“Long-term colonization of the solar system with 290,000 square feet per person”

That’s a lot of room.

“…A 5 km settlement radius corresponds roughly to the sweet design spot where earthlike radiation shielding is produced for free by the required structural mass…”

https://www.nextbigfuture.com/2018/09/long-term-colonization-of-the-solar-system-with-290000-square-feet-per-person.html

Here’s another good one.

http://space.nss.org/kalpana-one-space-settlement/

Here’s a link describing super cheap material launch from the Moon with rail guns to Mars. Could be to Earth orbit also.

I’ll add that with a solar concentration mirror and some separation of lunar materials we could build 3D parts out of Moon dust then launched. Large things could be launched as long as you got the center of gravity right. Maybe with slower acceleration. All this stuff could be built with a solar powered remote controlled rover with arms and manipulators. Machine tools could be built from scratch. The key is to take your time and build from scratch. I wonder how you could build amplifiers, switches or semiconductors from lunar soil? Surely must be a way. Maybe use magnetic amplifiers instead of transistors or CMOS type devices.

Sam says, with a mischievous twinkle in his eye,”Yes really.” :)

“…In space, you need to provide a lot more radiation shielding and spin the habitat for gravity Mars as it is today is an easier place to build such habitats, …”

Mars has little atmosphere for shielding so…you have to dig up habitat anyways. What difference if what you dig up you dig up from the Moon, on Mars or an asteroid??? Still have to dig and crush it. Move it.

“…particularly given the abundance of different resources available…”

No resources in Space???? Where you going to get your terraforming atmosphere??? Massive resources in space on low gravity floating rocks of any sort you want.

“…It’s far more expensive to create farmland in space than it would be on a Mars with a ~100mb CO2 atmosphere…”

Not seeing it. Mars is damn near a vacuum as far as unsuited humans are concerned. Any attempt to rehab the whole planet would take an extraordinary amount of material and energy. Instead of spreading it out on the “thin” surface of a planet you could take the exact same material and make mega earth surface areas in free floating multiple habitats. The whole reason for moving to space, in my opinion, is to have a civilization back up to the Earth if it gets whacked by a big enough rock, solar flare, close by supernova, etc and use the massive resources in space.

The big failure of Mars is it has a gravity field. A total waste. Anything going up or down must use energy and materials to no end at all. Spinning a habitat cost…next to nothing. The energy required for habitats could be far, far less. The delta V from the asteroid belt and the Moon is not that great. There’s a lot of work already done on using Moon material and mass drivers to launch it to where it’s needed. It’s so much cheaper to free float habitats in space that Mars habitats are not even in the same ball park.

Solar power would be way cheaper in space. At Mars all that damn dust and supports and way less sunlight means you really should use nuclear power. Well if you’re going to that you can still do it cheaper in space. Mars is a high gravity suck hole.

Look I like planets but in actuality we’re talking about energy cost and what it takes to move humans into space. If it cost too much or takes too much up front money it will never happen. Maybe Mars will be terraformed some day but I bet it won’t. I would bet it would be dismantled for logic gates that humans, or the silicon life that overthrows us, needs before so much as one load of gas is sent there. I mean a planet???. Silicon life needs no damn planet and those that refuse silicon transcendence will just stay on Earth like the Amish.

https://www.youtube.com/watch?v=V_02EXoIbn8

https://en.wikipedia.org/wiki/Bishop_Ring_(habitat)

https://en.wikipedia.org/wiki/Space_habitat

I think that trying to speculate about what’s going to be the “easier/more likely” path to colonizing off-Earth living spaces is extremely premature. We don’t even know what we don’t know, to be honest.

Yeah, artificial habitats might not be economical, but what about the problems with moon dust and the Martian perchlorate deposits? Keeping that crap out of the environments we try to build on either the Moon or Mars may actually be unaffordable, in terms of long-term viability. If you think silicosis is hard to deal with on Earth, then try it in a low-gravity vacuum environment. The early settlers are going to have a lot of very complicated issues to deal with, many of which are not even foreseeable to us at this time.

