Diamond Nanothreads Could Support Space Elevator (space.com) 171
Taco Cowboy writes with news that Penn State researchers have discovered a way to produce ultra-thin diamond nanothreads that could be ideal for a space elevator. According to the report at Space.com, The team, led by chemistry professor John Badding, applied alternating cycles of pressure to isolated, liquid-state benzene molecules and were amazed to find that rings of carbon atoms assembled into neat and orderly chains. While they were expecting the benzene molecules to react in a disorganized way, they instead created a neat thread 20,000 times smaller than a strand of human hair but perhaps the strongest material ever made. ... Just recently, a team from the Queensland University of Technology in Australia modeled the diamond nanothreads using large-scale molecular dynamics simulations and concluded that the material is far more versatile than previously thought and has great promise for aerospace properties.
Kim Stanley Robinson (Score:1)
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And The Foundations of Paradise, Arthur. C. Clarke.
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Clarke's science > Robinson's science.
For a large factor of >.
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There's 'a lot of very serious engineering concerns' when building bridges and skyscrapers, too. What's your point?
Nobody is looking for a 'magic material', any more than *steel* was a 'magic material' when it came to building bridges across the Mississippi. We already know the properties needed, and even have some viable candidates where we need to figure out how to mass produce long fibers.
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Yes, that's why we don't have steel, because it "isn't in the periodic table"; that's why we've discovered all manner of interesting properties in materials that aren't "in the periodic table" but are derived from combinations of the elements, various crystalline and other molecular arrangements of those structures, both those found in nature and those that have arrived courtesy of, you know, science.
The science takeaway -- as opposed to your "man can never fly" mode of reasoning -- is that this is a materi
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The obvious example is FTL travel/time travel.
Also, the "it's just an engineering problem" misses the point that you can't separate engineering from economics and politics. We know that we could all be flying in supersonic passenger planes now, because we built Concorde. But there are no supersonic passe
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I've done real work on solving the FTL problem - about 50/50 solvable. - Solvability ultimately depends on the ability to capture or create then contain negative mass matter. The biggest brake on the whole thing is that general relativity the dominant theory in the field for the last 100 years is complete nonsense above the speed of light. - You can have two of the three - general relativity, black holes, conservation of momentum..
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I don't see how general relativity could possibly give nonsensical answers to questions involving objects traveling over the speed of light, since (a) it isn't intended to work with FTL, and (b) nobody knows what FTL would be like if it were possible, so it's difficult to say that predictions would be nonsense.
You seem to assume that we can have matter of negative mass. The fact that we could do neat things with it doesn't mean it can possibly exist.
What does general relativity say about black holes a
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Hi. The real problem with both general and special relativity is that they both rely on the idea of time as dimension, which is generally incompatible with most FTL models. In my version time does not behave as a dimension at FTL speeds, instead time is point like giving a 3 Dimensional space time - so time travel is impossible. (In the FTL model 4D space time still exists at quantum scales, but becomes non-coherent at the quantum limit.)
There is certainly no hard proof for this version of the FTL but equal
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Let's see. First quote: that's from well after US tests bombing and sinking several obsolete warships, including ex-German battleship Ostfriesland, and at least a decade and a half after most admirals considered carriers of importance only second to battleships (and many not with the qualification), You picked an idiot saying something stupid, that most admirals of the time would disagree with.
Einstein's comment may have been dead on in 1932, for all I know. That changed fairly rapidly.
So, what you
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And The Foundations of Paradise, Arthur. C. Clarke.
I think you meant Fountains of Paradise [wikipedia.org]. Another sci-fi great, famous for his three laws of robotics, did write something called the Foundation [wikipedia.org] trilogy. A space fountain [wikipedia.org] appears to be different from a space elevator, but I'm no expert on the distinctions between these and other combustion-free space launch concepts like the skyhook or orbital ring.
