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Optical fibre made in orbit should be better than the terrestrial sort (economist.com)
107 points by godelmachine on Sept 10, 2018 | hide | past | favorite | 111 comments



> To say that this is truly an economic process is cheating slightly, since the ledger fails to account for the trivial matter of the $100bn or so spent to build the space station in the first place.

The ISS is a laboratory, I don't think it's fair to consider its cost as a factor here in the same way you don't consider the cost of the University campus for other research.

I highly doubt they'll be doing full-scale manufacturing on the ISS. They'll be using it (as it was designed) to conduct experiments on their technology and prove that it can be done. Only then will the real investment will begin where they construct dedicated manufacturing facilities.

I wonder if this would be an opportunity for Bigelow Aerospace's inflatable modules?


Why not just send the weawer fitted to a dragon for a few dozen orbits and then land the produce? With block 5 they can make the trip for 50 million. Unless the machines are too big it won't get any cheaper. Little logistics needed.


Wouldn't you then need to ship up all of the machinery every time, as opposed to shipping it up once and only shipping raw materials thereafter?


Yes, but you'd simplify logistics. Maintaining a space station is magnitudes more expensive. Construction, complexity, upkeep, loading logistics. If the machines fit, you almost always come out ahead cost-wise.


Why? Stabilisation, maneuvering, possibly shielding come to mind. Are those that significant? Do you have a source/ good explanation for this?


With a capsule you load the machine and feedstock comfortably on the ground, shoot it up and press the start button. Wait for it to complete, deorbit, unload. With Dragon you have about 6 tons of weight to work with, so even if the aperture is 1-2 tons, you still can process 4-5 tons of material. Fairly reasonable and achievable with the right design.

With an orbital station: first you need to build a station and keep it where it is (there are not a ton of orbital stations for a reason, they are expensive). If it has humans on it, everything becomes massively expensive. If not, well, you need future tech for onboard logistics and maintenance.

Even if you ignore the ridiculous cost of building and maintaining an orbital station, life support and other crew issues..

You still need to rendezvous, dock, transfer feedstock, produce, transfer product back to capsule, land. Even just a station that works like a printer with the feedstock seamlessly plugging in it would make everything more complicated and expensive.

Not even talking about how to fix your automated orbital platform when it breaks down.

Now in a few hundred years when we have massive orbital platforms with readily available workforce for hire and workshops for rent.. maybe then. But with today's technology you are looking at cost differences between maybe a 100 million all in with a single shot automated capsule (+ your stuff) vs. several billions for the most simple station designs + a ton of risk and technical hurdles.

Space is hard as we are fairly new to it (relatively speaking). It's all custom built as of now. Each moving peace you add increases cost exponentially. Adding humans just puts you on an entirely different chart altogether.


>I wonder if this would be an opportunity for Bigelow Aerospace's inflatable modules?

Not just Bigelow but many other space startups. SpaceX is dominating the news atm with Blue Origin to follow but the reality is that the big bucks are in space activities not space transportation. This is only now starting to be realized with companies deploying fleets of cubesats for Earth observation but in the next decade there are plenty of companies that are looking to build commercial space stations. Some of these projects are more conservative, like using technology proven on the ISS coupled with cheaper components and more streamlined operations. These 2 factors combined with the fact that these are not cost plus contracts with the government mean at least an order of magnitude of cost savings. Then there is Bigelow who wants to move to the next stage of inflatables but also the Gateway foundation who want to launch the materials in space and assemble a huge station there. Everybody is waiting for the price per kg to drop to a certain threshold and then cheap human transportation to be made available. Crew Dragon is probably the first step towards that that might enable some small station but the big deal is BFR( when and if it launches).


> the big bucks are in space activities not space transportation

This is an opinion, not a fact. They are presently in transportation. Moreover, the space mining and manufacturing pitch has been made (incorrectly) for at least forty years. I have yet to see a convincing business model for any of these activities, even assuming cheaper launch costs.


Actually launch industry is minuscule compared to satellites ($5.5B for launch industry vs $13B only for satellite manufacturing)

Edit: and then of course there is the satellites services which the report estimates in hundreds of billions $.

[1] https://www.sia.org/wp-content/uploads/2017/07/SIA-SSIR-2017...


