2100 seems highly optimistic. We haven't landed a person on the moon in over 50 years. Space travel is really, really hard, and you're talking about sending probes light years away...
Imagine that for the first 50 years of aviation all airplanes had been single use, and then in the 1960s someone figured out how to make them reusable. Thats what’s happening with space flight. The next 75 years are going to be interesting.
I do think 2100 is a stretch, space is hard, but we’ll likely have all the basic elements of that proved out by then.
I think the biological difficulties of human space travel, and its unprofitably so far, have given us a very poor perspective on how fast thing progress from here.
Old bottlenecks are evaporating.
Reusable systems, cheaper faster rocket production, & the loss of dependency on traditional pilots are just three profound bottlenecks we have passed in the last few years.
Machines are getting smarter (not even talking about general AI) and smaller, launch costs are collapsing, demand for resources accelerating, and systems for refueling, communication, etc. are bifurcating.
The last & only BIG bottleneck left now, is simple recognition of relative economic profitability. Just as there has been an explosion of satellites, there will be an explosion of resource extraction the moment it becomes relative net profitable, on a forward predictive basis.
(I.e. shareholder returns for demonstrated viability relentlessly accelerate investment, long before positive cash flow is required.)
Human lunar & Martian bases are just a distraction, however intriguing and likely. They are not a brake on the Solar System resource economic loop, any more than the continued inefficiencies of biologically manned orbital stations held back the explosion of communication satellites.
That’s only 75 years away, same time since the first work on developing orbital rockets.
But by 2500 sure. And likely by 2500 some form of self sustaining asteroid with propulsion will leave the solar system.
I used to think ince that happens for a few thousand trips, humanity will survive enough that our descendants will last billions of years. Not the same biology, certainly not a single culture, but once the technology exists nothing can stop the spread.
I do think 2100 is a stretch, space is hard, but we’ll likely have all the basic elements of that proved out by then.