gr-satellites ignores SIGTERM and doesn't always stop properly

The termination of gr-satellites at the end of an observation does not always work properly, leaving stale processes running and consuming memory until the system crashes.

This is caused by gr-satellites sometimes hanging indefinitely even though it was sent a SIGTERM signal.

Possible solution

Terminate gr-satellites with SIGKILL instead of SIGTERM, preferably as escalation after some grace period.