New possible backstory:
At some point a species of beings will have advanced and expanded to such a degree that their home planet can no longer sustain them.
Sometimes when this happens they just die out eventually. But for a small fraction of these species, a device crashes into their planet. Species who this has happened to have met and exchanged information, but no one knows where these devices come from.
The device, upon investigation turns out to be a massive computer. An artificial intelligence.
It shares information with the species and gives them a choice, use this new information and the last of their resources to send a select group of the population into space to survive. Or reject the technology and die.
Those who choose survival exhaust the last of the planets resources using this new technology made available through theto construct a massive ship. Now orbiting the planet like a moon awaiting it’s selected crew to arrive, and to part their own home, leaving the remainder of the population on a dead planet, a sacrifice for the future.
Now on their way to explore a vast new universe, free from the ties of their former home, free to do whatever they want!
Or are they…?