morning's launch of Arianespace Flight 143.

We'll have a full wrap-up story a bit later today.

0706 GMT (3:06 a.m. EDT)

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

0705 GMT (3:05 a.m. EDT)

Plus+19 minutes, 30 seconds. Altitude is 295 km, velocity 9.68 km/sec.

0704 GMT (3:04 a.m. EDT)

Plus+18 minutes, 50 seconds. 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 902 spacecraft over the next two minutes.

0704 GMT (3:04 a.m. EDT)

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 221 km, velocity 9.39 km/sec.

0702 GMT (3:02 a.m. EDT)

Plus+16 minutes, 30 seconds. The rocket has bottomed out in its sling-shot to orbit and is now climbing higher. The altitude is 190 km, velocity 8.7 km/sec.

0701 GMT (3:01 a.m. EDT)

Plus+15 minutes, 50 seconds. About three minutes left in the third stage burn. Vehicle parameters and trajectory reported normal. Altitude is 187 km, velocity 8.45 km/sec.

0700 GMT (3:00 a.m. EDT)

Plus+14 minutes, 10 seconds. The Ariane rocket continues to gain speed. Altitude is 193 km, velocity 7.73 km/sec.

0658 GMT (2:58 a.m. EDT)

Plus+12 minutes, 50 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 207 km, velocity 7.27 km/sec.

0657 GMT (2:57 a.m. EDT)

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 222 km, velocity 6.8 km/sec.

0656 GMT (2:56 a.m. EDT)

Plus+10 minutes. Altitude 230 km, velocity 6.39 km/sec.

0654 GMT (2:54 a.m. EDT)

Plus+8 minutes, 30 seconds. Third stage burn still on going with no problems reported. Trajectory and vehicle parameters are normal. Altitude 225 km, velocity 6.01 km/sec.

0653 GMT (2:53 a.m. EDT)

Plus+7 minutes, 10 seconds. The Natal tracking station in Brazil has picked up the rocket's signal as it travels downrange. Vehicle remains on the proper course. Altitude is 207 km, velocity 5.74 km/sec.

0652 GMT (2:52 a.m. EDT)

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 902 satellite payload into orbit.

0651 GMT (2:51 a.m. EDT)

Plus+5 minutes, 30 seconds. Second stage continues to burn normally. No problems reported so far. Altitude is 156 km, velocity 5.39 km/sec.

0650 GMT (2:50 a.m. EDT)

Plus+4 minutes, 30 seconds. The payload fairing has been jettisoned since it is no longer needed to shield the Intelsat 902 spacecraft. Altitude is 123 km, velocity 3.87 km/sec.

0649 GMT (2:49 a.m. EDT)

Plus+3 minutes, 40 seconds. The four first stage main engines have shut down and stage separation confirmed. A flash was seen by the powerful tracking cameras in the clear night sky.

And the second stage has now ignited.

0649 GMT (2:49 a.m. EDT)

Plus+3 minutes. Altitude is 62 km, velocity 2.24 km/sec.

0648 GMT (2:48 a.m. EDT)

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.

0647 GMT (2:47 a.m. EDT)

Plus+90 seconds. So far so good in this flight of the Ariane 4 rocket. Trajectory reported normal. All engines continue to fire as the vehicle streaking into the predawn sky.

0647 GMT (2:47 a.m. EDT)

Plus+60 seconds. All vehicle parameters reported normal.

0646 GMT (2:46 a.m. EDT)

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.

0646 GMT (2:46 a.m. EDT)

LIFTOFF! Liftoff of the Ariane 4 rocket with Intelsat 902 -- a new spacecraft to cover the Indian Ocean region for the International Telecommunications Satellite Organization. And the vehicle has cleared the tower!

0645 GMT (2:45 a.m. EDT)

Minus-30 seconds.

0645 GMT (2:45 a.m. EDT)

Minus-1 minute. Equipment aboard the Ariane 44L rocket is being switched off ground-supplied power and to onboard batteries for launch.

In the final seconds of the countdown, activities will include releasing the inertial platform at minus 9 seconds, and the release command to the retraction system for the two cryogenic arms will be given at Minus-5 seconds.

