The launch came as Europe seeks to strengthen its defences amid doubts about co-operation with the United States under new US President Donald Trump.
The launch means that Europe can now independently put large satellites into orbit for the first time since Russia pulled its heavy Soyuz rockets after invading Ukraine in 2022.
Ariane 6 was initially scheduled to enter service in 2020, but repeated delays meant the rocket did not blast off for the first time until July last year.
Its first commercial mission put the French military satellite CSO-3 satellite into orbit at an altitude of around 800 kilometres (500 miles) above Earth.
CSO-3 completes a network of three French military imaging satellites, with the first two launched in 2018 and 2020 on Soyuz rockets.
‘Europe must ensure its own security’
European Union countries have 10 military satellites, five French and five Italian, compared to “hundreds” for the United States and China, French General Philippe Steininger said.
Britain also has its own military communications satellite system.
“Europe must ensure its own security,” European Space Agency’s space transportation director Toni Tolker-Nielsen said in Kourou this week.
While five Ariane 6 launches are planned this year, Tolker-Nielsen said up to 12 could be carried out a year in the future.
An attempt to launch the mission on Monday was called off just 30 minutes before lift off due to a problem on a fuel pipes, Arianespace said.
Other planned launches in December and February were also scrubbed.
Postponed launches are common for new rockets. The latest test flight of the world’s biggest rocket, SpaceX’s Starship, is also scheduled for launch later on Thursday after a last-minute postponement on Monday.
The European space industry has struggled to remain competitive with Elon Musk’s SpaceX, which has become increasingly dominant when it comes to launching satellites.
And SpaceX is only expected to become more central to US space efforts now that the billionaire Musk has become a prominent adviser to Trump.
Europe has struggled in space since Ariane 6’s predecessor Ariane 5 retired in 2023, Russia pulled its Soyuz rockets and an accident grounded the smaller Vega-C launcher for two years.
But with Vega-C resuming flights in December and Ariane 6’s first commercial launch, European space efforts are looking for a boost.
Given the military role of the satellite, heavy security was deployed at the spaceport on the northern coast of South America, with French fighter jets deployed to patrol the surrounding skies.
Arnaud Prost, a French pilot who is also a reserve astronaut for the European Space Agency, said a successful Ariane 6 launch was “an important step for the independence of France and Europe’s access to space”.
“At the moment, Europe needs to find projects that bring us together,” he told AFP.
© Agence France-Presse