Many of these pictures are based on designs described in one of my favorite books of all time, The High Frontier, by Gerard K. O'Neil.
In it, O'Neil, a Princeton physicist and founder of the Space Studies Institute, goes on to describe in great technical detail the feasibility of building artificial space habitats of varying sizes. I heartily recommend it to anyone even remotely interested in space. The ideas from this book have been implemented in countless fictional universes[1], so you may find that you've seen them before.
That featured strongly in my childhood imagination. I'm no longer the technotopian I was at the time, but it's a powerful vision. Much of what it (and O'Neil) promoted should have been done by now were it possible.
O'Neill clearly wanted it to happen and let it bias his estimates. But what bothered me the most was that even if you did follow their strategy of build-powersats-in-place-out-of-extraterrestrial-materials, you could do it cheaper with workers in tin cans (and lots of automation and teleoperation) instead of livable colonies. The argument against this wasn't too convincing, but I was a teenager and figured "Hey, a lot can happen in a few decades." A lot more than actually did so far, sigh.
I still think large-scale work could have been done in space, and wasn't more for societal than technical reasons.
I suspect the powersat evolved as a mission justification: so, we can conceive of human-habitable structures in space, but why would we do that. From Heppenheimer's book, it seems that the colony concept emerged first, then the powersat concept.
Once you've arrived at "orbiting solar power stations built from lunar regolith", questioning your premises and realizing that the colonies really don't make all that much sense. But then again, pragmatism and overt missions never really ruled space anyway -- see Apollo and the Shuttle.
As for the technical reasons, to paraphrase Douglas Adams: Space is expensive. Really expensive. You just won't believe how vastly, hugely, mindbogglingly expensive it is.
The ISS is the most expensive single structure ever constructed, and among the most expensive single projects ever undertaken -- and that for a habitation for six people. Total cost is somewhere north of $100 billion (how far north isn't clear, the budget's spread among multiple agencies and nations).
Given that, and absent tremendous gains in efficiency and automation, the cost of solar power satellites let alone O'Neil space colonies would be in the tens of trillions of dollars, minimum. That's on the scale of the entire US GDP, if not more.
As for your observation "a lot more than actually did [happen]": Colonies in Space is one of my benchmarks for rates of technological change that didn't happen. I'd anticipated that that could well be my future, but a decade and a half past when it was supposed to be a reality, it remains science fiction. It's given me a good sense of the sorts of change which are possible and likely, and those which aren't. And no, not all progress is subject to Kurzweil's Law of Accelerating Returns.
>> It's given me a good sense of the sorts of change which are possible and likely, and those which aren't. And no, not all progress is subject to Kurzweil's Law of Accelerating Returns.
Indeed, we may be in Vinge's "Age of failed dreams".
It hasn't been done already because launch is still crazy expensive. Now we've got SpaceX making solid progress towards a fully reusable launch vehicle, which should drop costs by an order of magnitude, and Planetary Resources working on near-earth asteroid mining.
They are both extremely difficult to accomplish with current technology. The issue with Mars is that it has no magnetosphere [1], and as such, all habitats will have to be underground and/or shielded with very thick layers of lead, dirt and water.
Man made colonies will have the same problem, in addition to requiring space manufacturing and assembly at a level that is currently impossible.
If SpaceX brings the cost of space flight down to its basic energy costs, we will have solved one problem. The other problem is the power generation required to conduct space manufacturing at a large scale. Solar, although consistent, is low in power density and thus requires large amounts of surface area that is very difficult to maintain in space.
Until we crack compact, high yield fusion, I doubt we will make much progress in realizing our space-faring dreams. This was also the opinion of the late Robert Bussard, inventor of the Bussard ramjet and the polywell fusor.
Mars colonies, at least, can rely on Nitrogen and CO2 from the Martian atmosphere. Orbital habitats have to import everything but sunlight.
Having the colonies underground may have an extra advantage, both on Mars and on the Moon, as they may be closer to sources of ice. I remember hearing something about the Moon being much less dry than previously thought. No running water nor blocks of ice, but maybe crunching rocks yields something useful.
Right on. To add to this, early stage terraforming is in the immediate rather than long-term plan for Mars. As soon as we start producing CO2 on Mars, we're on our way.
I'm not against colonizing space itself, but early seagoing explorers didn't attempt to colonize the ocean. We need to establish ourselves in environments that allow easy production of oxygen, water, and food.
In the end, it is about money. It takes a lot of money to get setup on Mars, but after it is setup, it is a HUGE resource, which means much, much more money. The moon could also be a huge resource, but it is expensive to colonize because it can't hold atmosphere easily. Colonizing space itself without mining a resource in a way that eventually will pay off the initial investment is useless and a drain on our society.
