[dchichkov]

I'm not sure about the obsession to go to Mars. What is the rational behind it?

The next right step in technology (that would allow real progress in space exploration while having good environmental impact) is fusion energy. Developing chemical rockets to send a human to Mars seems like a misguided endeavor.

Without focuswe may run out of runway to develop and deploy clean energy technology - https://xkcd.com/1732/

[meatsauce]

What is the rational behind it? Sagan said it best:

“For all its material advantages, the sedentary life has left us edgy, unfulfilled. Even after 400 generations in villages and cities, we haven’t forgotten. The open road still softly calls, like a nearly forgotten song of childhood. We invest far-off places with a certain romance. This appeal, I suspect, has been meticulously crafted by natural selection as an essential element in our survival. Long summers, mild winters, rich harvests, plentiful game—none of them lasts forever. It is beyond our powers to predict the future. Catastrophic events have a way of sneaking up on us, of catching us unaware. Your own life, or your band’s, or even your species’ might be owed to a restless few—drawn, by a craving they can hardly articulate or understand, to undiscovered lands and new worlds.

Herman Melville, in Moby Dick, spoke for wanderers in all epochs and meridians: “I am tormented with an everlasting itch for things remote. I love to sail forbidden seas…”

Maybe it’s a little early. Maybe the time is not quite yet. But those other worlds— promising untold opportunities—beckon.

[mavhc]

Going to Mars is easy compared to Fusion, just requires, say, $100 billion. It's been possible but too expensive for decades, the idea of Starship is to make it cheaper.

Then it's just a logistics problem.

Plus whoever founds the successful human civilisation on Mars gets into the history books, fusion is a massive team effort that won't have one specific person remembered.

[tsimionescu]

Going to Mars is easy. We've even done it twice in the last 5 years.

Making a self-sustaining city on Mars is impossible. And even if not impossible, certainly costs many tens of trillions of dollars, which is as good as.

[evandale]

Impossible is pretty strong. Who knows, maybe there's material that can be used for construction buried 100 feet under the surface. Or we figure out how to build stuff with Mars dirt. Humans are the most resourceful and adaptable beings in the universe (that we know of) and life, uh, always finds a way.

[mavhc]

How many tonnes of stuff will it take to be self sustaining?

1 million was estimated, which would cost $100 billion

[WalterBright]

There's no reason we cannot work on these in parallel.