The other thing to consider in all of this is the psychological aspect–If you know guys and girls who do things like sailing small craft on long ocean voyages, you’ll note a certain difference between them and their land-borne compatriots. The ones who actually survived that sort of thing, back before satnav and easy access to rescue?

All of the ones I’ve known were anally-retentive detail freaks with extreme OCD for things like “Did I shut that hatch? Is the porthole open…? Did I buy the flour at the last stop…?”.

Friend of the family did a bunch of solo cruises back during the 1960s, one of which was a cross-Pacific voyage. I don’t know if the guy I knew did those voyages because he had those traits, or if he developed them sailing alone, but… He had those tics, for life. Dude could not go to a store and just buy something–He had to have a list, and a well-thought out reason. No plan? No action… Zero spontaneity.

You also find that same sort of psychological effect in guys who do cave diving and other such sports. From this, I think we can reliably predict that anyone who lives in an unforgiving environment like deep space is going to exhibit similar traits, and that the societies made up of people like that are going to be… Different. Very, very different. Japanese may do well, given that they are already used to the high-cohesion and socially conformist requirements that living in a deep-space environment will likely have.

Arabs? LOL… Islam in general? Any relatively primitive and low-social trust society? Ain’t going to happen. All it’s going to take is one guy in the habitat getting greedy and saying “Screw my buddy…”, and everyone there suffers or dies. People prone to that behavior are probably going to wind up going straight out an airlock for things like failing to recharge an emergency air supply after using it. Many generations of this, and you’re going to have a very different culture and society. It may even produce identifiable biological effects stemming from selection for specific behavior sets.

Not really. In space, you need to provide a lot more radiation shielding and spin the habitat for gravity. Mars as it is today is an easier place to build such habitats, particularly given the abundance of different resources available. A partially terraformed Mars, where farming can take place in unpressurised polytunnels, would be a lot easier than that. Most land humans use is used for growing plants, whether to eat directly or to feed to livestock. It’s far more expensive to create farmland in space than it would be on a Mars with a ~100mb CO₂ atmosphere.

I have the opinion that there’s going to be a lot more to this whole question than we’re really even aware of, and it may well be that we’re not going to be able to do it in any large-scale or effective manner, without exponential increase in both our knowledge and capabilities.

Hell, I wouldn’t necessarily rule out that the whole thing is going to require transfer of consciousness to electro-mechanical surrogates, either. We may only get off of Mother Earth as disembodied electronic ghosts.

I say there’s little to no difference to being forced to live in tunnels on the Moon or Mars and living in a Habitat in space. The Habitat would seem more roomy. To bad we don’t have some of that “Ring World” stuff to make Habitats out of.

1) Would it be possible to use one or more other gases instead of Nitrogen?

2) Even if an atmosphere is created, wouldnt the lack of a substantial moon (phobos and demios arent big) mean that the weather system would be extreme. No moon means no tides means no circulation of water.

3) Why has no one thought of Venus as a potential planet for terraforming? Or is removing/modifyog an atmosphere more problematic thsn creating one?

According to NASA, the loss to the solar wind is significantly less than the gain from outgassing (as I calculate here – http://newmars.com/forums/viewtopic.php?pid=148825#p148825). Which means that something else is keeping the atmosphere at it’s low level. It’s probably no accident that it hovers around the triple point of water.

We don’t need to make the atmosphere Earth-like for it to be very useful. A ~100mb CO2 atmosphere would provide much more radiation shielding and, importantly, enable farming to occur in lightweight unpressurized polytunnels. Far cheaper than the greenhouses we’d need with today’s Mars – or the complex arrangements we’d need for in-space colonies. At that point in terraforming, there should be some liquid water as well, and the possibility of genetically engineered plants growing on the surface and putting out oxygen which can be easily distilled from the atmosphere.