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A City on Mars: Reality kills space settlement dreams
(arstechnica.com)
This is a most excellent place for technology news and articles.
i mean shoot, mars is actually kinda worse than the moon in some ways. Like, the worst of both worlds except 'worlds' pertains to 'celestial bodies in general'. You have the same ultrafine toxic razor sharp dust that gets everywhere, sticks to everything, and destroys mechanical joints on contact, but on MARS it gets blown around by dust storms that blot out the entire sky sometimes for months or years on end, whereas on the moon it only redistributes and resettles due to electrostatic repulsion (due to solar radiation).
Mars' atmosphere is just thick enough to be a hassle for creating risk of burning up on reentry but still too thin to reliably drag-brake so you end up having to thread a much more annoying needle with respect to approach velocity, whereas on the moon it's just straight up active thrust descent every time you're landing.
In both cases, living on the surface is a sucker's game and the only viable option would be to tunnel down beneath into the regolith where a sufficient rock barrier will block enough of the solar and cosmic radiation to not drastically shorten your lifespan.
Furthermore the energy cost to get a payload from earth to mars is LITERALLY ASTRONOMICAL whereas escaping the moon's relatively weak gravity well to reach almost anywhere else in the solar system (including mars) is dwarfed by the oomph it takes to climb out of the earth's gravity well in the first place alone.
I'd go so far as to say that a mars colony would never be viable until and unless we have a viable lunar colony
but make no mistake, a lunar colony is mandatory if we ever want to explore the rest of the solar system or not have all our eggs in one basket as a species. the moon is practically MADE OF the infrastructure we'll need across the entire solar system,some assembly required. The amount of Aluminum and Silver waiting for us in that silicate regolith will be instrumental, especially because smelting and building up there will be drastically cheaper than manufacturing shit down here and then having to carry it ALL THE WAY UP ALL OVER AGAIN.
and like, that isn't even factoring sending any of what's produced back to earth, because even that might be a waste of effort when everything we could ever BUILD outside our gravity well is worth more being up there just by virtue of the fact that we didn't have to pay through the nose to SEND IT.
The most not caveat is we don’t know how much gravity is how necessary. We know that microgravity in orbit is too little and not really sustainable. Is gravity on the moon enough more for long term health? Is that on Mars? That’s just two of the questions we can’t know until we get there
So you build spinning space stations instead of settlements on the martian or lunar surface. Likely close to the same material cost, if not cheaper, while allowing us to actually choose the amount of gravity to generate. We don't know if martian or lunar gravity would even be sufficient to avoid negative health affects.
Do those count for gravity ? Are there other downsides that we haven't even thought of? Many unknowns.
You do realize that Martians abandon Mars because the protomolecule opens up worlds that are already habitable, so terra forming becomes pointless? It has nothing to do with infrastructure or economy, Mars is supposed to be an eventual second home, not a place to mine. They leave because interstellar travel becomes a reality before Mars becomes viable.
Unless we discover that Charon is actually a Mass Relay, Mars is the best possible second place for humans.
Titan is too cold and the atmosphere would require a full changeover, and the Galilean moons are constantly bombarded with radiation, Venus could support a floating colony but thats tenuous at best. Mars is basically it, if we can develop the tech to turn it into a reasonable place to be.
But gravity may be useful in many applications. We don't really know how to effectively manufacture many things in microgravity at the moment. The moon would still be important for early space infrastructure.
Edit: In addition, the moon will be useful for mining and resource extraction for a long time, most likely, due to its proximity to earth and size.
The gravity problem is also best solved away from the surface of any celestial bodies. Massive spinning space stations would be much more pleasant to live in in almost every way. Unless a planet or moon has a good reason to land on it (e.g. material to be mined) it makes much more sense to simply build a habitat away from the gravity well and build smaller work camps on the surface that can be supported by the main habitat(s).
The problem is that such space stations are very complex to build and maintain, and can more easily catastrophically fail. It's certainly an option, but it may not be worth it.
Of course, all of this is speculation, but my point is mostly that if we don't have sufficiently advanced space construction capabilities, surface habitats and infrastructure on the moon may be preferable.
It is less energy to go Mars to the moon than earth to the moon
It is also about the same delta-V to go from the surface if the earth to the surface of the Moon OR Mars. At least Mars has water.