O'Neill Colonies (L5)

Discussion in 'Science and Technology' started by Mysterion, Jul 10, 2020.

  1. Mysterion

    Mysterion Vice Admiral Admiral

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    45 years ago this month Dr. Gerard O'Neill testified to congress on his proposals for our future in space, presenting his ideas for manufacturing in space, solar power satellites, and free-space habitats a the L5 point in Earth-Moon space. This was big stuff at the time amongst those of us interested in space travel, but seems to have faded into the background these days. I think these ideas need to be brought back to the forefront and given another look.

    A video about the Bernal Sphere type of colony:


    Here's a good video talking about the O'Neill Cylinder type of colony:


    And here's a link for a page with a lot of resources if you want to dig deeper: https://space.nss.org/settlement/nasa/

    Why schlep out of our own gravity well and go all the way to Mars just to climb down into another gravity well that'll need to be terraformed? Why not just build a bit more locally without the hassle of gravity?
     
    Last edited: Jul 10, 2020
  2. XCV330

    XCV330 Premium Member

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    Fascinating interview between O'Neill and Asimov

     
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  3. Asbo Zaprudder

    Asbo Zaprudder Vice Admiral Admiral

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    The Babylon stations on Babylon 5, the station in Elysium, and the Glitter Band in the Revelation Space series by Alastair Reynolds are basically O'Neill colonies. There are many other examples in SF. The main problems we have in building such structures are a lack of motivation, the capital expense of seeding sufficient construction infrastructure in orbit and beyond, and the high risk and lack of quick return on investment. I expect it'll happen eventually...
     
  4. Santaman

    Santaman Vice Admiral Admiral

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    ^^ I agree, human stupidity and greed prevents us from building these, I hope they get going with them soon, I'd like to get of this planet ASAP..
     
  5. valkyrie013

    valkyrie013 Fleet Captain Fleet Captain

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    Gundam uses O'Neill colonies, and various other versions in its shows, to the point that Half the population is in space colonies at all the Lagrange points.
    They even do a "Colony Drop" using a 20 mile long version.. needless to say it evaporates Sydney.. Poor Aussies..
     
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  6. XCV330

    XCV330 Premium Member

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    one variant of the O'Neill cylinder I think is very promising in a more reasonable space of time is the Kalpana One Settlement. It could be thought of as something between a Cylinder and the Stanford torus, essentially a truncated cylinder. It has more of a focus on radiation and micrometeorite shielding, to that effect it has no windows, with sunlight safely piped and can be given an Earth day/night cycle.

    Following O'Neill's ideas most of its mass would still be built from lunar materials sent to the construction by mass driver. The immediate form could be inflated.

    https://spacehabs.com/space-stations/kalpana-one/

     
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  7. Santaman

    Santaman Vice Admiral Admiral

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    Not sure but would a Stanfor torus be quite a bit smaller than a O'Neil cylinder?
    https://en.wikipedia.org/wiki/Stanford_torus
    Seems like a good way to get into the habitat game.
    https://en.wikipedia.org/wiki/O'Neill_cylinder
    And indeed these are larger...

    Personally I'd find an asteroid with about the right diameter, have it rotate and hollow it out to get a space habitat, you'd get the radiation shield and raw materials for free and on location, of course it would have to be a nickel/iron asteroid..
     
  8. valkyrie013

    valkyrie013 Fleet Captain Fleet Captain

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    Read that one theory was that they'd take an asteroid of the proper size, melt the interior, then introduce air in to it then blow it up like a baloon, and then you'd have a perfect circle to habitate.

    O'Neill found out that for best stabilization, that the colony's would be needed in pairs.
     
    Last edited: Jul 11, 2020
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  9. Christopher

    Christopher Writer Admiral

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    Babylon 5 is more of a Bernal sphere, while Elysium is a Stanford torus. The Glitter Band is an assortment of thousands of different space habitats, presumably of multiple different designs. The term "O'Neill cylinder" refers specifically to a large cylindrical habitat, not a spherical or toroidal one.



    I think I read somewhere recently that that wouldn't work well because the asteroid material would be too brittle. I don't remember where, though.
     
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  10. XCV330

    XCV330 Premium Member

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    It's smaller but uses a lot of material. Probably not as much material, however. My copy of High Frontier is stuck on a dead kindle at the moment.

    Both the Stanford Torus and the O'Neill Cylinder experience wobble that has to be addressed.

    But the torus has advantages. It does not have a spinning mirror. The mirror can be made in segments and put together. O'Neill Cylinders large rotating mirrors are a big problem in the design. they will be subject to higher gravity than the rest of the cylinder, so sheer and metal fatigue of the supporting structure if a potential problem. For any of the mirrors repair is just going to be a jobs program that never ends. It's like the people assigned to repaint the Eiffel Tower. they never actually stop repainting it. It's just a multigenerational job.
     
