I think theoretically, you could make money refining rare minerals from asteroids (like platinum, gold, rare earths). The issue is that since the startup cost is so high, the mission is very risky (conservatively, it would probably cost in the 10s of billions to be able to refine anything at scale) and 10s of billions worth of rare minerals won't stay worth 10s of billions since the world only needs so much minerals - the price would fall substantially.
I think the only thing really worth doing in space, economically speaking, will be energy related. Maybe harvesting helium 3 will be lucrative. Maybe (I doubt it) there will be a profitable way to harness solar energy - could be more profitable if we can produce the panels in space by the asteroid they are procured from, but then the issue is transmission.
Actually, there is another thing. I think space tourism could be lucrative. Imagine if you set up a lunar colony for 20b that could house ~1k people with about 200 permanent staff. If 800 people are paying $100k/week (plus cost of transportation) to stay up there, you're making $4b per year. Personally if I were worth in the ~10s of millions I would absolutely shell out $100k to spend a week on the moon so I think this kind of thing could work
It is still only a playground for the rich and wealthy. The Space industry needs to become like the Airline industry in minimizing the accidents and making it safe and cheap enough for the average person to afford.
There are people who want to go into space to be like Captain Kirk or some other scifi character. Some of them are rich or wealthy and can afford the $100K a week on the Moon.
Thing is a moon-base has to avoid meteorite strikes and other hazards. If the water or oxygen gets contaminated that's it for everyone.
Breakeven D-T fusion has never been demonstrated, at any scale. ITER won't even attempt D-T fusion until 2035, and then you need to figure out how to scale the reactor down until it doesn't cost $50 billion and 50 years to build, and also increase the collision energy until it can actually do D-He3 fusion, or even higher, true aneutronic He3-He3 fusion. Yes, yes, Stellarator, Polywell. Neither have been built.
Or you can just do solar and batteries. Which exist today.
>space based solar
Tom Arnold did the best post on SBS back in 2012: https://dothemath.ucsd.edu/2012/03/space-based-solar-power/ Depending on what downlink power density you're willing to tolerate, how big of a transmit dish you can assemble in orbit, and how big of a receive array you want to build on the ground, you only get maybe four times the power density of the sunlight falling on the ground taken up by the rectenna array.
Awful lot of work to go to just to get four times more power per square meter on the ground.
And if you've got the room for a rectenna array 4 km across for SBS, you might want to just build a regular terrestrial solar array 8km across instead, and save a few dozen billion dollars in launch costs.
I think the only thing really worth doing in space, economically speaking, will be energy related. Maybe harvesting helium 3 will be lucrative. Maybe (I doubt it) there will be a profitable way to harness solar energy - could be more profitable if we can produce the panels in space by the asteroid they are procured from, but then the issue is transmission.
Actually, there is another thing. I think space tourism could be lucrative. Imagine if you set up a lunar colony for 20b that could house ~1k people with about 200 permanent staff. If 800 people are paying $100k/week (plus cost of transportation) to stay up there, you're making $4b per year. Personally if I were worth in the ~10s of millions I would absolutely shell out $100k to spend a week on the moon so I think this kind of thing could work