Nanotube Strength, Bad News for Space Elevators [2019] 

Space elevators are more realistic for smaller planetoids and moons where you dont need as much cable strength

Who would've thought that after all of those years of studying for school, I merely needed to adopt an armchair configuration to achieve the highest GPA... /s

"This is totally going to revolutionize our current process." Several years later, "Yeah..., thats not gonna work anymore because so and so."

Atleast they can replace copper windings in electric motors and make it more compact lite and powerful if not in the elevators yet.

4:17 I very strongly disagree on the time arguement. To launch a rocket it takes weeks to prepare and build. Rockets can also fail. An elevator is there. Put it in, push the button. Time is not relevant when you can save just a tiny bit of money. I will refer to the Concord Aircraft in this matter.

I love how HL3 was announced the day after this was uploaded

Wtf mate. Your channel is much more worth it. This editions, are AWESOME. I love them, and you explain all with clarity and order. It's profesional, keep it up mate. I cant figure out why youre having such a low number of visits.

36000km elevator : irrealistic continental bridges, heavy elevators in mines or skyscrapers : still possible

Zero-defect tubes will only be made with carbon direct-deposition, not chemical-to-carbon translation via burning. We're getting there.

I wonder if chiral nanotubes with regularized defects could create super elastics without the use of rubber. 🤔

"sits in his room in the 70's"...sits typing at a computer, what?

Seems to me like we're still at a very primitive level in terms of building nanotubes, trying to squeeze out order from highly random chemical bulk processes. Seems to me the only way we will ever get perfect nanotubes of any significant length will be by assembling them with nano machines which would act in some way similar to how ribosomes assemble proteins. We will of course first need to build the nano machines and that might even be done through the route of bio-engineering by modifying existing biological machinery rather than starting from scratch. With all that however there is still the problem of defects forming after manufacture so there will always have to be an allowance made for defects no matter how perfect it was originally. Such defects will inevitably be caused by ionizing radiation from the carbon 14 present as part of the nanotube material as well as more significantly external radiation, which in space is no trivial amount.

"IGNORING SCIENCE everything's possible"

Although the monolog was for the most part well understandable, I would like to suggest that the speaker pay attention to the pronunciation of the word "attributed". When I played the model pronunciations from dict.cc, all but the one from an Indian lady were as I would expect and consistent with the pronunciations given in print dictionaries of British and American English. The bit difficulty is how the word is used, as verb or noun. The verb has the emphasis on the second syllable, whereas the noun is emphasized on the first syllable.

2:48 I'm very very annoyed seeing earth spinning backwards......

Eh, I'll stick to my orbital rings and atlas towers.

This parameter tuning smells like a job for an evolutionary algorithm or other machine learning technique.

You make amazing high quality and very informative videos. You should be up there with the large educational channels

We still ship almost everything via cargo ship, freight train, and semi truck despite having the option to fly. If we built a few space elevators, people would still fly in rockets but nearly all cargo would go by elevator.

So imperfect carbon nanotube Can’t make space elevators Guess we need to wait for nanobots/nanomachine Or composite carbon nanotube of some kind

In lesser gravity wells like the Moon or Titan these cables could really work and not be unfeasibly long.

I think another important strength aspect would be how you weave the tubes together to make fibres. Or stack them to make solids?

Correct balance of humor, art, science, and wishful thinking. Your time and effort is much appreciated. Please continue to keep it casual like this. Feels like having a long discussion with an old friend over tasty drinks and snacks.

2:40 : One of my pet peeves is depictions of the Earth rotating the wrong way. It wouldn’t be so bad if it weren’t happening in science videos.

Forget space elevator, embrace orbital rings. Thanks for the vid.

even if you got launch costs near zero, the infinite reusability with only electrical power makes it worth building one over using rocket fuel for everything.

4:10 spacex fuel cost for spaceship(+superheavy) launch 1m$, near future internal cost 3m$, probably later 2m$, for 150tons cargo.

While you're crushing dreams you should look into actively supported structures like launch loops :P

Keep in mind there will be an astronomically large 'wobbly bridge' effect. You need strength + rigidity or a means to anchor it down properly.

