Spaceflight Now: V129


April 19, 2000 -- Follow the launch of PanAmSat's Galaxy 4R communications satellite aboard an Ariane 4 rocket. Reload this page for the very latest on the mission.

0300 GMT (11:00 p.m. EDT)

Europe's Ariane 4 rocket placed a U.S. communications satellite into orbit Tuesday night but Arianespace's jungle launch pads will become silent until at least mid-summer due to spacecraft engine troubles.

Read our complete story for a full recap of the flight, Arianespace's future launch schedule and details on the Galaxy 4R spacecraft.

0130 GMT (9:30 p.m. EDT)

Hughes Space and Communications, builder of the Galaxy 4R satellite launched tonight, reports its ground control team has successfully established contact with the spacecraft through the Daan Magot tracking station in Indonesia. Initial checks of the satellite indicate Galaxy 4R is healthy.

We will have a full story about tonight's satellite-delivery mission, the near-term future of Arianespace's launch schedule and the upcoming events that will prepare Galaxy 4R for service.

0050 GMT (8:50 p.m. EDT)

Plus+21 minutes. SPACECRAFT SEPARATION! The Galaxy 4R communications satellite has successfully separated from the Ariane 4 rocket's third stage to complete Arianespace Flight 129. This marks the 54th consecutive success for Ariane 4.

Check back later tonight for a wrap-up story on this launch and confirmation first contact with Galaxy 4R by ground controllers.

0049 GMT (8:49 p.m. EDT)

Plus+20 minutes, 30 seconds. The orientation maneuvers to position the rocket to release Galaxy 4R has concluded. Altitude is 320 km, velocity is 9.5 km/sec.

0048 GMT (8:48 p.m. EDT)

Plus+19 minutes. Third stage has shut down to complete the powered flight. The stage will now provide the necessary pointing for deployment of Galaxy 4R in about two minutes.

0047 GMT (8:47 p.m. EDT)

Plus+18 minutes, 30 seconds. The Libreville tracking station in Africa has acquired the Ariane 4 rocket.

0047 GMT (8:47 p.m. EDT)

Plus+18 minutes. Less than one minute remaining in the third stage firing. Altitude is 204 km, velocity is 9.19 km/sec.

0046 GMT (8:46 p.m. EDT)

Plus+17 minutes, 15 seconds. The Ariane 4 rocket is now beginning to gain altitude again. Altitude is 195 km, velocity is 8.7 km/sec.

0045 GMT (8:45 p.m. EDT)

Plus+16 minutes, 30 seconds. Altitude is 194 km, velocity is 8.3 km/sec.

0044 GMT (8:44 p.m. EDT)

Plus+15 minutes. Altitude is 207 km, velocity is 7.6 km/sec.

0043 GMT (8:43 p.m. EDT)

Plus+14 minutes, 10 seconds. Just over 4 1/2 minutes left in the third stage burn tonight. Altitude is 220 km, velocity is 7.2 km/sec.

0041 GMT (8:41 p.m. EDT)

Plus+12 minutes, 30 seconds. The Ariane 4 rocket's third stage is still firing. Altitude is 247 km, velocity is 6.64 km/sec.

The Ascension Island tracking station in the Atlantic Ocean has acquired the rocket's signal as it heads eastward away from South America.

0040 GMT (8:40 p.m. EDT)

Plus+11 minutes, 30 seconds. Altitude is 259 km, velocity is 6.3 km/sec.

0039 GMT (8:39 p.m. EDT)

Plus+10 minutes, 40 seconds. Now reaching 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 266 km, velocity is 6.06 km/sec.

Also, the rocket is now passed out of range from the tracking station in Kourou.

0039 GMT (8:39 p.m. EDT)

Plus+10 minutes. A very smooth flight for the Ariane 4 rocket to this point. Altitude is 269 km, velocity is 5.8 km/sec.

0037 GMT (8:37 p.m. EDT)

Plus+8 minutes, 30 seconds. Rocket parameters and the trajectory are all reported normal at this point in the flight. Altitude is 261 km, velocity is 5.45 km/sec.

0036 GMT (8:36 p.m. EDT)

Plus+7 minutes, 30 seconds. Altitude is 245 km, velocity is 5.2 km/sec.

