I was at Ron's conference talk, and I remember it differently. The spacecraft had a problem, but was not allowed to run on lisp. Hence debugging and fixing it i

I was at Ron's conference talk, and I remember it differently. The spacecraft had a problem, but was not allowed to run on lisp. Hence debugging and fixing it in a repl was impossible. But Ron wrote a simulator in lisp, and could verify the necessary procedure in his lisp simu. The C code was patched and the spacecraft survived the reboot. But after re-reading the paper I could have mixed it up, and lisp was indeed in space, and was only killed later. I often remember his story, and often implement similar simus for my firmwares. And very often such a simu is the best tool to find bugs or to verify patches.