It’s not as much of a pipe dream as you might think. 35,000 km is long, but it’s not too far off from the length of all the fiber optic cables all across the planet. Moreover, carbon nanotubes aren’t “the one” thing that could make space elevators a reality. Graphene by itself could do the job, and so could diamond nanothreads, as well as boron nitrate nanotubes. Also, the travel time is a bit misleading. Yeah it would take days to climb the elevator, while it only takes a couple hours to launch a rocket, but rockets also have to wait for ideal weather conditions. Because of the massive tension on the cable, it will be extremely rigid to the point where even a hurricane couldn’t damage it. Furthermore, there’s a fundamental barrier for rocket launches that not even SpaceX can overcome. Launching larger payloads fundamentally costs more and more, and until we get fusion powered rockets, it will always be the more costly option next to an elevator ride. Finally, the most important thing to keep in mind is the promise of space elevators. Just by letting go of the cable at different lengths, you can literally launch anywhere in the solar system, no rocket fuel required.

Just triple braid the armchair structure and put a tension gyro on the satellite and on the ground to eliminate as many Pascal's of pressure possible and reducing quick snags from various elements like high wind. Cable dampeners all the way up the ribbon to reduce sway as well. Scaling to size a strength is always the answer.

There is an interesting new video about skyhooks in Kurzgesagt.

And then a single cosmic ray will ruin one carbon atom and collapse the elevator

Will a space elevator work on the moon?

Space elevator, even if they could make a tether long and strong enough; can still never be practical. The reason is that all failure modes are catastrophic. I will leave the dear reader to imagine what those are.

A single strand may only have a GPA of 200, but bound together in a woven rope those strengths are multiplied. Anyone can pull apart a single strand of nylon, but if you weave 100 of them together you will not pull it apart.

And if it works once - how long will that totally unprotected cable hold when a heavy payload runs up with 400mph ? Any protection would be a lot weight and each ride is a lot of mechanical stress.

@Subject Zero Science I recently found this channel and I am blown away!!! You have amazing production quality, exciting topics in science, and you are a great narrator. Thank you for your channel

If you have the space elevator terminate at 20 km, you will only need a cable of 6.3k gpa, not 65k. A hot air dirigible can deliver the elevator car to the cable, which then can take the elevator to space. Simple.

The classical space elevator might not be practical, at least not in earths case. However what might be worth looking into is orbital rings that utilize active support which could in theory be built inside the atmosphere. Brief rundown of the concept: You effectively have a ring that constists of 2 main parts, an outer hull which would be geostationary and an inner ring which is actually orbiting the earth. The inner ring supports the outer hull via magnetic levitation, however it needs to spin much faster than would be ordinarily necessary if the entier structure would be orbiting the planet. Imagine it kinda like a reverse Hadron Collider, instead of the outer parts supporting the particle stream it is the particle stream that supports the outer parts, i hope that analogy makes sense. So, given that this method can achieve geostationary status at much lower altitudes it should make space elevators that connect it with the ground much more practical, we're talking 1 hour trips to space at 600km/h. If we now also put trains on the ring you could be anywhere in the world within 4 hours since those trains could quite literally travel at orbital velocities and you don't have to connect the elevators exclusively at the equator, as long as the forces that the elevators put on the ring cancel each other out. The "only" drawback to this method is that it is an even more massive undertaking than a classical space elevator would already be.

A video from subject zero science AND singularity prosperity in one day? Dear god all I need now is some isaac Arthur and I'm pretty sure I'll have proof that this is all just a simulation designed specifically for me

This is why we need to build an orbital ring; all the perks of a space elevator with none of the drawbacks.

Active structures and orbital rings to support the elevator would get rid of the need for impossible strength cables and instead require impossible power production.

It is also not a "hard" requirement to go all the way to geostationary orbit distances. A MUCH closer satelite with station keeping could also suffice similar to the starlink satelites.

Space elevators are fine for the Moon and similar small things. But when talking Earth, what you REALLY want is an orbital ring. Steel cables are strong enough for that purpose. First step to that is making some structures with active structural support to get people used to the concept. Maybe a very tall lookout tower to bring people from all over the world to look out from several kilometers of height.

I can't wait until the next patch for this version of our simulated reality. Next update has some sweet upgrades. I think the space elevator is in the next patch. No word on fusion patch though.

Elon Musk recently told that Starship would cost SpaceX about $2,000,000 to launch. It has a 150T to LEO capacity, so about $13.33 per kilogram...

Nest the tubes with alternating grains. You get the insane strength numbers. Good fucking luck manufacturing that though.

Using graphene advancements within technologies will absolutely be able to be utilized in space elevators. All we are talking about is purity and uniformity of material, which is inevitable.