  11. Christopher

    Christopher Writer Admiral

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    Would counterrotating pairs help? That's generally necessary to allow precession (to keep the mirrors pointed at the Sun throughout the orbit) by cancelling out angular momentum.


    That's what robots are for. Also self-repairing smart materials. It's the future, don't ya know.
     
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  12. CorporalCaptain

    CorporalCaptain Fleet Admiral Admiral

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    Wikipedia isn't 100% accurate, of course, but the article at https://en.wikipedia.org/wiki/Babylon_5#Setting says:

    The Babylon 5 space station is located in the Epsilon Eridani system, at the fifth Lagrangian point between the fictional planet Epsilon III and its moon.[6] It is an O'Neill cylinder 5 miles (8.0 km) long and 0.5–1.0 mile (0.80–1.61 km) in diameter.​

     
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  13. XCV330

    XCV330 Premium Member

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    Yes, pairing removes that problem, as far as I know. The problem is that angular momentum upon one of the axes will change little by little over time, and that effect will compound without active control to stop it. This is no minor bit of stationkeeping on a rotating cylinder the size of Island One. (Bernal Spheres are stable, however). Pairing them removes the wobble but requires an extra cylinder and more than doubles the complexity. And there are still those mirrors swinging around at 2.5G pseudo gravity at the edges.

    The Stanford torus has some stability issues, and requires a truly massive mirror, but is easier to shield for radiation than the O'neill cylinder. One thing I think O'Neil was a little too optimistic about was radiation shielding. I think he felt that pregnant women and children could just be whisked away for awhile, or the families would take a break from space life for a few years at best to compensate (Again, don't have my copy in front of me). That may be so, but it sets up an entire culture path that is not really desirable for most people who might want to move to a space settlement, or even economically feasible.

    Likewise I don't think the population would want to treat every solar flare event like a Cold War bomb drill in school. Yes I remember those.

    One reason I like Kalpana One is it addresses the issue of radiation head on. It's not as majestic as the 1970's designs but it uses the best of what they can give in a "What could we do now if we really wanted to make this happen" kind of way.
     
  14. Christopher

    Christopher Writer Admiral

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    There's an alternative approach, a windowless design that uses fiber optics to "pipe" sunlight in:

    https://www.dyarstraights.com/gundam-test/how-the-other-half-lives/

    And of course there's the option of purely artificial light -- better for greater distances from the Sun, or for interstellar habitats like the Chirrn nations in my story "Aggravated Vehicular Genocide" and its soon-to-be-released novel expansion Arachne's Crime.

    As for radiation shielding, you could generate a magnetic field around a space habitat much like the one around the Earth. That would still leave ionizing EM radiation, though, but there are some promising advances in lightweight shielding materials, like metal foams.
     
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  15. XCV330

    XCV330 Premium Member

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    It's cool that technical advances they had not had on the horizon a few decades ago can make help these things occur hopefully one day. First stop, the moon.
     
  16. valkyrie013

    valkyrie013 Fleet Captain Fleet Captain

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    Yeah, gundam, universal century version, has both open type, ( mirror and windows) and closed type ( no mirror, internal light tube, probably directed sunlight for the tube)
    Stanford torus a few times as well.
    Other series had variations.
    I would think that the hull would be thick enough or maybe a lead or water layer would help. Though I have zero idea on absorption of materials.
    Also would think they'd have shelters for harsh storms.

    Seen one documentary of using an Oniell type for a space ark. ( and interstellar, though it looked like one end cap was the light source) Though they'd have both acceleration gravity and centrifugal, which only works on ships that can tilt there spiking parts like a pilgram craft.
     
  17. XCV330

    XCV330 Premium Member

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    One end cap could work if the light was reflected back through an interior mirror at the opposite end, perhaps I dont think they showed all the angles of that station. wish we could have seen more but i was happy we saw something.

    the Nauvoo/Meridian Station in The Expanse is partly a large cylinder. i don't think it has windows.
     
  18. publiusr

    publiusr Vice Admiral Admiral

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    You and me both
     
  19. Asbo Zaprudder

    Asbo Zaprudder Vice Admiral Admiral

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    Perhaps one could use a general term such as space habitats for large structures that are designed for long-term sustainable inhabitation in orbital free fall. One could then debate which of the many possible designs for such habitats would be most optimal to construct and maintain and would provide the best return on investment. Any such habitat would require a common set of technologies and infrastructure to be developed for resource extraction, processing, and transportation and for construction without relying on matter hefted out of Earth's gravity well - apart from any necessary seed infrastructure. As a species, we haven't yet progressed in the direction that is required beyond talking about it.
     
  20. Christopher

    Christopher Writer Admiral

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    If it's a generation ship, or a habitat meant to drift permanently in interstellar space like Chirrn habitats rather than thrusting toward a specific destination, then the acceleration along the axis can be very gentle. A sustained, low acceleration can still build up over time to a significant velocity. You don't build a generation ship if you're impatient.