[wizeman]

> At the very least, I would want to assume any civilization capable of interstellar travel to be at least 1000 years ahead of us, technologically.

My guess is that we'll be able to develop human-level artificial intelligence a lot sooner than 1000 years from now.

At which point it would be a lot easier to send AI probes to explore the galaxy and/or make first contact with another civilization than to build a generation ship.