A really well animated video! Anyway, just had some thoughts to share. (I'm finishing up a thesis about artificial muscles and part of it has to do with carbon nanotubes) Carbon nanotube yarns have been producible since 2004 but aren't talked about very much which surprises me, it was the beginning of a pure CNT thread (so it keeps its mechanical strength as well as thermal/electrical conductivity, where other polymer/CNT composite threads could not). You can make the sheet of CNTs like you showed in the video, but also you can just pull from one side of this sheet, and while twisting it, you can make a yarn. just a square cm can make something like 2m of yarn or something like that. So now, the cross section of this small yarn that is maybe 3 microns has hundreds of thousands of carbon nanotubes. More tubes = more load, it would be interesting to see how plying together the yarn many times over would do to its strength. So instead of purely depending on intramolecular bonds of carbon, there are many tubes applying friction forces to each other as well (Zhang et al. 2004, 2011). Maybe if clever manufacturing is used, like some kind of continuous CVD production with yarn drawing, huge thick ropes of CNTs can be made and space elevators can be a real thing :)

Man you really need to check out ISEC work and research. The space elevator cable will be made of ribbons of single-crystal graphene, maybe with an outer layer of boron nitride.

I'm a bit late but i've read somewhere that space elevator would allow to transport radioactive materials safely into space (this allow building a nuclear propuled spaceship that could go interstellar)

That AKIRA poster won me over. Subbed for life. Yes i also enjoyed the video and it content. Keep them coming. Cheers. :D

I knew 1 and 3 arrangements existed for octagons but I never knew their name before. Thanks for teaching me something new. Also, you have a new subscriber because science is cool.

even if we can super mass produce the critical armchair configuration, we need R&D of bonding strategies, nobody has addressed this issue publicly nor offered any tentative solutions ~ personally, i'm a fan of the concept But we Must address these issues Before we attempt even a prototype

Orbital rings ftw!!

has anyone calculated the strength requirements of a "cable-web" shaped like an inverse Eiffel Tower,,, where out in space are multiple orbiting bases,,, which are connected by a web of cables that converge towards earth to a single elevator base??

Graphene can also be used. What about kevlar or UMWHDPE? Dyneema is very strong and has low density, unlike nanotubes it's easy already to manufacture and relatively cheap but has low melting point.

doesn't seem too bad there are a lot of common misconceptions both about space elevators and about material strength the thing is oyu could hypothetically make a cabe using a relatively weak material as long as you taper it making it thinner at the ends and thickest at geostationary orbit the problem is that htis would have to be exponential and with a normal material the diameter at geostationary orbit yo uget would be absolutely insane so it would no longer behave like a rope which would make things even worse but with nanotubes even if they aren't quite up to the ideal strength one might hope for it's feasible if you taper the wire correctly - the biggest problem seems to be how to actually turn these into a workable material, probably by working them into a compound

5:43 What is Carob fiber reinforced plastic... :D :D

Does the concept of a Space elevator even work? Wouldn't pulling up a load up the cable slow down the orbit of the counterweight by pulling on it? Therefore you still have to spend rocket fuel to accelerate the counterweight each time

An orbital ring would require ordinary materials only and its height (LEO) is a fraction of the geostationary height so the time to get there would be correspondingly less.

An orbital ring is a far more useful concept than an elevator and doesn't need such strength of materials. Similar scale in terms of 40,000km ring in orbit, but it only needs to be under low to moderate strain, not it's entire weight. And it can be in a 200km LEO and the elevator component would then only need to support it's own weight over 200km instead of 36,000km. It also would be a quicker trip up to orbital height, and useful for launching in to orbit using the ring as a track. Even kevlar is good enough for most applications, no need to hang everything on the production of nanotubes in bulk.

Apparently, 1-atom thick carbon chains (-C≡C-C≡C-, etc., or possibly =C=C=C=, etc.) have been grown inside carbon nanotubes. I wonder if that could be used to increase tensile strength. Obviously, these chains are even more sensitive to impurities than carbon nanotubes, but maybe it could still help with tethers made of lots of tubes with the defects at different points.

So we'll have to taper the cable a bit more... problem solved?

For those wondering, 130'000'000'000 pascal is 13'000'000 tons per meter or 1'300 tons per cm.

Great video! I loved the reference to Cave Johnson from Portal at the end haha

WOW! GREAT I formation. Thank you!

This video makes it seem like space elevators will have human hair width cables for some reason. A few comments have stated, "why don't we just weave the cables together, thus alleviating stress on the structural integrity" The answer is because that is EXACTLY what they plan to do! Will the cable be heavier if woven together to become stronger, YES it will, but no scientist or engineer is under the delusion that a human hair sized cable is supposed to somehow support the stresses of a space elevator AND carry loads containing equipment and people off world. Just because a carbon nano tube is stronger or less strong under EXTREMELY specific, near microscopic circumstances does not mean that spells the end for a space elevator. This video does contain relevant info if we are talking about carbon nano tubes and their individual structural stability. But it is not considerate of woven carbon nano tube cables and their designs for space elevators on a large enough scale to cause structural instability. The title is mere click bait.