There is no reason to require the place to hold an atmosphere - you just need to build your colony underground (which you already have to do to protect it from radiation). The Moon may be interesting for magnetic launch systems (no atmosphere, plenty of energy and reduced propellant requirements) and all kinds of metallurgic processes (no atmosphere, low - but not too low - gravity). Mars is also interesting if you can industrialize the manufacture of fuel and oxidiser from the atmosphere - gravity is low enough you can make it into a chemical rocket fueling station (landers and such will still use chemicals for a long time), at least until we develop some icy moons further out.
But neither can Mars. Most of its early atmosphere was blown away and that will continue. There's nothing we can do about the lack of gravity.
The problem with Mars is that it is cold, terminally. The nuclear furnaces have gone out. I haven't seen a proposal from the terraformers that counteracts that. You might be able to counteract it with CO2, but then that gets blown away by the solar wind. It's crazy hard to fix.
Don't get me wrong, I would love to see us on Mars. Unfortunately, the engineering and science obstacles are huge, enormous.
> Unfortunately, the engineering and science obstacles are huge, enormous.
Yes, I agree we should go to Mars. I don't see the urgency, though. I mean, in terms of the humanity-backup situation, ten years or a hundred, doesn't really make much difference.
We would be better putting the money into energy research, and when we've got that figured out, then we tackle mars.
Projections that there's enough uranium for 200 years[1] are based on levels of present utilization: around 3.7% of global energy use[2]. Bump that to 100% and we'd run through all available reserves in less than a decade (7.4 years, if you're counting).
Solar energy (including solar mediated via plants, wind, or water), hydrogen fusion, possibly geothermal energy, or with really long odds: hydrocarbon prospecting from another body (say, maybe Titan) are the only energy sources which could last a considerable human population for the possible maximum lifetime of the species.
Yes, a small Mars outpost could be powered off of nuclear power for a considerable period, but that would take away from available nuclear fuel supplies on Earth.
The likelihood of managing usable sustainable fusion under terrestrial or other contained circumstances are fairly unlikely IMO.
The fuel supply for conventional reactors is limited because they rely on U235, which is 0.7% of uranium. Fast reactors could use the rest of the uranium. That multiplies the supply by more than 100x because it means you can economically retrieve fuel from lower-grade ore, or even from seawater, which would extend the supply to millions of years. Russia has several fast reactors in production right now, and is building more.
Liquid thorium reactors are another option. There's no thorium in seawater, but on land there's several times as much thorium as U238, and it's all the same, useful isotope. China has an aggressive R&D program hoping to get a prototype reactor ready in a decade.
But personally I think it's likely that we will achieve sustainable fusion in the fairly near future.
My understanding of seawater is that uranium concentrations are 0.01 - 0.02%, and that it's not thermodynamically feasible to extract it for energy at those concentrations.
...which says that EROI is 22 assuming a conventional reactor. Ie., we'd get 22 times as much energy out as we spent on extraction. With a fast reactor the ratio would be a hundred times better, since we could use all that uranium instead of 0.7% of it.
Also, geological processes bring more uranium to the surface, and rivers are constantly putting more uranium in the oceans, at a rate that would provide 25 times our current electricity usage. If we keep our usage at that level, uranium will last until the sun goes out.
That's only proven reserves, though. Thorium right now is in basically no demand. Given the extremely high energy density of the fuel, A LOT of ores will become economically extractable.
It might not be 64ky, but >1ky seems to be very realistic.
i personally like painting/drawing over 3d rendering. There is something dull about the latest. I dont mind flawed or imperfect perspective for instance. It gives life to a painting.
Maybe, but we are still stockpiling weapons that can destroy our whole civilization at any time. It's not because we are currently in a relatively peaceful era that it's going to last in the long term.
Except that it's _not_ "uphill" in a force sense, since the attraction is the result of centripetal force, acting outward perpendicular to the ring at any point, not gravity, which would focus in toward a center.
I genuinely love HN for bits like this...both with an amusing quip, and then someone who can explain that technically, the amusing quip is inaccurate. It nicely stimulates both left and right side of my brain.
I remember some of these, which were reprinted in magazines like Odyssey (and maybe even Omni?) in the 70s and 80s. The images, along with colony/exploration books by Larry Niven, Ben Bova, and James P. Hogan, really had the power to set one's imagination on fire.
I was so thrilled the first time I saw Babylon 5's cylinder designed. 2001's toroid design was indeed iconic, but it kind of anchored the idea of what a space station should like for several decades!
The cylindrical colony is basically Arthur C Clarke's Rama. One of the images of the spherical colony shows a human-powered vehicle, which IIRC featured in the first Rama book.
On a much larger scale there is Ringworld, which incorporated a Dyson Ring, which is a variation on a Dyson Sphere[1], which was apparently inspired by a 1937 novel (according to the Wikipedia link).
In it, O'Neil, a Princeton physicist and founder of the Space Studies Institute, goes on to describe in great technical detail the feasibility of building artificial space habitats of varying sizes. I heartily recommend it to anyone even remotely interested in space. The ideas from this book have been implemented in countless fictional universes[1], so you may find that you've seen them before.
It all started here in this excellent book.
1. http://gundam.wikia.com/wiki/Space_colony_(UC)