Many SF stories feature faster-than-light travel as essentially a trope: Roddenberry has stated☡ that the Enterprise travels at the speed of plot. As an allegory of the south seas, or some throw-away method to introduce people to a place to have an adventure or meet a different culture, it's just used to preserve the time scale we are used to.
But “hard” S-F has moved away from FTL over the last 20 years or so, and we see everyone from Greg Egan to Alastair Reynolds crafting mind-bending stories where the speed of light is still a hard limit.
But, more generally, how can we write an adventure story without FTL? How do you deal with the time scales involved? Even Egan’s universe seems less believable with society remaining unchanged for thousands of years while characters are transmitted at light speed.
How can characters encounter “strange new worlds” etc. without resorting to a trope?