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Annoyingly, in a post I typed previous to this one, I put Fountains... bloody fingers.
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Nah. No desire to revisit that Communist propaganda. Might as well have been published in The Worker.
Neat engineering concepts, but his sociological stuff in there was nauseating.
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You wouldn't know communism if you were planting potatoes in a collective.
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But (Score:2)
Will it last forever?
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...and how will we get it down? [youtube.com]
Re: But (Score:5, Informative)
From the perspective of a space elevator, it's not. Read this paper [arxiv.org] linked from the article. There's no talk of space elevators, that's just their way to entice the reader into listening to them.
That is to say, the space elevator mention is just clickbait.
As the paper notes, "experimentally measured tensile Young's modulus for SWNTs ranges from 320 GPa to 1.47 TPa with the breaking strengths ranging from 13 to 52 GPa". A material with the density of SWNTs is generally considered to need at least 100-120 GPa irreversible yield strength (less than breaking strength) to make a "practical" elevator (although if you read those proposals it's hard to come across with any conclusion other than that they're being way too optimistic even with those numbers). Note: 13-52 GPa for individual tubes. Ropes of multiple tubes are 1-2 orders of magnitude weaker.
So what about these diamond nanothreads?
Their data is pretty consistent, with graphs showing a clear dropoff and stabilization around 56 GPa. Obviously nm-sized fibers are pretty worthless for the purposes of an elevator, there'd be way too little Van der Walls holding them together into a rope.
Now, these are just simulations. But more often than not real world seems to underperform simulations rather than overperform, so I wouldn't get too optimistic about the real-world greatly exceeding these figures. For example, early simulations of SWNTs said they'd be around 120GPa; few believe nowadays that they can even approach those figures.
But what about the density side of the equation? After all, a material can be weaker, but if it's correspondingly lighter, then that's not a problem. The density is not in the paper, but this [researchgate.net] cites the tenacity (breaking strength over mass) as 4.1e10^7 N-m/kg. While the yield strength is going to be a bit less than the breaking strength, it shouldn't be too far off - this means that the density should be somewhere less than - but not too much less than - 1,37g/cm^3. That's on the same order as SWNTs, unfortunately.
Short answer? We're still nowhere even remotely close to being even capable of making a space elevator.
Space elevators face such numerous problems anyway (really don't want to have to go into them all) that they're really not a fruitful avenue of pursuit. We'd do far better to direct such efforts to more realistic access methods, such as a Lofstrom loop [wikipedia.org] or variant thereof, which requires no unobtanium and is far more efficient (space elevators lose huge amounts of energy to transmission losses, throwing away a large chunk of the advantage that they gain from bypassing the rocket equation). Active suspension via recirculating kinetic transfer, by one means or another, is something we can do today.
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That is to say, the space elevator mention is just clickbait.
This has been happening a lot lately. Just a few articles down is a mention of videos of "execution-style killings" that apparently either the submitter or an editor (ha!) added for clickbait.
/. community to discuss the article in question properly. We don't need some editor giving our discussions "direction", rather the whole point of /. is as an avenue for peopl
I'm not sure if the discussion that these things adds increases site revenue or not, but it completely destroys the ability of the knowledgeable
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Did you RTFA? I'm not normally one to defend /. editors with their crappy proofing and duplicates, but in this case the click bait comes from outside /.
The original article and a few others:
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Did you RTFA?
YMBNH!
But thanks for pointing that out! It tradition that we levy criticism but don't take the time to verify sources!
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Short answer? We're still nowhere even remotely close to being even capable of making a space elevator.
Space elevators face such numerous problems anyway (really don't want to have to go into them all) that they're really not a fruitful avenue of pursuit.
For the Earth, sure. What about for the Moon, where gravity is only 1/6g and there's no atmosphere?