42% is minuscule? They have reasonably comparable market caps considering the amount of time the industries have existed. The commercial launch industry really is in it's first/second decade (arguable depending on what you define as commercial, this field is radically changing), and you can trace satellite commercial use back decades to the 70's with GPS and telecom (the first satellite tv use was in 1978 for reference).


Of course satellite manufacturing is only a small part of the satellite industry. I updated comment to reflect that.


Even by their original figures, wouldn't it be 30%? 5.5B/(5.5B + 13B)?


The point is, to some people "miniscule" implies different orders of magnitude.


I'm talking about LEO activities right now. Satellite operators per year make way more than the satellite launch market is.


Lowering launch costs will dramatically reduce the value of stuff in orbit. It’s the brutal math that hammered the telecom sector through the 90’s and presents a major risk for the next few decades.

Ex: If you pay 1000$/lb to get something into orbit and your competitor waits 5 years to get better stuff into orbit at 500$/lb that means you need to lower prices while still paying back the same loans.


It doesn't work that way. If you paid 1k$/lb now and the competitor waited 5 years you got 5 years of profits which easily accound for 4 or 5 rocket launches on today's costs. Satellite operators make millions/day of operations.


What I think will be a very interesting development is when we scale a DaVinci Surgical robot from Intuitive to be remote-hands in the assembly of space things.

If we can have people simply logging into a davinci-style-space-avatar who can get about to do the tasks required to assemble things, and have the dexterity of these robots have, that will be an interesting step.

Another thing that shold be interesting is whomever develops the first orbital hangar.

If we were to start by sending up components which get lego-ed into a platform onto which we can attach things we are building, and the robots we build them with - then we will be able to develop a repeatable method of bolting things together in space.

Given that (from my ignorant perspective) the only real limiting factor to any space-born craft is the size and shape of the componentry which can be launched from earth to orbit - it would seem that just ensuring your minimal denominating factor is fitting into the weight/dimensions of the payload capabilities of the launcher.

Then, ensuring that things have a standard way to fit together would be great, but if not - use a davinci style romote-arms for the fine work...

Or is that all just naive daydreaming?


> What I think will be a very interesting development is when we scale a DaVinci Surgical robot from Intuitive to be remote-hands in the assembly of space things.

Most of that kind of surgery is done in the same room, so dealing with latency will be a major issue. (I know there have been some experiments in long-distance tele-surgery, but it's hardly routine.)

A low-earth-orbit installation (like the ISS) has a variable latency depending on where it happens to be and what chain of relays and other systems are being used. A geosynchronous satellite would have predictable latency (~250ms round-trip) but it'd be more expensive to launch and service at that distance.

Anywho, I think "remote satellite work" will involve heavy reliance on pre-programmed sequences, "simulate locally, then send for execution remotely" tactics, and just generally structuring the manufacturing process to minimize any steps that can't be done atomically with pausing-points in-between.


Yeah, I was more referring to the dexterity of the bots than anything else.


And frankly, it must be stopped. We can’t have loads and loads of space junk floating around in near earth orbit.

Space isn’t the internet, you “can’t move fast and break things,” and you can’t just create more of it. We have to be careful and systematic and decide exactly what is important enough to be placed into orbit.

Having a high cost at least prevents a glut of crap being put up there, if it doesn’t necessarily prevent meritless things from being launched.

Someone has to say humbug to this before the Lords of Silicon Valley screw it up and make the rest of us pay for it.


Poorly placed comment when the parent was discussing things like cubesats. Tiny satellites like these are probably better in the long-run for orbital debris due to a number of reasons. Firstly, by virtue of being smaller, atmospheric drag is greater and their decay is faster given a certain orbit. Second, they're more disposable than the larger sats, meaning lower orbit more economical when weighed against the capital cost of the mass-produced device itself.

The real problem for debris is higher orbits that don't decay after a reasonable service life. Those just accumulate forever.

On that subject, you would have a point for things like SpaceX's recent idea of putting up internet satellites, because those would be slated for orbits higher than more LEO missions, and would involve a large number of heavy objects there effectively on a permanent basis.


Atmospheric drag affects small satellites more than large satellites, all other things equal?


