A rulebook that says who should be hacking away when, and how/when/from where to get and/or produce more of those people. That long-lived superstructure is what

A rulebook that says who should be hacking away when, and how/when/from where to get and/or produce more of those people. That long-lived superstructure is what NASA calls a "mission." It's what ensures someone will still be around (with the right expertise, budget, connections, and tools) to fix a satellite when it breaks 50 years later.