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The moon's rotation is tidally locked to the earth (1 rotation/month makes it hard to stay in lunar orbit unless you are really far off & anything orbiting the moon that far off would be gravitationally perturbed by the earth) makes a classical beanstalk impossible. Other solutions like a rotating skyhook are theoretically possible but the mass concentrations make even that iffy.
Posted as anon to conserve mod points.
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Unfortunately, for a space elevator, much more important than gravity is the spin speed of the celestial body it's attached to.
It needs to reach beyond the geostationary orbit of that body - meaning orbit of period equal to rotation period of its base body. That way it remains stretched.
Moon, with one spin per month, has no geostationary orbit at all (it's located beyond its Hall Sphere, meaning the Moon's gravity there is too weak to create orbital motion). So - no lunar space elevator, not due to technolo
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I see, thanks for the detailed explanation.
How about Mars? Or what about a hyopthetical Moon-sized object with an Earth-like rotational period? Is there any situation where a space elevator actually makes sense?
Lofstrom Loop still seems dicey (Score:2)
I think that a space elevator is entirely impractical for a planet with an atmosphere (and air traffic); aside from the material science challenges, there is just too high a risk of one errant aircraft or piece of orbital junk taking the whole thing down.
The Lofstrom loop cited by the parent poster is interesting, but seems to suffer from some of the same material science and fragility issues. Its energy consumption when idle is also an enormous cost factor (the power required to overcome atmospheric drag w
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The other option instead of an aircraft could be a linear accelerator up the side of a mountain. 1G over a 10km track comes out to a 1600km/h endspeed. This would be about 1/3rd of the velocity required for a very low earth orbit, and spit the launch vehicle out above the thickest bit of the atmosphere. If the track is sealed at the bottom
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We'd do far better to direct such efforts to more realistic access methods, such as a Lofstrom loop [wikipedia.org] or variant thereof, which requires no unobtanium and is far more efficient (space elevators lose huge amounts of energy to transmission losses, throwing away a large chunk of the advantage that they gain from bypassing the rocket equation). Active suspension via recirculating kinetic transfer, by one means or another, is something we can do today.
Great post and I'm all for any crazy contraption (by today's perspective) that can reduce the cost of space travel by factors of 100. It seems like you have a great handle on the realities and problems of space elevators. But I think you should apply some of that skepticism to the Lofstrom loop as well. Its quite a stretch to say maintaining 7850 cubic meters of iron moving at 14 km/s is something we can do today.
This falls under a certain /. post category. In summary: An infant technology that gets a ton o
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Aww, my stalker is back! Hi, stalker!
Don't you have some nutters over at the USGS [wiley.com] to argue with? Damned USGS and their pie-in-the-sky analysis that is pretty much exactly what I wrote a couple weeks ago concerning resource availability and work/uncertainties that remain to be resolved! Given that this is what led you to start stalking me, you might want to split your time with stalking them too.
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Science works by peer-review. There's ample peer-review on the topic. If the word "nutter" has any meaning, it's "people who refuse to accept peer-reviewed science."
And obsessing over past interactions with people and following them around (including mentioning them in places where they're not even involved in the conversation) is otherwise known as cyberstalking
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Yeah, how is this different to nanotubes
That was my first thought.. it's just packing the carbon atoms tighter together... big deal.
BUT WAIT! **marketing team thinks furiously**
"Let's call them 'diamond threads' to generate the layman interest in news headlines and also to make them sound more expensive so we can charge more for industrial applications!"
Arthur C. was right again... (Score:5, Interesting)
In The Fountains of Paradise, Arthur. C. Clarke wrote about the use of a diamond filament for building the space elevator. The main character, Dr. Morgan, carried around with him a retractable rope made of this filament. He uses it at one point to climb down a cliff face, and it's so thin it can be barely seen...
Kudos, Arthur...
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In The Fountains of Paradise, Arthur. C. Clarke wrote about the use of a diamond filament for building the space elevator. The main character, Dr. Morgan, carried around with him a retractable rope made of this filament. He uses it at one point to climb down a cliff face, and it's so thin it can be barely seen...
