Race to Kilometer Scale Space Construction

25 thoughts on “Race to Kilometer Scale Space Construction”

1. My proposal is to dig a hole on the Moon, put a cap on it with an optical port, and take advantage of the lack of atmosphere to use mirrors to focus sunlight in through that port.

   You can protect the port from contamination by introducing clean gas around it. The gas then flushes everything that's volatilized out, which will then fractionally separate as the gas cools. Once it's all condensed out or been otherwise separated, the gas goes back in.

   Gravity keeps the molten mass at the bottom of the hole.

2. I'd say this stuff is transitional to structures built with lunar, or asteroidial materials. These techniques could yield a deployable concentrating mirror to smelt extraterrestrial materials. I've speculated for a long time that in orbit, one could fractionally distill everything, up to tungsten, and carbon. With vacuum as a crucible, you can vaporize anything. The only problem is keeping the solids, and liquids in the focus while the gasses are boiling out of them. Maybe ultrasonics?

3. Mars isn't even a detour. The concept of "detour" isn't applicable if you're capable of doing more than one thing at a time.

   That's the point I'm continually arguing with Dan: We don't all have to do the same thing. Once we have affordable access to space, we can each do our own thing. O'Neill colonies will get built if they make economic sense, even if Musk goes to Mars, even if somebody else colonizes Lunar lava tubes. Heck, you'd get an O'Neill colony for the Mars colony shipyard workers to live in!

   Economics will dictate whether SPS in Geo or Criswell happen, or maybe one then the other.

   Affordable access to space opens the door to ALL these choices, and Musk isn't going to turn down customers just because they want to do something other than colonize Mars.

   It doesn't even matter that Musk doesn't think space power is a good idea; He's not going to refuse to cash your check if you pay him to put a prototype in orbit!

4. "build a big reusable rocket that makes such conceits moot." What do you mean by big? We need 20-200 TWe now, for starters. The only thing that *big* means in O'Neill thinking is whether you have rockets *big* enuf to send some crew, to help set up stuff. After that size is reached, which we have had all along, the steps are the same, leading to Space. If you actually do have a big rocket, send up an Avalon Settlement now! Otherwise, sending product rather than factories and mining equipment for product is "spinning your wheels". Remember, Mars is too tiny to matter at all in O'Neill thinking.

5. Glad you brought up Musk! I was thinking about the various plans for the HALO Gateway ISMRU O'Neill facility. This is where the rubber meets the road, right now. Are we paying Musk for repeated landings on the Moon surface, to practice for Mars, each supported by multiple launches of O2 from the Earth surface? Then, on to Mars, leaving no useful infrastructure? Soundz just like Mars First/Direct/Only plan, back from the grave. Or will we pay Musk to start bringing rego to ISM HALO Gateway for processing, or equipment to do that, so that refuel and helping the Earth are advanced. He can have the waste O2. To escape, without helping the Earth. edit: "Is the surface of a planet the right place""To escape, without helping the Earth."?

6. Yes, "easy enough" that has been clear from the start. We have spent decades trying to see if micr0g human life is *possible* (it is), but that is not essential knowledge for practical O'Neill work. A distraction caused by Mars, but certainly useful info nonetheless. K T designed a long cyl with spin about center, not long axis. Works!

7. sounds like a business opportunity to me..

8. perhaps not approved, but moved along incrementally through a recognized design process…

9. Eh, this is just entry level work for building the 1km+ transmitter of a chinese branded GEO SPS, which is being worked on by the Bishan facility that had a recent article about construction work recommencing at the site to finish it. It seems some more budget has recently befallen the SPS/space infrastructure guys in chinese aerospace recently after a 5 year lack of funds (possible fallout from a lowered priority in the regular chinese government 5 year plan pushes previously?)

   I would note that Brian failed to mention that despite Tethers Unlimited Inc.'s apparent headstart with their SpiderFab work, Made in Space's Archinaut is the one that will have a practical flight demo soon, though as simple truss maker flight demo.

10. That's interesting, but given that a starter spin gravity habitat should probably be a bolo style, making it big enough to lower the RPM to the point where there wouldn't be even initial discomfort seems easy enough.

    It's not like you need the habitat to start out as a complete ring or cylinder.

11. The time for O'Neill cylinders is coming and people can dream of them again, but the detour to Mars isn't on the negotiation table. It's Musk money and he who pays the piper calls the tune.

    Musk simply wants to see humanity become multiplanetary before his own passing. Whatever humanity does with his rockets besides that is gravy.

12. O'Neill made plans with Shuttle *as promised*, so now we are getting that sort of capability. But the basic idea is the same, no reason to delay further decades. Forget Mars!

