I ultimately see space as humanity's ultimate home. Not in the Star Trek or Star Wars sense (because I don't belive FTL communication or travel is possible) but

I ultimately see space as humanity's ultimate home. Not in the Star Trek or Star Wars sense (because I don't belive FTL communication or travel is possible) but instead as a Dyson Swarm. A Dyson Swarm is a collection of orbitals. With current technology and materials we could build O'Neil Cylinders that are 2-3 miles wide and 10-20 miles long that could house millions of people if necessary. Cover the whole thing in solar panels and fly enough of them around the Sun to capture the total solar energy output and you have an unbelievable amount of energy at your disposal and an unfathomably large amount of living area. It's estimated humanity currently uses 10^11 Watts of power. Using all the sunlight that hits Earth would take that to 10^16 Watts. The orbitals of a Dyson Swarm take that to 10^26. This can be built incrementally and requires no new physics of theoretical materials. It's just a truly massive engineering problem. The most important problem we have now is reducing the cost of getting payloads into orbit. The Apollo/Shuttle era had costs of around ~$50,000/kg. Factoring in reuse, Falcon 9 may well be under $1,000/kg now. Starship may ultimately take this down to $100/kg. This needs to keep getting cheaper. But here's my big problem with the stations we're building like the ISS and what the Europeans want to build here: they're all zero-gravity. What we should be doing is working on spin gravity stations to work out the issues and see how humans cope with that long term. Yes, zero-gravity is useful for experiments but this isn't an either-or situation. You could have a spinning wheel attached to something not spinning for zero-gravity work environments.