It is less energy to go Mars to the moon than earth to the moon
Comment on A City on Mars: Reality kills space settlement dreams
Draegur@lemm.ee 11 months ago
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.
bluGill@kbin.social 11 months ago
PersnickityPenguin@lemm.ee 11 months ago
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.
guitarsarereal@sh.itjust.works 11 months ago
Once there’s a fully space-based supply chain up and running using materials from the asteroid belt, I strongly question the utility of a Moon colony. Any resource you could find on the Moon that would be necessary to get us out there would also be available in the asteroid belt, and once there’s a pipeline of extraction, processing, and manufacturing in space, there’d be no reason to make an extra stop on the SURFACE of the Moon except to drop off resources for people already living there. It’d be an economic atavism at that point.
Now, using planets and moons for their gravity to park space stations and perform slingshot-type maneuvers, that makes a lot of sense. But we’re all still so stuck in our 20th century imaginations of space colonization being like, idk, settling the Plains but on Mars we can’t think through what a space-based economy would actually look like.
The book’s exploration of what cIty oN mArS would look like is insipid at best. If people settled Mars for some insane reason, it would look like the Expanse – miserable, desperate, nobody lives on the surface, and as soon as the space based economy hits a certain point of development it would be entirely pointless.
Why tf would you figure out how to cope with Lunar and Martian regolith when you could just… not?
CherenkovBlue@iusearchlinux.fyi 11 months ago
Gravity is kind of necessary for long term human health though, at least until we figure out a way around that…
ItsMeSpez@lemmy.world 11 months ago
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.
bluGill@kbin.social 11 months ago
Do those count for gravity ? Are there other downsides that we haven't even thought of? Many unknowns.
AA5B@lemmy.world 11 months ago
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
guitarsarereal@sh.itjust.works 11 months ago
Settlers routinely sacrifice their health to be part of the first wave of people to stake a claim on fresh territories, considering how insane that got during more or less every colonization effort in past history I strongly doubt that harming human health will be a barrier to the whole thing, for better or worse. (I think mostly for worse tbqh, but I still see it happening unless climate change ruins everything, or nuclear war, etc)
c0mbatbag3l@lemmy.world 11 months ago
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.
guitarsarereal@sh.itjust.works 11 months ago
Yeah, but the point is that if you want the real-world equivalent to the habitable worlds opened up by the protomolecule as regards Mars, that’s actually just the entire rest of the outer solar system, especially the moons and asteroid belt. They’re exactly as habitable as Mars will ever be in actual reality. Mars stops mattering except as an orbital pitstop as soon as there are places that are just as good if not better developed farther out, in smaller or non-existent gravity wells.
Mars has no active geology, therefore no Van Allen belts, therefore the only shielding you get is if you bury yourself. And to generate the energy required to artificially generate Van Allen belts that can actually protect us from cosmic rays… first, it’s a preposterous amount, second, it’s energy rent you have to pay in perpetuity to get an inferior environment anyways and zero resources that aren’t available in greater abundance in cheaper gravity wells, because you’re not realistically going to be spinning up the core anytime soon.
Then there’s the 38% Earth gravity, which A - is likely to be as unhealthy as a spun-up semi-microgravity environment B - isn’t strong enough to retain any atmosphere thick enough to support humans, which means not only do you have to pay a continuous gargantuan energy rent just to one day walk on the surface, you also have to import atmosphere which you’re guaranteed to have to replace.
I enjoy the Expanse, but in spite of its hard science reputation it’s honestly about as realistic as Star Trek in a lot of ways. Terraforming Mars is a fun thought experiment but Jules Verne level out of date at this point.
SkyeStarfall@lemmy.blahaj.zone 11 months ago
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.
ItsMeSpez@lemmy.world 11 months ago
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).
SkyeStarfall@lemmy.blahaj.zone 11 months ago
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.