For the first two (nuclear power and JSF) and the car I would probably use a language like SML or Haskell, or perhaps even a language like Coq (where your progr

For the first two (nuclear power and JSF) and the car I would probably use a language like SML or Haskell, or perhaps even a language like Coq (where your programs are mathematical proofs of their own correctness). For a Mars rover, probably a core written in the languages above, and then bootstrap Common Lisp on top of that core (the core would control critical things that will not need much room to change, Lisp for various AI related things etc.). Of course, I am not an expert on the requirements of all those projects. Maybe some fact about functional languages makes them entirely unsuitable. If there is a technical reason why C is being used, I would like to know it; if the reason is just, "Well that's what the libraries are written in, that is what most people know, there was a bunch of legacy code, etc." then it only proves that technical reasons are easily trumped by practical concerns. Like I said earlier, it is hard to get away from the large C and C++ codebase that we have to deal with today, despite all the problems of those languages and despite the widespread availability of better languages.