Sixty Years In Space is the officially licensed tabletop roleplaying game of the High Frontier board game, which means it already starts with all the hard rocket science that the board game includes. And the inspiration doesn't stop there: you'll be exploring the solar system, finding water and building factories just like in the board game except zoomed in to the scale of individual crew members rather than from the perspective of the mission control. But it doesn't limit itself to the practicalities of space exploration at a human scale. While you're in space, Earth society will be changing, including your mission control, and a significant part of the game is deciding how your crew reacts to the missions your are assigned and the technologies imposed on you.
The game is extremely crunchy - the core rules and first 4 supplements run to nearly two thousand pages - and covers everything from microgravity health risks to robots to colonies. Rather than having a fixed future, your crew will be responsible for defining and reacting to it over the course of their lives, with potential life spans measured in the millions of years or more. It also doesn't have a game master, instead relying on random tables to create missions, other factions, rewards and even space dungeons!; condensing systems modelling insolation, agricultural area and population distribution down into relatively simple maps generated by dropping different coloured counters and dice and placing playing cards. And if you're fascinated by the High Frontier board game map, the A Lot of Zeroes supplement has an appendix which provides guidance on how to create maps for solar systems other than our own.
It's hard to overstate just how much stuff is in this game, with small gems of insight on each page about what a part of a possible future in space might look like. But fortunately you can download the first 120 pages of the core rules for free along with a chapter on space infrastructure and terraforming from the This Space Intentionally supplement, even if you don't envisage playing the game with your regular gaming group.