0644 GMT (2:44 a.m. EDT)

Minus-90 seconds and counting. The local tracking stations at the launch site should have a firm lock on the rocket at this time.

0644 GMT (2:44 a.m. EDT)

Minus-2 minutes and counting. The third stage liquid oxygen tank has been pressurized for the launch.

0643 GMT (2:43 a.m. EDT)

Minus-3 minutes and counting. Flight 143 will be the sixth Arianespace launch in 2001 and the 143rd in the entire Ariane program. It will be the 105th Ariane 4 mission and the 33rd for the Ariane 44L version with four liquid strap-on rocket boosters.

0642 GMT (2:42 a.m. EDT)

Minus-4 minutes and counting. The launch team is monitoring the final topping off of liquid oxygen and liquid hydrogen supplies aboard the rocket's third stage.

In the next half-minute, the launch time will be loaded aboard the Ariane rocket's guidance system. Also, the Intelsat 902 spacecraft will be confirmed on internal power and declared ready for launch.

0640 GMT (2:40 a.m. EDT)

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 (2:39 a.m. EDT)

Minus-7 minutes. The computer-run synchronized sequence to govern the final countdown to launch will start in one minute. Liftoff remains set to occur at 0646 GMT (2:46 a.m. EDT).

0636 GMT (2:36 a.m. EDT)

Minus-10 minutes and counting. A network of tracking stations are standing ready to relay data from the Ariane 4 rocket to engineers in Kourou. The early portion of flight will be monitored through the Kourou and Cayenne stations in French Guiana. About 6 minutes, 30 seconds into flight the Natal station in Brazil will pick up the rocket's signal as the third stage burn gets underway. At T+plus 12 minutes, 30 seconds the site on Ascension Island in the Atlantic Ocean will begin coverage. Libreville in Gabon will provide services beginning at T+plus 17 minutes, 30 seconds for spacecraft separation and the conclusion of Arianespace Flight 143.

0631 GMT (2:31 a.m. EDT)

Minus-15 minutes. The Ariane 44L rocket stands 56.3 meters tall and weighs 486 metric tons at liftoff. The Intelsat 902 spacecraft accounts for 4,723 kg (10,410 pounds) of that weight, making the cargo one of Ariane 4's heaviest payloads.

0626 GMT (2:26 a.m. EDT)

Minus-20 minutes and counting down to this morning's launch of the Ariane 44L rocket with the Intelsat 902 communications satellite -- the second in the new series of spacecraft for the International Telecommunications Satellite Organization.

The three-stage rocket has been fully fueled and prepared for liftoff at 0646 GMT from the ELA-2 pad at the Guiana Space Center in South America.

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 for this 6th Arianespace launch of 2001.

0616 GMT (2:16 a.m. EDT)

Minus-30 minutes and counting. The countdown is entering the final half-hour for the launch of Arianespace Flight 143. The status panel in the Jupiter control center is green across the board, indicating all systems are "go" at this time.

0605 GMT (2:05 a.m. EDT)

Good morning and welcome to our live coverage of the launch of Arianespace Flight 143. The Ariane 44L rocket is scheduled to lift off with the Intelsat 902 communications satellite at 0646 GMT (2:46 a.m. EDT) from Kourou, French Guiana in South America.

TUESDAY, AUGUST 28, 2001

Six weeks after its next-generation Ariane 5 rocket malfunctioned, Arianespace is ready for its next commercial satellite launch, albeit using the older workhorse Ariane 4 booster.

Officials have cleared the Ariane 4 for blastoff at 0646 GMT (2:46 a.m. EDT) Thursday from the ELA-2 launch complex at the Guiana Space Center in Kourou, French Guiana on South America's northeastern coast.

Investigators probing the July 12 failure of the Ariane 5 blamed the mishap on "combustion instability" during ignition of the rocket's upper stage. The pressure spike caused an inproper mixture of fuel and oxidizer feeing to the stage's engine, resulting in reduced thrust and a premature engine shutdown when the oxidizer was used up 80 seconds sooner than planned. The rocket's two satellite cargos were deployed into an orbit vastly lower than planned due to the upper stage trouble.