Fabulous channel that I have just discovered... love the content. Subscribed! :D

Little to incentive at all? Energyefficiency? Do you speak it?

The space elevator incentive isn't about getting something somewhere faster, it can also be something to be used to help ships get into orbit faster without having to use a ton of fuel . Well this video is clearly full of superficial research so I don't think would be worth even going further, it really is just so shallow..

Most of the issues with a space launch is just exceeding the thickest part of the atmosphere so much much smaller towers are all that's needed. Something more like a marine spar, or buoy where the tower is either anchored or ballasted at one end and has buoyant support above it's centre of mass but the structure rises much higher much as an oil drilling rig works. Such a megastructure and it still would be a megastructure would be barely 1% that of a space elevator. Ultimately, a space elevator is a way of avoiding the need for propellents and having the power source be external to the launch craft and there are other ways to achieve some of this. Indeed there are many non-rocket space launch concepts that involve a fraction of the structure of a space elevator so a space elevator is the least likely of such concepts to be attempted on our planet. As to single wall nanotubes not having enough tensile strength, that's not to say that multi-wall nanotubes, filled nanotubes such as with cemetite, or active forces such as magnetism strengthening the nanotubes might suffice.

Let's not forget that there is also a 300kv charge differential between the ionosphere and ground. The atmosphere is a dielectric insulator that a space elevator would bypass. As it is, some of the charge potential travels along the field lines of the magnetosphere while others descend through the atmosphere charging up storms and then descending further as lightning discharge. Building a space elevator would bypass this protective circuit and connect that 300000 volts to ground. No one knows what this would do. There are a lot more issues with a space elevator than just the tensile strength of a cable.

I don't understand why everyone ignores the fact that you can also reduce weight using balloons of warm helium. Graphene is atom tight, so the helium will stay in there. So now you have lift, which obviously dramatically reduces the weight of the cable, reducing the required strength of the cable. What am I missing?

You referenced graphine a few times but I whish you eould have extrapolated on it. Graphing has a specific surface area thats about 2.6 times that of carbon nanotubes, and has a theorized tensile strength of up to 130GPa and a stiffness of up to 1TPa. Its also said to be self repairing if carbon molecules are introduced to the damaged area.

no scientist here, but if it can conduct current it can produce an electromagnetic field. a strong magnetic field can increase the strength of the cables by increasing the surface area of the overlapping cones that make up carbon nano tubes. and give them strength by de-creasing bond length. a strong magnetic field needs to given thought.

So in the video it is established that carbon nanotubes do have the strength necessary to build a space elevator with them, but that the technology of today is not capable of producing the quality of nanotubes required, and concludes that therefore a space elevator is not possible. This is all equivalent to someone in 1910, just after the Wright Brothers flight, offering opinions on the state of aviation we can expect in 2010, them basing that opinion on the technology of 1910 and offering the conclusion that intercontinental flights are obviously impossible.

Not to mention lightning strikes on the cable, and possible energy transfer between the ionosphere and the ground that could fry the cable.

Forget about the space elevator, i.e., a cable from Earth's surface to geosynchronous orbit. An ORBITAL RING can be at any height, such as LEO, and therefore requires tensile strength within that of existing materials.

what about a space straw? use negative pressure from space to pull things inside the tunnel upwards then use gravity to get things down.

If I'm not mistaken, you're measuring the strength of a single strand of carbon nanotubes, no? I'd imagine that by threading many strands together into carbon nanotube ropes, we could increase the strength further. Given our issues with making perfect nanotubes right now, this would distribute the load across many strands evenly, reducing the reliance on anyone one strand being perfect at any one point.

The space elevator has always been sci fi nonsense, and not even the "hard" type of sci fi. It's crazy how many 'serious science' youtube channels covered it as if it was something that could ever work on earth, or that it was even a good solution to the problem. Even for the moon it's a terrible idea. Long story short, if you have the tech required to build a SE, you have the tech available to build a much better solution to the problem you are trying to address.

Just love the Arthur C Clark scenario shown with an Akira Poster from 1990, hanging on the wall... Though it's supposed story hails back to the feudal times of Japan and isn't high tech...

Wow, I also find it extremely strange that there's no literature on the role of graphene orientation on nanotube strength. After all, even at first glance those graphene sheets do look anisotropic as f**c. So weird. Perhaps until recently there was little control over the structure of individual NTs so there might not have been strong incentives to test their individual properties. Although I'm just making conjectures.

