ESA to Modify Ariane 6 for Future Nuclear-Powered Argonaut Missions
ESA will adapt the Ariane 6 rocket for future Argonaut lunar lander missions that carry a Radioisotope Power System. The modifications are not required for the lander's first mission, which is scheduled for 2030 and will carry up to 1,500 kilograms of cargo.
The European Space Agency (ESA) will adapt the Ariane 6 rocket for future Argonaut lunar lander missions that carry a Radioisotope Power System. The modifications are not required for the lander's first mission, which is scheduled for 2030 and will carry up to 1,500 kilograms of cargo.
Baseline Launch Vehicle
ESA has chosen the Ariane 64 Block 2 as the baseline configuration for Argonaut missions. This variant features the P160C boosters and the Vulcain Aft Bay evolution. The agency previously expected the lander to require the now-shelved Ariane 6 Block 3, but recent assessments have lowered the performance requirement.
| Variant | P160C Boosters | Vulcain Aft Bay | Performance Status |
|---|---|---|---|
| Ariane 64 Block 2 | Yes | Yes | Baseline for Argonaut |
| Ariane 6 Block 3 | Not specified | Not specified | Shelved |
Safety Adaptations
According to an ESA spokesperson, specific adaptations will be required for Argonaut missions carrying a Radioisotopic Power System. These adaptations relate to safety measures for launching payloads with radioisotope power systems. The spokesperson added that these changes will not be necessary for the lunar lander’s first mission, as it will not carry a radioisotope power system.
Radioisotope Development
ESA is developing European radioisotope heating and power systems through its ENDURE programme. An initial demonstration flight of the technology is planned for 2028 aboard the agency’s Rosalind Franklin mission to Mars. The mission will use a European-developed americium-241 radioisotope heating unit on its lander.
Performance Assessment
A joint task force that worked from 2023 to 2024 assessed the lander’s launch requirements when ESA’s Human and Robotic Exploration directorate targeted a higher performance level that would have required the upgraded Ariane 6 variant. Subsequent system-level assessments have enabled ESA to reduce that requirement, with the latest mission definition now considered compatible with Ariane 64 Block 2.
Two-Launch Architecture
Teams also assessed a two-launch architecture that would launch Argonaut with its payload and a small amount of fuel aboard one rocket, and its full fuel complement aboard another. The two would then dock in orbit to refuel the lander before its journey to the Moon. With flight data from its first half-dozen flights supporting higher performance estimates for Ariane 6, a two-launch approach is no longer under consideration.
Flight Data Analysis
The spokesperson said that flight data analysis of the Ariane 6 launches already performed allowed ESA to significantly increase the achievable performance of Ariane 6. Ariane 64 Block 2 performance will be compliant with the Argonaut mission as currently designed. A two-launch architecture is not considered.
Mission Timeline
The first Argonaut mission is currently targeted for launch in 2030 aboard an Ariane 64. The mission will include two technology demonstrators. The first will explore the landing area and test technologies, including systems that will enable it to survive the lunar night. The second is designed to demonstrate robotic technologies using the lander itself for future European lunar missions.
