> Ariane 6 exists so that European countries can get independent access to space between now and 2030s.
No it doesn't. That directly contradicts the actual rational for Ariane 6 as outlined in 2014.
There were two options, Ariane 6 or Ariane 5 ME. With France principally favoring Ariane 6 and Germany Ariane 5 ME. With Ariane 6 costing many billions, and Ariane 5 ME costing a few 100 million $.
The Ariane 5 ME would have done the 'independent access to space between now and 2030s' just fine.
The explicit reason why they wanted Ariane 6 was to remain competitive against the Falcon 9. They were starting to lose launches on mass to Falcon 9 already by 2014 and were panicking.
Its simply PR spin to now pretend this never happened. But rather admit that they spend 5 billion $ to lose the commercial market anyway and were basically now subsidizing uncommunicative launches for US cooperations instead.
Ariane 6 achieved the exact opposite of what its rational was in 2014. Instead of helping Europe pay for its space industry, it has to be subsidized.
> 6-10 years from now Ariane Next/SALTO will aims replicate Falcon 9 efficiency and the design will be very similar: reusable, RP-1/LOX, Prometheus engine is similar reusable open cycle engine as Merlin with lots of 3D printed parts.
Sure in fantasy land this is true. The reality is, after the gigantic expanse of Ariane 6, that cost way more then expected. With Europe having huge debt and Ukraine was, plus very expensive new space systems, there is very little actual drive towards a new large rocket system.
Such a rocket system would again cost many, many billions and this will be politically impossible, not just because of the money.
Beyond the rational mentioned above, the reason Ariane 6 was picked, was that France was willing to give solid booster contracts to Italy. So France literally 'paid off' Italy to get them on board Ariane 6.
The reality is, Italy simply will not wnat to move away from solids. And Germany is, very, very, very unlikely to be onboard for another gigantic rocket investment, after they already didn't want the Ariane 6 in the first place. Without Germany and Italy there simply isn't gone be a 'next big European rocket'.
Between your optimistic 6 years prediction, I would say 2040 is a much more likely date then 2030. We have already seen delay with the test platforms. And we are already seen a collapse of the 'all ArianeGroup' all the time mantra that Europe had. The idea that ESA would hand ArianeGroup another 5 billion $ in the current environment just isn't gone happen.
And this is simply because of exactly what people already pointed out in 2014. Wait until the technology is ready, and then develop a next generation rocket, rather then rush out a sub-optimal design 'quickly'.
Now they have shot their powder and are stuck on a slightly improved Ariane 5 rocket with no reasonable path for upgrade. Exactly as many critics have pointed out in 2014.
> reusable, RP-1/LOX, Prometheus engine is similar reusable open cycle engine as Merlin with lots of 3D printed parts.
Prometheus has been in development since 2015 already, and they are not even at full duration testing yet. Bragging about a new GG engine today isn't that impressive, not for a space power that has been making engines for decades.
RocketLab, has just recently switched from Gas Generator to Staged. And with much less money their Archimedes seems to be developing much faster then Prometheus while being much more advanced.
Europe is just being out executed in so many way. RocketLab will basically develop a complete new rocket and advanced engine for a cost comparable to what Europe spends on engine development and re-usability test programs.
RocketLab will put this stuff into commercial deployment a decade before ArianeGroup despite having started years later.
Sorry, I'm not that impressed by 'maybe in 2035 we will clone SpaceX architecture from 2020' just with a much less optimized engine.