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

Plus+6 minutes, 30 seconds. The Natal tracking station in Brazil has picked up the rocket's signal. The Ariane 4 rocket is moving right down the proper trajectory tonight.

0034 GMT (8:34 p.m. EDT)

Plus+5 minutes, 35 seconds. Arianespace confirmed burnout of the second stage and its separation. The cryogenic upper stage has now ignited for its long-duration burn to deliver Galaxy 4R into orbit.

0034 GMT (8:34 p.m. EDT)

Plus+5 minutes. Altitude is 150 km, velocity is 4.3 km/sec.

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

Plus+4 minutes, 20 seconds. The protective payload fairing enclosing the Galaxy 4R spacecraft has been jettisoned from the rocket.

0032 GMT (8:32 p.m. EDT)

Plus+3 minutes, 25 seconds. The first stage has separated and ignition of the second stage has been confirmed. The Ariane 4 rocket continues its climb to orbit with Galaxy 4R.

0031 GMT (8:31 p.m. EDT)

Plus+2 minutes, 25 seconds. The twin strap-on liquid-propellant boosters have been jettisoned, which was seen in great tracking camera work tonight. No problems reported so far in the launch.

0030 GMT (8:30 p.m. EDT)

Plus+1 minute, 45 seconds. Altitude is 17 km, velocity is 0.65 km/sec.

0030 GMT (8:30 p.m. EDT)

Plus+1 minute. All vehicle systems working as planned, Arianespace says.

0029 GMT (8:29 p.m. EDT)

Plus+30 seconds. Ariane is in the pitch maneuver.

0029 GMT (8:29 p.m. EDT)

LIFTOFF! Liftoff of the Ariane 4 rocket with PanAmSat's Galaxy 4R spacecraft to bolster communications across North America. The vehicle has cleared the tower.

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

Minus 1 minute. Equipment aboard the Ariane 42L rocket is being switched 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.

0027 GMT (8:27 p.m. EDT)

Minus 2 minutes. This launch will be the 129th for an Ariane rocket, the fourth of 2000, the 96th Ariane 4 to be flown and the 11th for an Ariane 42L configuration vehicle with two liquid propellant strap-on boosters.

Galaxy 4R will be the 16th PanAmSat satellite launched aboard an Ariane 4 rocket, following PAS 1, 2, 3, 4, 6, 6B, 3R and 7, Galaxy 4, 6, 7, 11 and 10R and SBS 5 and 6.

In addition, Galaxy 4R will be the 37th Hughes Space and Communications-built satellite carried by Ariane and the 19th of which to be an HS601-model spacecraft.

0025 GMT (8:25 p.m. EDT)

Minus-3 minutes, 30 seconds. The launch time has been loaded aboard the Ariane rocket's guidance system. Also, the Galaxy 4R spacecraft is confirmed on internal power and declared ready for launch.

0025 GMT (8:25 p.m. EDT)

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

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

Minus-6 minutes. The synchronized launch sequence has started. Computers are now in control of this final segment of the launch countdown. Liftoff still targeted for 0029 GMT (8:29 p.m. EDT).

During the next six minutes, the Ariane 42L 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 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.

0021 GMT (8:21 p.m. EDT)

Minus-8 minutes and counting. Arianespace reports all systems are "go" across the board. Weather conditions are also acceptable for launch at 0029 GMT (8:29 p.m. EDT), a change from last week when record rainfall occurred last week in French Guiana.

The computer-run synchronized sequence to launch will start in two minutes.

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

Minus-10 minutes. The countdown continues smoothly. Liftoff remains set to occur at 0029 GMT (8:29 p.m. EDT).

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, 20 seconds into flight the Natal station in Brazil will pick up the rocket's signal as the third stage burn gets underway. At plus 12 minutes, 55 seconds the site on Ascension Island in the Atlantic Ocean will begin coverage. Libreville in Gabon will provide services for spacecraft separation and the conclusion of Arianespace Flight 129.

0014 GMT (8:14 p.m. EDT)

Minus-15 minutes and counting. Countdown clocks are ticking off the final minutes to tonight's launch of the Ariane 4 rocket carrying Galaxy 4R for operator PanAmSat and builder Hughes Space and Communications. There are no technical problems being reported and a final weather update will be given in about five minutes.

