Gene Roddenberry’s initial pitch for Star Trek was “Wagon Train to the Stars”, referencing a Western TV show that had been popular for over six years. It was a nice shorthand phrase that got across the point that although this was a Science Fiction show, it would really be a Western at heart.
When people talk about sending space explorers to other stars, journeys that can take thousands of years — but perhaps only a few years in subjective travel time, if you have enough energy to accelerate to nearly the speed of light.
The problem is that once you get to that other star system, everyone you have known back on earth will have been dead for the last few thousand years. There is no point in trying to communicate with them, since they are long gone.
But maybe we can think about all of this another way. If our goal is to maintain a sense of connectedness, community, and cultural identity, perhaps we can literally build connectedness into the process.
Rather than sending a lone ship into the wilderness, future humans can periodically send ships into the same trajectory. Over time, this will create a long string of ships, each with two nearest neighbors (the ship before and the ship after), as well as some limited access to other ships that are farther away in the ever expanding train of ships.
Yes, there will be relativistic differences between ships, since each ship will be traveling in a slightly different relativistic time frame as its neighbors, but communication will still be possible, and therefore a sense of cultural connection.
Over the length of the entire vast chain of ships, many different cultures might develop, even different languages, just as humans have historically developed different cultures and languages when geographically separated.
Yet there will be coherence, and a sense of a single species will be maintained. Most important of all, there will be true human intelligence aboard each ship, so that any message sent or relayed from one ship will be received by sentient minds, who will be able to decide, before too much time has passed, what to do in response to that message.
It will truly be a wagon train to the stars.