Kudos, Arthur...
And when Morgan realized space elevators could be deployed all over the earth by linking them in a grid in space. Great book, you should check out the NAIC study on the space elevator, it is an equally interesting read.
Are we 50 years after everyone stops laughing yet?
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...you should check out the NAIC study on the space elevator, it is an equally interesting read.
Are we 50 years after everyone stops laughing yet?
It is an interesting read, and this study shows that material strength is required that does not exist in any prospective nanotube material. Their design requires operating at 50% of the theoretical limit of nanotube strength. This level of performance will never be achieved in any substantial cable.
Right now, after 30 years of work, 1 mm long nanotube cable samples just barely break 1% of the theoretical strength. Increase strength 50 times, length of a factor 40 billion, and cross section by a factor of a
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If it's so thin, it would slice through your hands if you ever tried to tie it off let alone hold onto it while you descend.
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If it's so thin, it would slice through your hands if you ever tried to tie it off let alone hold onto it while you descend.
Not if you wore gloves made out of woven diamond nanothreads.
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IIRC, there was a hook attached to it so you didn't need to tie it off anywhere, and you held onto the box that it was coiled up in...
Two questions before I invest (Score:1)
It sounds wonderful, but I have two questions before I book a ride...
How many cubic kilometres of material are needed to build the space elevator?
Will it turn into a pile of dust if it's hit by lightning?
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Will it turn into a pile of dust if it's hit by lightning?
The original NIAC study on the space elevator [nss.org] dealt with issues such as lightning, corrosion from atmospheric acid and oxygen, micrometeor strikes and aircraft exclusions zone. It also dealt with the mass required to anchor it, proposed how it would be built and which areas in the world would be suitable for the first one.
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Does it deal with the "person with an RPG or bomb vest" issue?
Hell, does it deal with the bird issue?
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It was funny for a little while, btw.
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Nonsense (Score:3)
They are not even close to sufficient in weight bearing capacity for an earth space elevator. Nothing we have is within 3 orders of magnitude of being sufficient. Not even in the smallest testable quantities. Now, we can build a space elevator on the moon. But not from earth.
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They are not even close to sufficient in weight bearing capacity for an earth space elevator. Nothing we have is within 3 orders of magnitude of being sufficient.
Well, you know, aim for the stars and you might end up with a wire that has some neat industrial applications.
Exactly! A S.E is a great thought experiment in what would it take to build one however even if we can't get that far having such a material for building and making things would probably introduce a new industrial revolution. We are still a long way off that though.
Slicey Dicey!! (Score:1)
... strongest material ever made. (Score:3)
At some point in time also a spider silk was the strongest material - stronger than steel. But I have yet to see a crane that uses spider silk to lift containers.
Wake me up when we can create a 1km long and 1cm thick rope from these diamond nanothreads.
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Stronger than steel per kg. Cranes don't really care too much about the cable's mass so they use steel, which is strong, cheap, plentiful and heavy. If they did care, they'd use any of several synthetic fibres that are much stronger by mass than steel. In space elevators, cable mass is the major limiting factor.
No no no no (Score:2)
Not News...yet. (Score:1)
Come back when you've made 2 metres....
Terrible Space.com Article: Here is a better one. (Score:2)
The summary links to a lousy article that says essentially nothing about the actual research. Here is an account that describes the material under study [psu.edu].
Space elevator for mars (Score:2)
Would diamond/carbon nanofibers be sufficient for a mars or lunar space elevator?
Are there any designs for such an elevator... (Score:1)
Oh great now I have to worry about shigawire. (Score:1)
Seriously. This will be the first published use of the material.
Re:How does space elevator save energy? (Score:5, Insightful)
How exactly does a space elevator "save" energy for lifting loads to orbit?
The same way using a ladder saves energy over using a jetpack.