The seven-member panel did exonerate the Ariane 4 rocket's systems from the Ariane 5 failure, clearing the way for Arianespace to continue launches while engineers work to fix the Ariane 5 upper stage so it can return to flight by year's end.

Thursday's launch will use the Ariane 44L version of the venerable rocket, which includes four liquid-fueled strap-on boosters to augment the performance of the launcher during the early part of its flight.

Perched high atop the rocket is the Intelsat 902 telecommunications satellite. The 10,410-pound Intelsat 902 will be positioned in geostationary orbit 22,300 miles above the Indian Ocean at 62 degrees East to take part in Internet, broadcast, telephone and corporate network telecommunications operations.

Intelsat 902's C-band and Ku-band transponders will be able to reach users in Europe, sub-Saharan Africa, central Asia, the Far East, and Australia during the craft's projected 13-year lifetime.

Flight 143's payload was built by Space Systems/Loral of Palo Alto, California, and is based on their FS1300 Extended series of spacecraft buses. Once the satellite is in orbit, its fully deployed solar panels will extend over 90 feet tip-to-tip and will produce 8-1/2 kilowatts of electricity for the craft at the beginning of operations.

Preparations for Flight 143 began on July 17 with the arrival in Kourou of the mission's payload -- Intelsat 902. Activities involving the Ariane 4 launcher were kicked off on July 19 with the process of lifting the rocket's first stage into the vertical position on the mobile launch table.

One day later, the Ariane's second stage was lifted and placed on top of the first stage. The rocket's third and uppermost stage was erected on July 27.

Also, the Ariane 44L's four strap-on boosters were placed around the first stage starting on July 24 and ending on July 27.

The nearly-complete launcher for Flight 143 was rolled along dual rail tracks from the launcher integration building to the ELA-2 launch pad on August 9.

Meanwhile, the processing of Intelsat 902 took a major step forward on August 16 when fueling operations began.

The satellite payload was tucked inside the Ariane 4's protective payload fairing on August 21, followed the next day by the transfer of the entire payload unit -- including the payload, fairing, and associated equipment -- to the launch pad. The payload was attached to the launcher on August 23, finishing the assembly of the rocket.

Last Friday, a final "refresher" launch dress rehearsal was held, mimicking the activities during Wednesday and Thursday's countdown.

A launch readiness review took place on Monday, concluding with the official go-ahead for the countdown and launch. After hearing the word of the "go" decision, workers armed the launcher by hooking up pyrotechnics and other equipment.

On Tuesday, the rocket's first stage, second stage, and four liquid-fueled boosters were filled with their propellant load of unsymmetrical dimethyl hydrazine and nitrogen tetroxide.

Looking ahead to Wednesday and Thursday's final countdown and launch, the final countdown will commence at 1816 GMT (2:16 p.m. EDT). The ELA-2 mobile service gantry will begin retracting from around the launch pad at 0111 GMT (9:11 p.m. EDT). The third stage will be fueled with liquid hydrogen and liquid oxygen beginning at 0311 GMT (11:11 p.m. EDT). The activation of the launcher's telemetry, radar transponders, and telecommand systems will occur at 0541 GMT (1:41 a.m. EDT). At 0640 GMT (2:40 a.m. EDT), the synchronized launch sequence will begin. Following this very important milestone, a series of fast-paced events will occur that will lead up to the ignition of the Ariane 44L's first stage and four liquid-fueled strap-on boosters at T-0. Liftoff will occur 4.4 seconds later.

Flight 143 will take a normal Ariane 44L ascent profile with a two-minute, 30-second burn of the four boosters and a three-minute, 31-second burn of the first stage. Stage 2 will take over three minutes, 34 seconds after launch and will burn for around two minutes, during which time the protective payload fairing will be jettisoned. The third stage will ignite five minutes, 48 seconds after launch and will continue thrusting for around 13 minutes. Separation of the Intelsat 902 satellite is expected at a point almost 21 minutes into flight.

Stay with Spaceflight Now for complete coverage of the final countdown and launch of Flight 143 on a mission to deliver a high-power communications satellite into orbit.