Ask Lemmy

Quite awhile; despite what some popular scifi depicts mars isn't really the best target out there for space colonies (and is too long a trip for short duration tourism), so first the technology and infrastructure to do those would need to be developed, and then the more convenient or economically attractive locations to set one up would have to be already taken, and then someone would need to have set up a mars colony and developed to the point where it isn't just a research base and actually has the capacity and use for a growing population, none of those steps are short things.

Especially that first step is tough, because launching large amounts of mass to space, let alone all the way out to mars, is incredibly expensive, so getting any of this started requires either a way to get to space without rockets (like space elevators or similar ideas, which require better materials than we currently can mass produce and would represent hugely expensive infrastructure investments to build once we have the ability), or the ability to extract and use raw materials in space to build, well, almost everything except the actual people to be sent there. Which is also something where the technology hasn't quite been developed, though progress has been made, and in any case is a bit of a chicken and egg problem because launching all that heavy mining and processing and manufacturing equipment to get it started is so expensive.

I would not personally expect things to get to a point where a middle class (or even typical rich person for that matter) can go to mars for several centuries, unless you count scientists sent by a government and not on their own dime. I do believe we'll get there, someday, but it's an incredibly long and difficult process, much more complicated than people like, say, Elon Musk make it out to be when they make wild claims about building a city there in a matter of decades.