Roughly speaking, mass (which needs to be decelerated by the drag) is proportional to the cube of the size but drag force is proportional to square of the size; so yes, atmospheric drag affects small satellites more.


I think it's more than as you go smaller the mass reduces faster than the drag, thus resulting in a higher amount of drag per unit of mass.


In other words, typical cubesats have a low ballistic coefficient.

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


I don’t see how. You miss with cubesats it still ends up being a complete fucking disaster.

The point is that this all has to be done correctly and carefully. I see a very cavalier attitude about it because of SV startup culture and the expectation that getting things wrong is okay in the name of progress.

I’ll admit I was more directly thinking about stupid publicity stunts like Tesla Roadsters in space, but the gravity of the situation doesn’t really change because a mistake is slightly less of a disaster than an apocalyptic one.


The roadster is not orbiting the Earth. You lack understanding of the topic and thus fall victim to fear mongering by clickbait articles. Right now, with little done to protect from debris the chances of Kessler syndrome actually happening are tiny. Also most of the new constellations that are coming up in the following years will be in LEO where atmospheric drag is enough to get them down and burn in the atmosphere on their own within months of them malfunctioning. The problem is in higher orbits in which the amount of space is multiple orders of magnitude bigger and the number of satellites is much smaller as well. Also those higher orbits have little financial incentive for the new space age companies.


If I am not mistaken the roadster is not orbiting the earth it is in solar orbit near or past Mars. It's not endangering earth's access to space in anyway.


Cubesats are typically in pretty low orbits that decay fairly fast. I wouldn't worry about junk at that altitude very much.


Depends on the orbit: the ISS is in an automatically decaying orbit, as are quite a lot of near-earth satellites. It's geostationary that we need to worry about crowding.


We need to worry more about LEO. Orbits decay automatically, but less and less the higher you go while still within LEO. There are many polar launches which makes debris come potentially from any direction, while in GEO all satellites go in roughly the same direction.


Very little actual research has been done on the ISS. The occupants spend most of their working time on maintenance and housekeeping. So I don't think it's reasonable to label it as a research facility.

The ISS was primarily built to prop up the US aerospace industry, maintain human spaceflight capability, and give Russian rocket scientists something productive to do so that they wouldn't sell their skills to hostile countries. (And those aren't necessarily bad reasons to build a space station.)


The ISS is primarily an engineering experiment, not a scientific experiment. This is lost on most of its critics. The objective was to build and operate a large space station for a prolonged period of time in order to study prolonged human space flight, closed circuit life support, in-space assembly and maintenance, etc., in order to practice for longer and further missions.

There's only so much you can do on the ground. At some point you have to "ship it" (pun intended?) and get real contact with the problem domain. That's when you find out about the unknown unknowns. (This is true for any engineering effort of any kind.)

This was done after the Apollo era because while we did make it to the moon the technology stack was far too immature for a robust space industry. It was horribly expensive, dangerous, and not suited for longer term missions. I've heard many Apollo engineers and astronauts remark that it's amazing we didn't lose anyone on those missions. We needed to develop and harden our space flight experience.

During the same period we also worked hard on reusable launch vehicles. The Shuttle was the first serious attempt and was lacking in many ways, but it demonstrated that you could use an orbiter repeatedly. The Falcon/Dragon stack is more practical and represents a re-framing of the problem. It builds on Shuttle experience and also on the Delta Clipper project:

https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X

I'm not sure how much direct engineering transfer occurred, but some indirect transfer certainly occurred as I'm sure people in SpaceX studied this and other related projects extensively before beginning their own work.

We now have the technology to send prolonged missions with better safety margins and very nearly have a reusable (and thus more economical) launch stack to launch them.


In addition to this, it's important to note a class of scientific experiments that cannot be done by satellites that the ISS has been at the forefront of: researching the prolonged effects of micro-gravity and space-flight on the human body. This will be very relevant if we intend to send people to Mars or back to the Moon.


> At some point you have to "ship it" (pun intended?)

It's not a pun when you described the actual process behind the method of moving the cargo.


It's a thingism


Also, the article calls that a sunk cost, but the ISS is extraordinarily expensive to maintain on an annual basis as well.