13. One would lose control of the situation if things could be made in Space, from Space materials. Power addicts recoil in terror at the thot, so they cannot think it. The self humiliation of the biggie socialist state continues. Do they have any clue?

14. Nothing prevents us from having both a wide road from Earth to space and developing sustainable ISRU on space, in fact one probably begets the other.

15. The DARPA NOM4D proposal is based upon the notion that 3D printing with Earth launched stock material will be 1/10th as massive as launched pre-built structures for same result, practically. So, 1/10 the launch. Then, simple to add lunar or asteroid material as avail. O'Neill micr0g factories, finally!

16. This is painfully gimmicky. Sure, the resulting structure will be huge, but it will have little in the way of structural integrity, and won't be beach ball tight, let alone air tight.

    Just ship up raw materials until we can manufacture them from space resources, together with the machinery to transform them into decent structures.

    And if you need something huge and gauzy, there are probably better ways to do that, too, than this over-sized children's toy.

17. See DARPA NOM4D too.

    "it appears that the lower limit of space settlement size is not determined by human response to rotation rate but rather by other factors. This means that the effort necessary to build the first space settlements may be significantly less than previously believed, simply because they can be much smaller than heretofore expected."

    https://space.nss.org/wp-content/uploads/NSS-JOURNAL-Space-Settlement-Population-Rotation-Tolerance.pdf

    https://www.bis-space.com/membership/jbis/2019/JBIS-v72-no09-September-October-2019%20-%20Subscription%20Copy.pdf

18. Until the supply on Earth runs short. The reason to do ISMRU is only partly to avoid launch costs. This basic situation has not changed since first pointed out by O'Neill long ago. Cheaper rockets mean quicker O'Neill, that's about all.

19. woah. woah. resurrection not. Inflatable habitats are robust and ongoing. B.E.A.M. is doing splendidly off of Tranquility, the epitome of the reliable storage locker. Many mock-ups are being tested and have been approved for further use in orbit and on the Moon; likely a major part of a future Artemis phase or for-profit related undertaking.

20. yes. yes.
    Then resurrection of Bigelow (whose plant can be bought for a bargain) and the re-imagining & reintroduction of the ill-fated TransHab project can continue…

21. not big and not 'all in one go'. Expandable/ retractable systems are very much less reliable in surviving launches, stable at erection, and fixable when partially- or un-erected. Less efficient structural capacity at mobilization.

    Better a standardized 'kit of parts' – regular, simple, interchangeable/ multi-purpose – likely erected and assembled by local, autonomous multi-tool satellites. Structure on the outside, occupiable/ service spaces on the inside of the volume.
    Also, projects that are incremental and upgradeable and scalable and phased. Ideally demountable and interchangeable. Less needed per launch before some kind of minimal functionality is possible. Hopefully, GEO or other upper orbit.

22. Ah "…fleets and swarms…". the joy of dealing with space debris. The elephant in the room for future mission risk mitigation. International guidelines, not ratified per se, and certainly not actively followed, include:
    – Design rockets and spacecraft to minimise the amount of ‘shedding’ – material becoming detached during launch and operation, due to the harsh conditions of space.
    – Prevent explosions by releasing stored energy, ‘passivating’ spacecraft once at the end of their lives.
    – Move defunct missions out the way of working satellites – either by de-orbiting them or moving them to a ‘graveyard orbit’.
    – Prevent in-space crashes through careful choice of orbits and by performing ‘collision avoidance manoeuvres’.

23. and so it begins…
    the cislunar real estate rush: the marking of territory where property and legal rights are ill-defined, barely respected, and poorly planned.
    Does one go big and dominating in crowded orbits – creating orbiting monstrosities under one flag or program?
    Do fleets and swarms of science, commercial, and military microsats/ mini-stations spread throughout as much volume as possible with numerous sensor, communication, and maneuvering options?
    My bet is on the upgradable and versatile skeletal gravity rings…
    https://orbitalassembly.com/projects?cslug=gravity-ring

24. Most of these projects, while cool concepts, still keep the conceit for launch mass that has plagued all space projects since day 0.

    A lot of the complications of space projects come from having to design extremely optimized, foldable payloads, with exotic materials and construction methods in one or two of a kind quantities, instead of launching a bunch of mass produced items with good enough quality and characteristics.

    It's normal we are in that situation, given space launches still are extremely expensive. To change that, we really need cheaper, bigger launchers.

    Hard no to sound like a Muskrat fanboy here, but Musk got the right idea to solve that: build a big reusable rocket that makes such conceits moot. Soon someone will start launching by the thousands of tons of good enough cheaper items.

25. We should definitely practice 3D printing large cylinders in space.

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