0004 GMT (8:04 p.m. EDT)

Minus-25 minutes and counting. The cargo to be launched into space tonight aboard the Ariane 4 rocket is PanAmSat's Galaxy 4R telecommunications satellite. It was built by Hughes Space and Communications Company to provide television, Internet and data transmission services to the Continental United States, Alaska, Hawaii and Puerto Rico.

Galaxy 4R currently weighs 8,069 pounds on the launch pad. It carries 24 C-band and 24 Ku-band transponders and will have 8,700 watts of power at the end of its 15-year life. The craft will be positioned at 99 degrees West longitude along the equator some 22,300 miles above the planet.

The spacecraft was shipped from the United States to Kourou on March 27. It underwent final testing and fueling before being encapsulation into the payload fairing. The craft was then transferred to the launch pad on April 12 and mated to the Ariane the following day.

Read about Galaxy 4R's planned uses and about the HS601 HP satellite from Hughes.

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

Minus-29 minutes. Arianespace says activities are proceeding smoothly for tonight's liftoff at 0029 GMT (8:29 p.m. EDT), the opening of a 70-minute launch window. There are no problems to report.

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

Minus-47 minutes and counting. The Ariane 42L rocket is fully fueled and poised for launch from the ELA-2 complex in Kourou, French Guiana along South America's northeast coast. The status board in the Jupiter control center is showing all "go" conditions. Liftoff remains scheduled for 0029 GMT (8:29 p.m. EDT).

The campaign for tonight's launch began on March 14 when the rocket's first stage was erected on the mobile table. The second stage was added the following day. The twin liquid-propellant boosters were attached on March 20 and 21 to the first stage's exterior. Finally, the third stage was mated on March 22. Rollout from the assembly building to the launch pad occurred on April 3. A launch countdown rehearsal was held on April 7.

The combined operations between the Ariane 4 rocket and Galaxy 4R spacecraft started on April 10. The next day the satellite was encapsulated within the rocket's awaiting nose cone inside a processing building at Kourou. The enclosed satellite was then taken to the launch pad on April 12 and hoisted atop the Ariane the following day.

Last Friday the launch rehearsal was completed. Officials gathered in Kourou on Saturday for the Launch Readiness Review, clearing the Ariane 4, Galaxy 4R satellite and ground systems for the mission. Also Saturday, the rocket was armed. On Monday the rocket's first and second stages and liquid-propellant strap-on boosters were loaded with storable fuels.

2140 GMT (5:40 p.m. EDT)

The sun is setting on the Ariane 4 rocket's jungle launch site as the final three hours of the countdown tick off. There are clouds around the Guiana Space Center but Arianespace hopes conditions will be acceptable for liftoff. At the ELA-2 launch pad, the mobile service gantry has been retracted and the rocket's third stage is being fueled with super-cold liquid hydrogen and liquid oxygen cryogenics.

Tonight's launch window opens at 0029 GMT (8:29 p.m. EDT) and extends to 0139 GMT (9:39 p.m. EDT).

We will provide complete coverage on this page tonight during the final half-hour of the countdown and 21-minute launch.

1745 GMT (1:45 p.m. EDT)

Arianespace reports its 96th Ariane 4 rocket remains on track for launch tonight from the Guiana Space Center in Kourou, French Guiana, South America. Liftoff will be possible during a window extending from 0029-0139 GMT (8:29 to 9:39 p.m. EDT).

The three-stage rocket will place PanAmSat's Galaxy 4R communications satellite into Earth orbit for this 129th flight by Arianespace.

MONDAY, APRIL 17, 2000
2200 GMT (6:00 p.m. EDT)

A European Ariane 4 rocket stands ready atop its South American launch pad for Tuesday evening's fiery climb to space to deliver a U.S. telecommunications broadcasting satellite into Earth orbit.

Launch officials at Arianespace report activities are proceeding smoothly for the scheduled liftoff at 0029 GMT (8:29 p.m. EDT), the opening of a 70-minute window in which to get the rocket off the ground.