The $1 million per km figure is of course complete rubbish. That's just the cost scientists have had to pay to fabricate it using the zero-g plane. There is no commercial application where the demand is that high.

The best commercial application for this type of fibre is a transatlantic crossing. In these applications typically 4 to 8 fibres are used and the distance is 7000km so the total length of fibre is around 50000km. For this sort of application the fibre cost needs to come in at around the $100 million dollar mark which is just $2k per km. To create a single km of cable in ZBLAN you need about 300g of feed-stock. So the revenue per kg is around $6k. This is below the current cost of around $10k per kg cost of sending payloads to orbit.


The cost of the raw ultra low loss single mode fiber (9/125 on a spool) for a transatlantic crossing is negligible, it's the cost of the cable when it's fully integrated as a cable with jacket, copper for repeater power, etc. And then the bulk of the cost is actually the massive engineering project that involves repeaters, possibly branching units, cable ships, ROVs, plows, divers, beach work, cable landing stations. I would guess that the fiber strands are way less than 2% of the total capex spent.


According to the originating NASA/UAH paper[1], where they took a fiber-making machine into their microgravity-simulating plane, gravity causes tiny amounts of convection inside the molten fiber. That's why you can't just float the fiber on air or something. Their guess is that the convection creates tiny little circular currents in the glass that are really excellent at causing crystal nucleation.

The core problem is that ZBLAN glass needs to be cooled down very quickly to solidify in the amorphous state. Drawing a fiber demands that you do it quite slowly to get a quality, consistent fiber. Drawing is not a technology that is going to improve hugely any time soon- it's too fundamental. Instead you need the microgravity to give you a little extra time to draw the fiber to the required quality.

[1]: https://www.researchgate.net/publication/8087775_Effects_of_...


Why don’t they just draw the fiber straight down? Problem solved!


The glass is still going to be under the act of gravity and will form convection loops but in a different direction to the loops if drawn horizontally.


That's how it's done normally


I'm glad to see this evolution become true. It's such a trope in SF literature that it's been the plot trigger of the latest Andy Weir novel, Artemis.


Which is a great book, by the way, that I highly recommend anyone who likes science, space and, a good heist, to read.


Seconded. The main character came off a lot like Mark Watney from The Martian, but what a great, quick read Artemis was.


Also an Excellent listen, the voice acting is superb.


I reached my "article limit" for the month, but it makes me wonder, HOW MUCH better could optical fiber be if made in zero-gravity?

Presumably it's all about material purity and accurate/consistent geometry of the fiber itself and the doping profile for refractive index cross-section.

If it were "perfect" how much better would the fiber be? Double the reach? So you cut in half the cost of repeaters/re-generators on long-haul links. Those are definitely expensive, but I think space flight is quite "up there" in cost too.


Use incognito to see it. The problem is that the glass needs to be cooled very quickly or it forms crystals, but drawing must be done slowly since molten glass can only flow so fast.

Microgravity has been shown to greatly improve the quality of the glass. The theory goes that convection (where hotter liquid rises past cooler liquid due to its lower density) causes small circular movements of glass that are really good at nucleating crystals.

> Those are definitely expensive, but I think space flight is quite "up there" in cost too.

The machinery is the expensive part. A million dollars of fiber, if it's 1 km, only weighs ~1 kg. On a Falcon 9 that's <$2000. Shipping and handling is usually a hell of a lot more than .2% of a product's cost!


> it makes me wonder, HOW MUCH better could optical fiber be if made in zero-gravity?

1-2 orders of magnitude less attenuation


>1-2 orders of magnitude less attenuation

Currently most of the cost of operating and deploying transatlantic fibre cables are the repeaters to boost the signal in between. If it is 1-2 orders of magnitude less attenuation, does that mean we could do away with the repeater?


I'd imagine yes, on some cables. If we can get 2 orders of magnitude, we go from needing repeaters every 90-120km to 9,000 to 12,000km.


They claim the kind of fiber (ZBLAN) fetches $1M/kg when manufactured on Earth. Looking elsewhere, I see that premium space made ZBLAN because it would be of higher quality could fetch as high as $21M/kg.

https://sites.google.com/site/cmapproject/case-studies/exoti...

