Hiya! Just popping in to add some quick information. The planets unlock for more missions as you move through the questlines.
This is the current info I have:
Omicron Persei 8– opens with the first space mission, “Cable Guy”
Mars– opens with the Downtown District
The Moon–opens with District 3
Chapek 9–opens with District 4
Earth–opens with District 5
That’s all the info I have on this right now. I’ll update if/when I get more or get there myself.