On planetary surfaces, in contrast, you face the very real problem that raw materials you can find may be located at a considerable distance from your habitation. We have oceans on Earth to make long-distance bulk transport economical, but we won’t have that anywhere else. Building a large road or rail network on Mars to move stuff around looks to have a poor expense to reward ratio too, at least in the early going. The only other alternative is using point-to-point sub-orbital rockets to move things over long distances. That hardly economizes on delta-V. I still think mudballs are not where we need to be going except for researchers and people who fancy doing a feet-and-footprints publicity thing.

Sorry for being terse and obtuse. I will now be more explicit.

Keep in mind the quote that from earth to orbit is about half the delta v to anywhere. So yes, getting to and from orbit gobbles up lot’s of delta V, but less than half for those smaller than earth.

But here’s the deal… Launch is much closer to a one time deal per person once you get to a mudball because you stay there. In space you also may stay there, but you still have to pay the other half of delta V continuously for required resources. A mudball that you don’t have to leave for resources has a huge economic advantage. An advantage that space habitats will take over a hundred of years to equal. Mars can be self sufficient almost immediately and will have Walmart in a couple of decades.

A charter with terms that legally establish property rights by possession enforced by it’s members to limit supply based on rate of colony growth will allow an ownership society to demonstrate it’s clear superiority to the usual slavery plan being espoused by almost all others. That cargo cult mentality won’t work, but it dominates the thinking. What happened to individual risk and reward?

another possible obstacle to Mars colonisation

Why would it be? It’s regional. Let somebody explore the area when they get around to it.

In space, almost all of your resources are someplace else. The rocket equation is a huge drag on such an economy. In time we will build up to it. Until then, mudballs are far from obsolete.

Terraforming an entire world is mega-engineering not yet ready. We need to think in terms of how we terraform right here on earth… by habitat and by community.

One of Travis S. Taylor’s biggest objections in his book A New American Space Plan is how NASA keeps developing a technology, then abandoning it to start something new. Part of it is politically driven — a new administration doing the Not Invented Here thing and ditching a predecessor’s program because it’s the Other Guy’s Program. But I’m wondering if a big part of this inability to pick a plan and stick with it, especially related to Constellation and then SLS, is that each of them reach a point where they’re no longer Bright And Shiny, but clearly are going into a valley that looks like a retreat (politically untenable, especially in a political climate driven by the four-year election cycle).

A lot of people in the Alternate History communities have speculated that if only the Soviet Union hadn’t thrown in the towel on their crewed lunar program after Apollo 8, we might have stayed the course instead of retreating back to LEO for the past four decades. So maybe a serious Chinese space race might actually get us back on course, if they can sustain their program enough to maintain the push until both (or all) sides have a sufficient space presence that there’s no way it can be shut down by a shift of the political winds after an election.

Perhaps even sooner. When I read your post, this is what came to mind. Imagine a giant lathe. Put a Bigelow-style balloon cylinder in the center of the spindels and rotate very slowly. Using 3D printer style technology, slowly start applying an outer surface to the balloon cylinder. The material deposited could possibly be as low-tech as concrete made from asteroid materials. Build up your outer shell over a period of days, weeks, months to include areas for water storage (which would double as radiation shielding), then cover the outside with solar cells for electricity. Once the shell is finished, you can being fitting out the interior to meet your needs. The limiting factors would be the size of your lathe/printer assembly and the rate you can supply asteroid materials to it. What can be made in space must be made in space from materials that are already in space. Only those things that aren’t (yet) possible to make in space (such as integrated circuits) would be launched from the Earth.

Maybe Mars could be terraformed, but it’s about the only place in the Solar System that looks like an even marginally feasible prospect for such a project. And why bother? Planetary re-engineering is complex, expensive, risky and time-consuming. For a lot less money, risk and time, you could create far more usable real estate by converting the Asteroid Belt into O’Neill colonies. If you need more mass, or want to tap conveniently concentrated stores of some particular element or compound – water ice from Europa, sulphur from Io, or methane from Titan, say – use a tiny bit of the carbon in the carbonaceous chondrite rocks to make carbon nanotube cables, then fabricate beanstalks to allow economical access to the surfaces of moons and minor planets. Or even Mars.

And I don’t get your comment about delta-V at all. Getting onto and off of large planets is what gobbles up delta-V. Orbit changes within the Asteroid Belt are trivial by comparison. Want to be spacefaring and still minimize your delta-V footprint? Live in free space, not on mudballs.

As for the question of scale, I wasn’t implying a one-size fits all space structure future. The O’Neill reference was just to underline the fundamentally different goals of living in free space as opposed to seeking out other, and inferior, planetary surfaces. An irrational attachment to mudballs makes no sense because, as Ken points out, they don’t love us back and are quite able to indifferently kill us. In the United States we have clusters of skyscrapers in major cities, isolated hunting cabins in Montana and Northern Michigan and everything in between. I see no reason to suppose space will be any different. Form, including size, will follow function.