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Sure, but now you're proposing a ladder that masses a billion times or more than the house, needs materials that theoretically may not even exist, requires co-operation at a planetary level that has never happened before, has been talked about for half a century and you don't even have even a single shred of a ladder yet.
Compared to that, jet packs exist, they are manufacturable, don't require magical materials, and they have been around for half a century rather than talked about.
So painting a house with a
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This is the longest "Oh yeah? Yo momma stinks!" post I have ever read.
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I was asked how they would save energy, and that's all my answer covered.
Re:How does space elevator save energy? (Score:4, Insightful)
The person you heard that from was wrong.
In a rocket,:
- Rockets are quite inefficient, about 16% energy efficient to reach orbit.
- You have to lift your propellant, only to throw it all away
- The rocket not only has to do work against gravitational potential, it also has to provide lateral kinetic energy to reach orbit. The kinetic energy component is huge.
For a space elevator:
- The lifting motors are highly efficient, you just have to keep the power beaming losses reasonable.
- You only have to work against gravitational potential. The tether/earth provides the lateral kinetic energy.
Re:How does space elevator save energy? (Score:5, Informative)
Your post is simply incorrect.
1) Rockets are not "quite inefficient". Their Carnot efficiency is usually 80%, net propulsive efficiency around 70% - way better than a gasoline engine (~35%) or diesel engine (40-45%). What they suffer from is totally different: the rocket equation. This mandates exponentially increasing fuel needs to reach a given delta-V, with the exponent proportional to the ISP. But fuel costs have nothing to do with how expensive today's rockets are, we're nowhere near that limit. The Space Shuttle consumed about $2m of propellant to deliver 25 tonnes to LEO, or $80/kg. Using electricity at 100% efficiency and $0,80/kWh it would cost about $0,80/kg to reach orbit. Today's launch costs are about $5k-10k/kg for large launches (the Shuttle was said to be about $18k). So you can see that the fuel costs are just the tiniest fraction, and that it's the engineering challenges of cost-effective production and reuse that are the issue.
2) The "keeping power beaming losses reasonable" is the problem the parent was describing. There is no known way to efficiently transfer power to a small object over tens of thousands of kilometers. Direct transmission isn't even close with conventional conductors, a superconducting line would be many orders of magnitude too heavy, and the cable itself would not be a superconductor, and even if it were its cross section would be way too low. Batteries don't cut it in terms of energy density. And the requirements that climbers be very light precludes nuclear except for the most unrealistically-massive of space elevators. To make RF power beaming remotely efficient over such distances requires a receiving antenna taking up dozens of square kilometers. Laser power beaming means receiving end (solar cell) losses (which even if the solar cells are tuned to a particular frequency you're unlikely to do better than maybe 30-40%) and laser losses (high power lasers are generally in the ballpark of 0,1% efficient; diode lasers can reach up to 25% or so but have far too poor beam quality and are way too weak to be practical). And of course you need a frequency that minimizes atmospheric losses at that.
Perhaps some day power transmission over those distances might become practical, but today it isn't.
This is just the very start of the problems with space elevators, of course. I know space elevators make great books, but they're not practical in the real world. Look into actively suspended structures for your "direct climb to space" needs. They're buildable with today's materials and can get greater than 50% efficiency in energy transfer.
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You don't need energy in the elevator. Simply have two elevators and a pulley wheel at the top. Lifting something then is just a matter of capturing some space junk or asteroid of suitable mass and lowering it in the other elevator.
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Calculate the mass of your cable. It doesn't work.
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And you plan to propose a rotating cable that somehow maintains its original taper as it rotates how, exactly? As soon as you start rotating it, the thick part will begin moving downward and the thin part upwards. At the bottom of its rotation it's precisely the inverse of what you need.
