Arianespace has announced that potential post-Block-2 upgrades for the Ariane 6 rocket are currently under assessment. These “Block 3” improvements will likely be introduced in the 2030s if approved.
During an Ariane 6 Users’ Club event that took place at ESTEC two weeks ago, Arianespace outlined the current Block 2 Ariane 6 upgrades, which are expected to be available from the end of 2026. This variant of the rocket will include the more powerful P160 boosters, a more powerful Vinci upper stage engine variant, and improvements to the lower liquid propulsion module. The upgrades are expected to increase the rocket’s payload performance to low Earth orbit by approximately two tonnes.
In addition to outlining the Ariane 6 Block 2 upgrades, the company also revealed that post-Block-2 improvements were under assessment, with the potential of improving the rocket’s payload performance to lunar transfer orbit from 8.6 tonnes to 9.9 tonnes. This would enable the rocket to launch the ESA Argonaut lander with a single launch.
Argonaut is expected to be a multi-use lunar lander that will be capable of delivering up to 2,100 kilograms of cargo to the surface of the Moon. According to ESA, the lunar lander will have a launch mass of around 10 tonnes.
In an interview with SpaceNews in June 2024, ESA director of space transportation Toni Tolker-Nielsen said that the agency would only decide on whether or not to proceed with Block 3 upgrades in late 2025 during its next ministerial level council meeting.
If this subsequent set of Ariane 6 upgrades is not approved, ESA is also exploring multi-launch Argonaut missions. In this scenario, two Ariane 6 rockets would be launched—one equipped with a fuel reservoir and the other with an Argonaut lunar lander with its payload and a small amount of fuel. The pair would then dock to fully fuel the lander ahead of its journey to the Moon.