I doubt we will be able to colonize solar system before current civilization dies (Expanse style)...
There is a lot of hints that it can happen pretty quickly.
I think the biggest obstacle is getting out of the gravity well and it's being solved right now.
I expect Starship will fly regularly to space in the next decade.
It is quite close to the aviation sector after WW1. Loads of rich people in barely flyable planes.
Colonization will take a while because we will not need people up there for a while for stuff we can do with robots.
After a while we should get basic factories up there and that's when it will start to take off. When the value of building in space is higher than bringing rare metals or rare In space manufacturing down.
If I had to give an optimistic timeline :
- 2030s - Back on the moon - Private space station - Very High value manufacturing (medecine, etc)
- 2040s - One shot First steps on Mars - High value manufacturing (Fiber optics, Chips) -
- 2050s - Robot Space Mining for refueling - Commercial space flight for high earners
- 2060s - Space Mining for high value metals - Science station on Mars
- 2070s - Commercial space flight for average earners
- 2080s - Commercial space Holidays for average earners - Small commercial Holiday station on the moon
- 2090s - Space Mining for low value metals - Low value manufacturing (Steel)
- 2100s - Small commercial Holiday station on Mars
- 2110s - Start of run-away Colonisation of Space.