Again great quality videos. I am a long-time blender user and would love to know how you do all the text animation and FX? is that still blender?

Also what about new materials like that aluminum impregnated glass? Maybe making fiber glass rope from such a material would be stronger? Too bad you can’t swap compressive strength for tensile.

did you see the spool out of the test cable years ago? the voltage across it burned the test cable

alternative: lower estimation for strength of carbyne equals 251 GPa

Are we talking about single layer graphene structures or have they tested the tensile strength of multi-laminated tubes. Wouldn't more layers add additional strength in more directions? The space elevator would act more as a rail gun so you might not need as much cable as originally planned unless geosynchronous orbit is your objective but you could probably get a payload into orbit with less material.

Well I think even with Space X, Space Elevators still have a room even if it takes days to get to space. Much like we still have trucks, air plains, ships, etc. Different methods allow for a big cost difference when we talk about how much weight we are planing to send up. While air plains are faster, they also cost the most to ship anything anywhere while a ship will cost a fraction of that but might take an extra day or two. The other problem is we can only make a air plain so big and a rocket so big as well - so that is where Space Elevators will over take larger object as well thus even if Space X could get the cost down it would still have limits in what it can send up to space. There is another way to shape nanotubes as well that could increase all the propeterys going forward. Over all, I think we're on the way to making this happen. It'll just be another 100-200 years before we see it sadly.

I don't think an elevator would work... First problem being the force pulled on the spacecraft would likely cause it to be pulled down. They give a solution to this, which is to add a counter weight to the spacecraft on the opposite end (using centrifugal force to counteract the force of the object being raised). The problem now would be calculating the load against the spacecraft during an elevator operation to avoid orbit decay. (And there is that pesky thing where the weight will just enter orbit and not contribute as a counter weight). I say all of this knowing that it would be impossible because the spacecraft would have to travel at the same speed of earth rotation (geostationary orbit). This would require the craft to be about 22,000 miles from the earths equator. Compare that to the average orbit of around 100-1200 miles. Such a far distance would highlight a very big problem with any material... elasticity. A rope that long would have miles of stretching, and any deviation on the craft x axis would translate to miles on the ground. It's a neat thought, but completely impractical. A better idea would be to construct a 100 mile tall pyramid with elevators in the center. The fun part is figuring out how many Home Depot trips it will take to build, and how wide the base would have to be. In the end, regular liquid fuel rocket engines are by far the best option we have, or until a new fuel is implemented. (I'm looking at you metallic hydrogen)

Not to mention Conservation of Angular Momentum, where lifting a weight from the equator, traveling at 1600km/h up to geosynchronous orbit, traveling at 11,000 km/h would cause the lifted load to pull the cable backwards, reeling in the counterweight, until it all crashes to earth. In physics, NOTHING IS FREE.

Wait wait wait. You are arguing that shooting up rockets will actually be cheap enough, that a space elevator won't be necessary? Why would the high grade rocket fuel, with all the additional costs of operating these things, ever be as cheap? With an elevator you only need electric power, and you'll of course have solar panels above the atmosphere, in addition to whatever power source you have on the ground. It would be worth it to even build a complete dedicated nuclear power plant solely for the elevator. Because this thing can haul ton after ton constantly. Who cares about how long the trip takes? I say let it take a week or two to save power. We waited for thousands of years of recorded history, and now a few days more is supposed to make a difference? No, the elevator will be crucial for space mining and construction, which will be the things we need in order to expand. And we need to expand before Earth is met with some sort of catastrophic end. Colonizing outside this planet is the most important existential challenge to the human race. It won't be achieved by dabbling with rocket ships.

Man those S's are coming through really harsh, kinda rough on the ears

Tethers may still prove very useful in boosting orbits and perhaps in getting objects to orbit, even if the classic space elevator is not a realistic option.

Still sounds like its doable, just thicker, but, certainly this is morw than enough for a sky hook, which could be more useful

Damn, its a bummer that the keystone technology for space elevators is getting delayed that way, but it shouldnt discourage us to look for alternatives to "whats the most cost effective explosion I can launch behind me". I think space tech has suffered from its prohibitiv entry costs and therefore innovative ideas to solving our gravity well problems. Hopefully something like maybe metallic hydrogen, mass launchers, orbital rings, sling ports,... can be tried and tested instead of the same old same old.

All about the sky hooks mate

The space elevator cable would need to be a single macroscopic multi-walled "nanotube" and then it's fine.