Earlier quoted context omitted.
Spaceflight has an inherently different set of requirements from the types of applications people on here mostly build. NASA doesn't need to run 2GB of javascript dependencies on their rover. They have people who can write lean real-time code in a low level language. They need to be sure a bit flip doesn't turn a 3 billion dollar project into rubble. There is no 'fix it in the next sprint' in spaceflight; after you h…
I used to know a number of NASA programmers out of Houston. They did a lot of Java programming on some pretty hyper-optimized and specified JVMs. They liked it because it would be easier for them to run simulations on and could achieve good portability on higher level things. That was like 20 years ago though. Things could easily be different now.
High Performance Java is definetly a thing - it just takes a lot of tuning.