Arianespace Mission Director Didier Casse says heavy rains experienced in Kourou recently have now stopped, and the forecast is calling for acceptable weather conditions at liftoff time.

Packaged inside the Ariane 4 rocket's nose cone is Galaxy 4R -- a high powered spacecraft that will beam television, radio and other telecommunications programming throughout North America. Users of the satellite will include the Encore movie channel, National Public Radio, Japan's NHK and AT&T's "Headend in the Sky" digital cable service designed to deliver more than 140 channels to cable systems in the U.S. In addition, Galaxy 4R will be used to deliver AOL Plus via DirecPC directly to customers. This high-speed relay of AOL's broadband content should be available to subscribers later this year.

The satellite was built by Hughes Space and Communications in El Segundo, California, for PanAmSat Corp. of Greenwich, Connecticut. Galaxy 4R is a replacement craft ordered after its namesake spun out of control and failed in space two years ago because of an onboard malfunction. The incident wiped out communications and pager services throughout the U.S. for a time.

Galaxy 4R's launch will complete PanAmSat's satellite expansion and redeployment plan for North America, enabling the migrations of the company's older Galaxy 6 and Galaxy 7 and new Galaxy 11 satellites to different orbital locations. Galaxy 4R will be PanAmSat's third satellite aimed at North America to be launched in less than four months, joining Galaxy 11 last December and Galaxy 10R in January.

"The upcoming launch of Galaxy 4R demonstrates PanAmSat's rapid deployment plans for new satellites, building upon the strength of our North American fleet and providing our customers with the most comprehensive and reliable services," said Robert Bednarek, PanAmSat's executive vice president and chief technology officer. "Galaxy 4R will deliver the highest-quality digital and analog video distribution, Internet and telecommunications services throughout the continent."

Back at the launch site in Kourou, French Guiana, located along South America's northeast coastline, workers Monday fueled the Ariane 4's first and second stages and twin strap-on boosters with storable propellants.

The final countdown to launch of Arianespace Flight 129 will start at 0959 GMT (5:59 a.m. EDT) on Tuesday. The 321-foot tall gantry enclosing the rocket at the ELA-2 launch complex will be retracted beginning at 1834 GMT (2:34 p.m. EDT). Loading of super-cold liquid oxygen and liquid hydrogen into the Ariane's third stage will commence at 2054 GMT (4:54 p.m. EDT). The launch team will activate the rocket's telemetry, radar transponders and telecommand systems just over an hour before launch at 2324 GMT (7:24 p.m. EDT). If there are no problems standing in the way of an on-time liftoff, officials will allow the Synchronized Launch Sequence to begin at Launch Minus-6 minutes. This computer-controlled process performs the final tasks to prepare the rocket for liftoff.

It is expected to take the Ariane rocket just under 21 minutes to carry Galaxy 4R into the intended highly elliptical geosynchronous transfer orbit around Earth. The satellite will later perform orbit raising maneuvers using its onboard kick motor, achieving a circular geostationary orbit around the Earth's equator. Controllers plan to park the satellite at 99 degrees West longitude.

PanAmSat currently has 20 spacecraft in orbit today and plans to expand its constellation to 24 satellites by mid-2001.

V129 launch Ariane V129 lifts off from its Kourou launch pad as seen in this Arianespace TV picture.

Flight data file
Vehicle: Ariane 42L
Payload: Galaxy 4R
Launch date: April 19, 2000
Launch window: 0029-0139 (8:29-9:39 p.m. EDT on 18th)
Launch site: ELA-2, Kourou, French Guiana

Pre-launch Briefing
Launch timeline - Chart with times and descriptions of the events to occur during launch.

Ariane 42L - Overview of the rocket to launch Galaxy 4R.

Purpose of Galaxy 4R - PanAmSat to enhance telecoomunications services to North America.

The Galaxy 4R satellite - Overview of the Hughes-built HS601 HP model spacecraft.

Explore the Net
Arianespace - European launch services provider that uses Ariane 4 and 5 rockets to carry satellites into space.

PanAmSat - Leading satellite communications provider and operator of Galaxy 4R once in space.

Hughes Space and Communications - U.S. manufacturer of Galaxy 4R satellite.

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