Doing some back of the envelope calculations, a SpaceX cargo Dragon can return 3,000 kg to Earth. If they can achieve $1M kg advantage in value that would be $3B. Wow, that's enough to get anyone's attention.


> They claim the kind of fiber (ZBLAN) fetches $1M/kg when manufactured on Earth.

Because supply is so low perhaps?

> If they can achieve $1M kg advantage in value that would be $3B. Wow, that's enough to get anyone's attention.

I suspect the value would drop significantly as supply increases. Gold would be $1M/kg too if it were extremely rare and difficult to extract from the earth. As soon as it's less rare it's a lot less valuable.


I would guess the price is high because its really hard to make. And I doubt the cost of space made ZBLAN would be less than the cost of terrestrially made. The question is would there be enough demand for super high quality ZBLAN to cover the costs of doing it in space? If the value created by space made product was high enough it could kill off terrestrial production.

But I couldn't find any information about the size of the ZBLAN market, for all I know 3,000 kg could be many years worth of consumption. So, this is all guesswork but my back of the envelope calculation at least shows that the economics are not crazy.


> zero-gravity

There's a common misconception that LEO has zero gravity. You're barely off the ground so to speak and gravity is almost the same as on the surface. The difference is that you're constantly falling so you experience weightlessness.

So you are experiencing zero-g, not 0 gravity. You'd be hard pressed to go anywhere with an absence of gravity acting in that spot.

This being said the question is if the quality increase justifies the price (even for a hypothetical future mass implementation). Plenty of products get incremental upgrades, it doesn't have to be a massive jump. Again, if you can justify the cost.


> So you are experiencing zero-g, not 0 gravity.

You’re doing it, too. “g” is the acceleration due to gravity. Heck, scientists call drop tower experiments “microgravity” — it’s much less of a mouthful than “really quite a good approximation of free fall”. [0]

And if you believe in general relativity, LEO is a perfectly valid reference frame with no acceleration due to gravity (ignoring drag) but plenty of second order effects thrown in.

[0] I spent a summer at NASA’s Glenn Research Center doing microgravity combustion experiments studying how combustion is affected by the absence of gravity. I say that entirety unapologetically.


I was under the impression that zero-g is the accepted terminology for when you experience free fall (in orbit, in an elevator). Is that wrong?

Regardless of terminology, I tried to highlight the fact that floating in space is not due to the absence of gravity as many people assume. You're experiencing about 90% of the gravity at the planet's surface just that everything else around you is accelerating along with you.


As far as I know, people do call it zero-g. My point is that gravity is always around, so the more interesting thing to talk about is the acceleration due to gravity in one’s reference frame. For example, here on Earth, we usually neglect the Sun’s gravity unless we’re making accurate predictions of tides.


Yup. Creating a pedantic definition of zero-g to mean "no gravitational field" is pretty useless since you'll always be in the presence of a gravitational field no matter where you are in the universe. The accepted definition is just that your g-meter reads zero.

The term microgravity get used because things in orbit due to tidal forces, different orbital planes, air resistance, solar wind, and radiation pressure.

There's a lot of really strong feelings on the subject though. I'd like to think that GR would let people reach some common ground, but not so much.

https://en.wikipedia.org/wiki/Talk:Micro-g_environment


Hey, it's HN, it's the perfect place to clear up misconceptions. It's definitely not pedantry.


I would consider "misconceptions" which are irrelevant to the point being made to be the exact definition of pedantry. It detracts from the point being discussed, often is centered around some or other strict definition of a word, and is all-in-all about as constructive as being a grammar nazi. Yes, there is a gravitational field in LEO, but LEO is so negligibly close to an actual inertial frame of reference that for all intents and purposes we could (and do) call it one. The people and materials in LEO are in fact experiencing "zero gravity".

Calling it zero gravity is only technically wrong in Newtonian physics, but Newtonian physics are more than just technically wrong when it comes to the reality of general relativity.


Weird, your own explanation didn't stop you from discussing something that is not even tangentially relevant to the point.

My comment was meant to help and if it helped one person that's good enough for me. If you think calling me a grammar nazi (against your stated principles, might I add) helped anyone then by all means, trawl the web for opportunities to do it some more.


> You'd be hard pressed to go anywhere with an absence of gravity acting in that spot.

