Countdown to the maiden launch of the Ariane 64, Europe’s most powerful rocket

VERNON, France — In a tightly controlled manufacturing hangar west of Paris, workers are putting the finishing touches on a massive silver engine. In a few days, a similar device will power the most powerful version of the European Ariane 6 rocket to date, flying for the first time with four thrusters.

On Thursday, the Ariane 64 rocket – named for its four boosters – is set to make its first launch from Europe’s Kourou spaceport, French Guiana, with the aim of deploying 32 satellites for Amazon’s Leo broadband constellation.

The flagship of the European rocket industry is battling in a highly competitive environment against heavyweight players from around the world, including global market leader Elon Musk’s SpaceX.

At the ArianeGroup plant in Vernon, engineers design, integrate and test the engines of the European heavy launcher. At another site west of Paris, in Les Mureaux, the components of the rocket’s main stage are carefully constructed and assembled.

Associated Press journalists were given rare access to facilities subject to strict security and confidentiality rules, where teams of highly specialized workers make the conquest of space a daily reality.

“It’s a special launch, something new for us on Ariane 6,” said Hervé Gilibert, technical director of ArianeGroup. This flight marks the debut of the four-booster configuration, making the rocket about twice as powerful as the version used since 2024, he said.

“Don’t be surprised if you see it accelerate much more than Ariane 62, the version we have already launched five times,” Gilibert said. “It provides much more power, allowing much heavier payloads to be sent into space.”

The launcher, its engines and its avionics are built throughout Europe since 13 countries, members of the European Space Agency, have agreed to cooperate and finance the Ariane 6 program.

“We work with more than 600 subcontractors,” explains Gilibert. “Everything is gathered on two main sites: Bremen in Germany for the upper stage and Les Mureaux in France for the lower or main stage of the launcher.”

Before Thursday’s launch, all components crossed the Atlantic to French Guiana for final assembly. The rocket is approximately 62 meters (203 feet) tall, or roughly the height of a 20-story building.

“We check everything until the last minute, then we fly,” Gilibert said.

Once airborne, the mission will last about an hour and 50 minutes – almost a full orbit around Earth – before the satellites are deployed in pairs from the top of the rocket. Amazon’s Leo constellation is intended to compete with SpaceX’s thousands of Starlink satellites.

The Vulcain 2.1 engine built in Vernon ignites first on takeoff.

“For a few seconds, we check that it is working correctly,” explains Emmanuel Viallon, director of the Vernon site. “Once we are fully confident that it will operate properly for the next eight minutes, we ignite the solid boosters and the rocket takes off.”

The four boosters help power the rocket at launch, consuming 142,000 kilograms (313,056 pounds) of solid propellant in just over two minutes until they burn out.

Ariane 6, both in terms of its launcher and its engines, was designed to halve operating costs compared to its predecessor, Viallon said. Ariane 5 was last launched in 2023, concluding a program launched in the late 1970s to give Europe independent access to space.

Engines produced in Vernon are tested on site under near-real launch conditions. Deep in the surrounding forest, reinforced structures hold the engines in place when firing at full power, while test teams operate from underground control rooms.

Laurence, director of engine firing testing in Vernon, said the full test cycle takes two to three weeks, before the engines return to the assembly plant for final adjustments. Laurence’s last name has not been released for security reasons.

For the team, each launch “is always a joy, it’s always very intense,” she says. “When an engine arrives here, those are really important moments for the team. And then to see that the launch goes well… it brings a lot of gratitude.”

In Mureaux, engineers began preparing the rocket components for upcoming missions. Huge white cylinders sit horizontally to form the rocket’s main stage which is 5.4 meters (17.7 feet) wide and includes supercooled hydrogen and oxygen tanks that will power the Vulcan engine.

Caroline Arnoux, business unit director at ArianeGroup, said seven to eight launches are planned this year.

“We have a very solid order book, equivalent to around thirty launches,” Arnoux said. “About a third are institutional missions and two thirds are commercial. And our commercial customers are all waiting for the Ariane 64 version, which will be extremely important in the years to come.”

Ariane 64 “is an additional level of performance,” said Hermann Ludwig Moeller, director of the European Space Policy Institute. “In itself, this is an important step in the overall program, hoping to demonstrate that this configuration works as reliably as Ariane 6 has so far.”

The rocket’s institutional missions last year included the launch of a French military reconnaissance satellite, a weather satellite, as well as EU-sponsored Earth observation radars and navigation satellites.

Moeller said there could be little comparison with SpaceX, which dominates the industry with its reusable rocket design.

SpaceX “builds the rockets, builds the satellites and also sells the service,” while Europe operates under a different industrial setup with separate companies responsible for the launchers, manufacturing and operating the satellites, he said.

For Ariane 6, a major challenge will be to diversify its European customer base, which could involve a European preference system for government missions and further development of commercial markets across the continent, Moeller explained.

Independent access to space remains the central objective of the program to “enable Europe to meet its own needs”, underlined Arnaud Demay, Ariane 6 project manager.

ArianeGroup is also preparing for the future by working “on key technological building blocks… to enable the reuse of certain launcher components. Ideally, we would like to be able to reuse an entire stage, including the engines that ensured its takeoff,” Demay said.

Demay says he almost always cries with emotion when he sees the rocket take off.

“We do it so rarely, and it’s so majestic when it takes off: that little touch of magic inevitably overwhelms me with emotion every time,” he said.

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Nicolas Garriga contributed to this report.