We don't know any projects categorized as flight-software yet.
C flight-software related posts
"This the first time we’ll be flying Linux on Mars. We’re actually running on a Linux operating system. The software framework that we’re using is one that we developed at JPL for cubesats and instruments, and we open-sourced it a few years ago."
2 projects | reddit.com/r/programming | 19 Feb 2021
Mars becomes the 2nd planet that has more computers running Linux than Windows
4 projects | news.ycombinator.com | 19 Feb 2021