First of al, I think my proposal fits this discussion better then proposing it as an idea / suggestion as this came up in me because of this open discussion.
To answer the questions at the opening post. I feel like the colonies are a great feature to improve immersion. Something that fits space ages extremely well. Without it the space ages wouldn't be half as enjoyable and interesting, if you ask me.
Proposal
I've an proposal that answers most of the community desires, regarding space colonies. The ability to revisit an previous colony and to regain acces to exploration sides.
In a nutshell
Make space colonies work like cultural settlements and make access to exploration sides on space age cmap dependent of active space colony instead of current space age. Also, introduce the option for granting independence to space colonies.
Extended explanation & fully worked out proposal:
Unlocking the different space colonies
Up on reaching an new space age, you'll unlock a new space colony of that age. Similar how Aztecs are unlocked in colonial age, for cultural settlements.
Independence
Up on reaching Space Age Asteroid Belt, you'll be able to grant independence to your active space colony. After which you can select a new colony.
Independence works the same as abandoning an cultural settlement. You'll lose all credits and expansions, additionally you'll losing access to the exploration sides of respective space colony.
For example when you'll grant independence to your Mars colony you can't use Mars ore exploration sides. Until you start a new Mars colony.
To be clear, when you enter SAM your Mars colony starts automatically just like now. Only up on entering SAAB you'll gain the option to make your SAM colony independent and starting your SAAB colony whenever you decide. You can also grant your SAAB colony independence whenever you see fit and building up a new SAM colony instead. This works the same with SAV and later space ages.
Selecting space colony
After your previous colony became independent, you can start a new space colony.
In the selection are the space colonies you've unlocked. This works the same as with cultural settlements when you'll selecting an cultural settlement. For example in Space age asteroid belt, you can choose Mars or Asteroid belt. In SAV you can choose between Mars, Asteroid Belt and Venus.
(re)gaining acces to (previous) special resources
When you choose an colony of an previous space age, you'll regain access to the exploration sides of respective space age. For example I'm in SAAB and grant my SAAB colony independence. Then I slecht the SAM colony. Now I can obtain Mars ore from the cmap again. However I'll lose access to asteroid ice exploration sides. As those are from SAAB colony and not SAM.
In this way you can switch between Space resources as you decide. The drawback is that you must choose between those you've already unlocked. The colony also starts at 0, like cultural settlements. Expansions are lost and all buildings and credits. Unlike cultural settlements are still all colonial buildings available to be build. Since they where unlocked from the tech three.
Disclaimer
This proposal is not DNSL, as such;
"Making the game easier"
This proposal does not affect the difficulty of the game. It rather enables new strategic chooses to make.
"Extreme changes"
This proposal does not radically changes the way colonies work, nor how space ages work. The game mechanics remain the same. Colonies will only become more like cultural settlements.
Also, the Mars Ore/Asteroid Ice on the map should remain available. My 2 cents.
