Aven Colony
48 Achievements
40-48h
Sol Survivor
Survive for 50 sols in any mission
3.9%
How to unlock the Sol Survivor achievement in Aven Colony - Definitive Guide
If your colony is stable, set the speed to 8x and let the game run while you do other things. Just keep an eye out for morale... if it gets too low and there's a referendum, you might actually lose and have to do it again. That's why I suggest doing it in a mission with the Unity artifact (especially Tenari Glacier) - activating it will give the morale a significan boost, if it's necessary.
To make the colony stable, enable some policies (auto repair drones, free gaming etc.), make sure you have enough power, drone coverage, turret coverage... lower immigration rate (you don't need more people).
Since you have a lot of time on your hands, you can work towards other achievements (like uncovering the fog on the expedition map), manufacturing candy etc.
This can be done on any mission that you have stabilized and protected. The hardest part will be to ensure your colonist are at least 50% happy with you so they don't boot you out during referendums. Stop immigration and ensure all colonists are employed and happy. Speed the game to 8x and disable the "crisis" speed option in the options menu (Options => Crisis Speed => Off). This will take upwards to two hours to complete from scratch but doesn't have to be done in one sitting, thus you can save your game and come back later.
This can also be done in Sandbox mode with the following settings:
Map: Any
Starting Resources: High
Environmental Events: Off
Mission Objectives: Population Growth
Morale: Very High
Minerals: Extreme
Referendums: Off
Cargo Pods: Extra Resources
Resupply Pods: 3 Beacons
Expedition Difficulty: Easy