A cool example of this was NASA's Deep Space 1 probe. The control system was written in Lisp. There was a race condition in the code that wasn't detected during

A cool example of this was NASA's Deep Space 1 probe. The control system was written in Lisp. There was a race condition in the code that wasn't detected during ground testing. NASA software engineers were able to remotely debug and patch the code while it was still running. ti.arc.nasa.gov/m/pub-archive/176h/0176%20(Havelund).pdf