In the context of writing reliable software for a spacecraft? Pretty much anything with a reasonable type system, for a start. Maybe C#, or some reasonable subset of C++20, or Rust. Maybe Reason or OCaml.
I mean very clearly the good people at SpaceX have heard of these languages and decided against it. I think JS and Chromium are the best UI kit I can think of in terms of man hours to get X done. If you're careful the only thing I've ever had issues with is latency, but in space if you're in a situation where missing a frame or two is important you're already beyond fucked.
Many people are using TypeScript these days, it works very well.
I like C# and Rust too. I've built UI's in C++ and MFC/OpenGL/DirectX. It remains my fairly strong opinion that JavaScript is well suited to UI development.