I love bumming around in Sol for a long time with a low pop conventional start. So now, some forty odd years after the start, I’ve started to venture out into the black and actually used a jump point. The motherlode is on the other side. Now since I started low pop, my industrial base isn’t huge yet. Earth is up to 849 pop with 504 CF. How would you go about this expansion?
The biggest bottleneck early on is corrundium - the mineral you build mines with.
With that in mind, I would start a mining moon in A-IV 3. If possible, and that moon is also terraformable, also colonize it.
if it’s terraformable, start shipping infrastructure, colonists, terraforming installations and mines.
If not, automated mines and a mass driver directed to a terraformable planet, where it will have infrastructure, mines, mass driver and a spaceport.
Ship the corrundium to earth, where you will build more automated/mines, and repeat untill you can get a respectable amount of corrundium. At the same time, if possible, build more CF.
Suppose you have a colonized planet with a spaceport, add mines to the rest of the system with a mass driver to the colony, and ship a y minerals to earth.
I agree with Roey.
Moreover, to obtain the help of the civilian freighters and move the structures from Earth to the colony, you can set demands (for the colony) and supplies (from Earth) in the Civilian/Flags tab in the Economics window.
Be aware: to have this, some tens of thousand of colonists must be on the new colony.
It’s a pretty good system overall, as mentioned putting mines on A-IV 3 for corundium and terraforming it (if the orbit is ok) is a good start but I would probably go a bit further, because other than low amount of Uridium this has the potential of getting used as a sector capital system.
I would start also settling and terraforming A-II (should not be too complicated, it’s not a huge planet as long as the orbit is ok), mine the minerals there and put some limited maintenance MSP production here while I search nearby systems for Uridium. If there isn’t it could always be shipped. You can permanently base a couple of ships here to protect nearby systems. You can also bring the mining product of nearby systems to A-II to centralize them before shipping to earth.
After the system has developped a bit and has some population you can start sending construction building or engineers to start developping native production capabilities.
What you have here is pretty good quantités of almost everything (even if the accessibilité isn’t good everywhere), with a very central, low colony cost planet which hopefully shouldn’t be too hard to colonize, so this could be used as a production center eventually and a local logistics hub quite easily.

