First off we would need copy able plans of buildings. I am not a coder but it my opinion it would not be very very hard to do something like this. Now i dunno if this is even possible, and while i seriously doubt that itll ever happen, im curious what others think of this idea. Add more weapon hardpoints, better engines, more efficent reactors, better weapons, buy more skilled crew, better storage, better AI ect. Make ur ship stronger with better armour, from steel, to plasteel to even some sort of lightweight composite. Land on a new rimworld, and live in ur landed ship as u scavenge for resources to upgrade it. Enact ur own repairs or take ur ship to a professional. U could buy guns to mount on ur ship, or build them yourself.

Ur guys will require food and oxygen, or you could just shove them in thier cryptosleep pods and control the ship using the AI core, saving u valuable resourses. You could blast out the wall of the enemys armoury, then board them, and take over thier ship while they are unable to fight back because all thier good guns are inaccsesable. There could be a whole ship vs ship system, where, like ftl, critical componets are key to victory, and ur ship could have an armour rating and and take damage is specific areas of the hull. U vould board and attack other ships and space stations, invade a mechanoid hive, attack midworld cities, subjegate tribes, and leave colonies on multiple planets, which u could come back and visit when u want. This could mean that thier story could continue on over many planets. U could explore a random gen star map and take ur colinists out anywhere. Youd could have hydroponics on board to make food, or just buy it from traders, or grow it while landed on another planet. Imagine u could take ur colinists out and control your spaceship, which u built, as u explored a galaxy. If u had hull parts, consoles, storage containers, oxygen generators, medical compartments, thruster engines, weapon hardpoints ect. Imagine u could build an actual spaceship.

I was thinking a while ago about the rimworld ship building mechanic. For anyone whose played FTL (faster than light) they know that it is a decent space game.

Ftl make your own ship