Okay I think I've found somewhere, but I'm not sure. What experiment should I perform to test that gravity is really absent?


Given the size of the universe and the fact that it's not entirely observable makes it... impractical to even consider measuring gravity. Where we can measure it it's done with accelerometers or doppler shift and measuring the orbital perturbation [0]. Objects close to home are studied more intensely.

You can't really conclude there is no gravity acting in some random point across the universe but you can use other methods to determine when it is acting even if you have no chance of putting an instrument there. Like gravitational lensing. [1]

There's definitely not enough space in a comment to discuss general relativity and measuring gravity of an object in free fall. But if you're curious for more and have time to read Wikipedia has one of the most accessible explanations that don't involve a pile of imperfect or misleading analogies. [2]

[0] https://www.youtube.com/watch?v=cMdjAKn_uXw

[1] https://en.wikipedia.org/wiki/Gravitational_lens

[2] https://en.wikipedia.org/wiki/General_relativity


You can't. You can only measure acceleration (with an accelerometer). If you get zero acceleration, you're in an inertial frame of reference and for all intents and purposes in zero gravity. Newtonian physics says you're technically wrong, but general relativity says Newton is wrong so you're okay.


It is better for making lasers, potentialy for laser weapons. Thats the new market that might make it profitable: small runs of expensive product where 1% improvements are monumental.


From the perspective of an ISP that buys a lot of many different types of singlemode fiber optic cable: This is cool and all, but we care about dollars per meter for cable purchase orders.

Until the cost per kilogram of launching stuff into orbit is drastically reduced (think: massive fleets of 100% reusable BFR-sized rockets sending stuff into LEO on a regularly scheduled basis), I don't see how this will have a real world application outside of special non-profit, government funded R&D projects.


This is quite interesting, the plot of Artemis by Andy Weir which is basically about a company trying to make fibre-glass in space might actually seem plausible.


Andy Weir and Daniel Suarez have a habit of using things in their books that you see on the news as new technology two weeks or months later. It's a little scary sometimes to see one of Suarez' thrillers show up in real life, and it takes me a bit to adjust to it being real without the dystopia.


Careful there, spoilers.


I remember reading "The Third Industrial Revolution" [0] in my childhood, which was a paean to all the different industrial processes that would be possible in space. One that I remember was alloys of metals with vastly different weights (lithium and lead, for example). In gravity it's hard to mix them perfectly because the heavier metal sinks, but that is not an issue in space.

Would be fun to read it again and see what predictions, if any, came true.

0: https://www.amazon.com/third-industrial-revolution-Harry-Sti...


Given that there is no industry in space I'd guess none.


I dimly remember that that book presumed launches would get much cheaper and more frequent. To be fair, before the shuttle flew there'd been inflated promises, and aerospace had progressed really fast in the preceding decades. It was a little like someone in 2000 thinking Dennard scaling wasn't about to hit the wall -- it's easy to think that was dumb in hindsight.


Well, there have been industrial experiments, which may have helped industry down here.


I think I'm missing a key piece in this article: it does not seem to explain why current fiber would be bad enough to need this, given its already incredible carrying capacity, even with loss due to imperfections and unintentional impurities. Without this, this just reads as "some people want to burn money for no good reason, yet again demonstrating that vanity non-problems are what gets you the headlines". Maybe it is, maybe it's not, but the article doesn't seem to clarify.


The current fiber requires multiple amplifiers across the ocean. The space fiber may allow to get away from it making it much easier to lay and maintain transocean cables.


Why would amplifiers make it harder to lay cable? You generally don't want one giant uninterrupted piece of cable over huge distances, even if it's a perfect cable, exactly because that makes it easier to do maintenance.


If the cooling can be done sufficiently quickly, it would be cheaper to make this stuff using a technique that Corning (maker of about 13% of all glass fiberoptics) has used for quite some time: producing it at the top of a tower and letting it drop and cool in free fall.


Got a link?


That reminds me of ZAFO (Zero Attenuation Optical Fiber), a plot-devices in the book Artemis by Andy Weir.


Manufacturing in space could have a lot of applications... but it's such a pain to get stuff into orbit and back.