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It's a lot more fundamental than that. Even with 120 GPa unobtanium they still can't support themselves over those sorts of distances - any cable has to have a large taper factor (the lower the breaking strength, the larger the taper factor is needed). Which makes moving cables impossible, because as soon as you rotate it, the taper is structured all wrong - it has to constantly be thickest at the top and thinnest at the bottom or it will break.
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You don't need energy in the elevator. Simply have two elevators and a pulley wheel at the top. Lifting something then is just a matter of capturing some space junk or asteroid of suitable mass and lowering it in the other elevator.
Holy crap you have just invented a perpetual motion machine! That'll show the doubters.
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Wrong again. There's gravity everywhere, including GEO. There's no effective gravity in any orbit because the gravitational force is counteracted by your motion caused by inertia: you're in constant freefall when you're in a stable orbit, so it appears to be zero-g in your reference frame, even though it really isn't.
But there is gravity in GEO, and theoretically to the ends of the universe, all caused by Earth's mass: just look at the gravitational equation, there's no distance limits on it. Of course,
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You would use solar as your primary means of propulsion, and probably a secondary system for use inside the atmosphere. Current solar cells would be good enough to get you up to say 100km/h with reasonable load. At that speed it would take a couple of weeks to reach the top of the elevator, or less if you just wanted to get into LEO. Speed isn't that important when hauling cargo though. The array would be fairly large, like ISS large, but outside the atmosphere that isn't a problem.
Inside the atmosphere you
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Solar cells may produce - on a clear day - 200W/m^2, if they're sun-tracking and unshadowed. A climber climbing over the course of two weeks (more on that in just a second, you need to climb far faster) has to climb 35,5 meters per second. A small 1 tonne climber with 2 tonnes of cargo requires 1 megawatt of power, meaning 5000 square meters. Think you can fit 5000 square meters of sun-tracking solar cells on a climber that only weighs one tonne?
Speed is important because it defines throughput, and your cab
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1MW for a 3000kg climber? That seems rather pessimistic. I was using 2.4MW to lift a 20,000kg climber. That's achievable with multiple pulsed lasers and AlGaAs photovoltaic cells covering a reasonable area. You could expect 60% efficiency at that level, hitting about 55W/cm2 or more. Remember that PV efficiency goes up as the light gets brighter, and I think that there are actually better types of PV now anyway.
You would start off with a ground based laser, and then move to in-orbit lasers as you get higher
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What do you mean "you were using"? Gravitational potential energy at Earth at sea level is 9,81 * ChangeInAltitude * mass. 35,5 m/s * 9,81 * 20000 = 7MJ/s = 7MW. If you "were using" 2,4MW then you were only climbing at 12,2m/s meaning your entire trip takes 41 days - over a month. Which means that your elevator has laughably worthless throughput. And 20k kg climber requires a massive elevator massing millions of tonnes *with* unobtanium. So you're proposing to launch millions of tonnes of unobtanium to
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59% .... http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=122385&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D122385 [ieee.org]
That's the result of a quick search. I have no idea what the practical and theoretical limits are.
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Space elevator and Low Earth Orbit are not a particularly good match. Most of the energy needed to get into low earth orbit is to gain orbital velocity, the elevator is contributing mostly altitude.
Space elevator to LEO would work something like this: Vehicle is lifted on the elevator to about 100 miles, detaches from the cable and then uses rocket motors to boost speed by about 15,000 mph -- all without damaging the cable as the vehicle maneuvers rapidly.
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No, I mean $18k. From your link:
The $60k is when you include the cost of the whole program (including the design/development phase) which no figure in my post included. If you want to compare, you need to compare equivalent situations: the incremental cost per launch. And the incremental cost per launch of the Shuttle was an esti
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I hope everyone notes though: energy cost $80/kg, launch cost (at least) $18,000/kg.
Talking about "energy costs" shows rank amateurism when talking about space flight. Virtually the entire cost is the flight hardware and ground support infrastructure. Energy costs aren't even rounding error on those.
