Both variants will lean heavily on technologies already proven or under development for Ariane 5.
They will also borrow elements from Europe’s small Vega launcher. The “2” and the “4” in the version names refer to the number of strap-on solid-fuelled boosters that do the initial lifting off the pad. These boosters will be the same as Vega’s first firing stage.
The hope is that the commonalities between the different rocket types will help drive down costs.
Airbus Safran wants further economies by employing more modern methods of production and from streamlining assembly lines.
“We have chosen an optimised industrial organisation where we will try to maximise the rate of use of production tools. For example, there will be only one place for the machining of the big metallic structures. And we will of course be using additive layer manufacturing (3D printing) and processes like friction stir welding. We will be investing in new tools.”
For its part, Airbus Safran does not envisage making Ariane 6 recoverable, not in the short term.
Mr Charmeau believes that different market conditions apply in Europe and the US, which means there will not be a single, winner-takes-all approach.
He cites, for example, the restricted procurement that exists in all major political blocs, which essentially bars foreign rockets from launching home institutional and government satellites. Nowhere is this more true than in the US, but in Europe too there is an “unwritten rule” that European states should use European rockets.
Mr Charmeau added: “And we have other specificities in Europe, such as the technology of propulsion, which is much better than the US one, both in solid and cryogenic propulsion. This allows us to launch [two satellites at once], which is another factor for competitiveness, maybe much better than re-usability – we will see in the future. And one characteristic, for example, is that we have only one (main) engine on the Ariane 64, whereas our competitor is going for re-usability because he is using much more engines. (The Falcon 9 has nine engines on its first stage.)
Long term it is hard to envisage Ariane shunning re-usability, and Airbus is studying a concept called Adeline that would modify the 62 and 64 variants to allow their main engine to fly back to a runway after consuming its launch propellant.
Whether Adeline, or some other re-usability concept, ever sees the light of day – and it would not be before 2030 – will ultimately come down to the attitude of European Space Agency member states. They fund the R&D of the Ariane programme and they may feel the American competition demands a response.
But like Mr Charmeau, Esa’s director general, Jan Woerner, is not rushing to judgement.
“There is no magic formula with one global validity,” he told reporters earlier this month.
“So, don’t say ‘this is the one and only solution’. We have to find a way to the best launcher for Europe; and we are doing so.
“I could talk for two hours about the advantages or disadvantages of re-usability. Is it appropriate for the European situation? I don’t say ‘no’; I don’t say ‘yes’. I just say ‘we’re discussing it’; we’re looking into it in detail.
“But just look to your daily life: you are buying returnable bottles or one-way bottles, and obviously for both there is a market.”
For more information on welding see: https://weldaloy.com/the-laymans-introduction-to-friction-stir-welding/