SpaceX intends to get costs down to about $10/kg to LEO using BFR, almost as cheap as long haul air cargo. That is 2-3 orders of magnitude improvement and changes a lot of calculations.


The next calculation is how LEO transfers affects the environment/climate over the long term, when you begin using it as much as long haul air cargo...


Not likely.


In this case, they say a km of fiber is worth $1 million+. A 125 micron fiber weighs about 32.4 grams per kilometer, which costs $55 on a Falcon 9. So 20,000x less than the sale price.


That's why you capture an asteroid or mine the Moon.


I'm imagining a giant spool of optic fibre made from lunar regolith being wound back to earth directly from the moon


I was imaging a module on ISS feeding cable out direct to the surface of the Earth (impossible as ISS isn't geostationary). ISS is 400km high apparently, https://en.m.wikipedia.org/wiki/Fiber-Optic_Link_Around_the_... is 28,000km for comparison.

Perhaps with your plan we could put a giant spool at one of the poles and auto-wind it!


I suspect one day, in a distant future, we will discuss the issues of manufacturing with external forces ie gravity, and how only the best products can be made in environments we 100% control.


SPOILER ALERT: Sounds like the plot of the sci-fi book Artemis by Andy Weir. Great Book and there's also a kick ass Audible version read by Rosario Dawson


Any idea how gravity is the limiting factor in producing this?

The article mentions stress. But why?


Is it known if ZBLAN can survive re-entry stresses?


Inside a capsule? Sure, no problem. The issue with gravity is only during the very brief period when it is cooling from molten to glass phase.


Finally, that particular sci-fi trope is becoming real.


> It is a glass, made from a mixture of the fluorides of zirconium, barium, lanthanum, aluminium and sodium, that is therefore known as ZBLAN (sodium has the chemical symbol Na).

Acronyms!!! I know it is weird to bring this up but there is no NA in ZBLAN! It is AN and doesn't represent Sodium.

Would be neat if we could find a bunch of cases like this and give reason why we can expand into space manufacturing and a moon base. I doubt we will see this in our life times. I just can't see the financial benefit unless it is 100% automated.


From wikipedia: "...including a family of glasses ZBLAN with a composition ZrF4-BaF2-LaF3-AlF3-NaF."

Which seems to make sense.


That 100% does make seance BUT the author said Na is for Sodium which was made it not make sense to me.


Na is the chemical symbol for sodium because natrium is the Latin name.


They said "sodium has the chemical symbol Na" which is completely true, if intuitive.


Na is the chemical symbol for sodium. What's strange in the statement?


They probably confused 'sodium' with 'salt' and missed the Natrium in NaCl.

Apologies for linking to Quora:

https://www.quora.com/Who-renamed-Natrium-and-Kalium-to-Sodi...

If you want to explain an acronym that has its basis in the names of chemical elements you should probably use the same words the scientists that came up with the acronym used.


N is the first letter of Natrium, the Latin name of sodium from where the chemical symbol comes from. So I would say that the acronym makes perfect sense.


They seem to be using Na as a justification for using N, since the other chemical symbols don't match the acronym either. Unless they're just using the first letter of each symbol, either way it's not a great name.


If you use the Latin name for sodium, it flows much more clearly:

ZBLAN: Zirconium, Barium, Lanthanum, Aluminium, Natrium.

My grandmother, who was a pharmacist, prefers to call it natrium rather than sodium. I don’t know if there are any industries or similar where it’s commonly called natrium.

The sentence would have read better if the aside had instead been rendered “(sodium is also known as natrium)” or similar.


Fun fact that I recently learned, the person who named aluminum was Humphry Davy and he originally suggested "alumium" but ended up choosing "aluminum".


It would be interesting to find out how that became "aluminium" in England. Perhaps they were more interested in retaining the "ium" suffix.



Some languages use natrium instead of sodium.


I did some statistics on the translations at https://en.wiktionary.org/wiki/sodium#Translations

Of 107 unique language-word pairs (some languages have multiple words for sodium) there are 53 starting with [nNнν], all of which are some variation of natrium (they are in 51 languages because Icelandic and Roman have two variants each). Likewise, there are 37 starting with [sṣ], all of which are some variation of sodium. The remaining 17 are either different or no transliteration is available to check.


Might want to review what an acronym is. :)




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