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Wow, it's almost as if my original post didn't read:
The "rank amateurism" here is in your reading comprehension.
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You only have to work against gravitational potential. The tether/earth provides the lateral kinetic energy.
Any cargo climbing to the upper floor would need to gain a proper orbital velocity. It might get it from the ground or from the upper floor or from its own engine. It means that you would need to provide some fraction of the lateral kinetic energy by accelerating laterally either the cargo or the upper floor.
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But what if the elevator carried some extra mass and shot it out sideways as it went up, to take advantage of the slingshot effect?
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The downward trip can actually generate electricity.
Also, the fuel can be whatever you want. A lot of these fuels are a lot cheaper than disposable tanks of rocket fuel.
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People claim all sorts of things. While there are lots of problems with a space elevator on a world as large as Earth, energy efficiency isn't one of them.
Personally, I doubt that a space elevator will ever be practical on Earth, but it should be on Mars, and it definitely would be on the Moon. For Earth I'd favor something like the pinwheel. You can think of the pinwheel as a rotating space elevator that doesn't reach as far down as the ground. (You'd probably want to not reach further down than the up
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That's the reason that the first thing you'd do with a working space elevator, is to build another space elevator right next to it.
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Space elevator can actually produce its own electricity (and a lot of surplus) from Earth's magnetic field, so the energy requirements are essentially null.
The problem is that any "crawler"/"lift" would be limited to maybe 300km/h speeds optimistically, and as result take a month to reach GEO. And due to tensile strength limitations, only one payload at a time could travel. So while yes, that would be extremely cheap in terms of $/ton to orbit, the throughput, tons/month to orbit would be extremely limited.
What is our current throughput? If you only count the cargo and not the rockets, I doubt all launches combined even average a single ton per month and at considerably higher cost per pound. I don't see this as a limiting factor as it's a lot better than we currently have. If it becomes a limiting factor then that means that it is constantly full and bringing in plenty of money so we need to just build a second or third one.
The bigger problem I see is the threat of damage and/or sabotage. Ideally you wou
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There have been 69 successful launches this year:
https://en.m.wikipedia.org/wik... [wikipedia.org]
Which doesn't mean anything without a payload capacity. Many of those launches appear to be cubesats and other small payload launches. That being said, I did find that the ISS resupplies are about 2 ton so if the space elevator really did only have an equivalent fixed 2 ton capacity and a fixed 30 day roundtrip then it would be the equivalent of only 12 ISS resupply trips. Hopefully we could over time increase the number(frequency) of cars, the capacity of the cars, and the speed of the cars.
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Let's see...a month at 300km/hr takes you 216000 km. Do you really think GEO is almost as far away as the moon? Or are you just arithmetically challenged?
Hint: at 300 km/hr, GEO is about five days away....
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Excellent.
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You mean like how a bed of nails causes all the nails to penetrate extra deeply? How snowshoes cause the feet to sink extra deep in the snow?
Just...no.
Excellent point. Also: the technique of weaving fibers into a mesh that does not pull apart (essential for soft ballistic protection) is well developed.
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Go lie on an elevated bed of nails.
Then let someone fire a gun at at the nail heads beneath you.
When the material is so thin, instead of it spreading the force out to support your meatflesh, your meatflesh ends up supporting the material (by being sliced and diced). You need to carefully weave these materials in layers or apply some other layer to actually distribute the force before it gets to you. Both options make them heavier, thicker, and less flexible. Making the material thinner and stronger is WOR
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You add a layer underneath tuned to complement the top layer. For instance in this case designed to help spread the inertia of the bullets kinetic energy across the material. There's a new gel material that apparently does exactly that - shock solidifies it and it momentarily becomes almost as hard as steel..
Re: (Score:2)
As the thread gets finer, so does the mesh. Pressure remains constant when thread diameter and mesh spacing change in sync.
The problem is that thin chain mail will not distribute impact well, and thickness achieved with multiple layers helps that.