there’s many reasons to want to become a multi-planetary species
Yes but it’s a fantasy. The scenario where mars would be truly independant of earth is basically impossible without the far more likely reality:
If we survive that long, we won’t be squishy humans anymore. Uploaded, AI, genetically engineered biotech, take your pick, but shuttling regular humans around this century just doesn’t make sense.
Going to the moon was a fantasy at one point. I just don’t see any downsides to trying to become multi-planetary. Even if it fails there would still be technology developed in pursuit of that goal that helps life on earth.
There is a big difference between a scientific mission and a self sustaining presence.
The later is still so far off that, as was said, other technological “paths” are decades, if not centuries, closer. If we survive on Earth that long.
What I am getting at is that viewing Mars colonization as a means to preserve human life is absolutely nuts. It’s literally impossible in a reasonable timeframe, even with speculative technology/engineering, without changing humanity to the point that the whole fantasy changes anyway.
