> Ada didn't prevent the Ada code in Ariane 5 from being a disaster

That's a weak argument to say that Ada could not lead to a better place in term of software. It's like saying that it's not safer to cross at a crosswalk because you know someone who died while crossing on one.

(But I guess that's fair for you to say that, as the argument should probably be made by the people that say that Ada would be better, and because they made a claim without evidences, you can counterclaim without any evidence :-) )

There are no programming language that can prevent a software for working correctly outside of the domain for which the software is written, which was the case for Ariane 501. Any language that would have been used to write the same software for Ariane 4 may have led to the same exact error. Ariane 501 failure is a system engineering problem here, not a software problem (even if in the end, the almost last piece in the chain of event is a software problem)