Diamond Nanothreads Could Support Space Elevator (space.com)

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.

Comments

First post!

[Anonymous Coward]

Suck it, nubs.

Kim Stanley Robinson

[at10u8]

time to re-read Red Mars

Re:Kim Stanley Robinson

[Anonymous Coward]

Different author but... don't forget "Diamond Age"

Re:Kim Stanley Robinson

[Tomahawk]

And The Foundations of Paradise, Arthur. C. Clarke.

Re:Kim Stanley Robinson

[Anonymous Coward]

Clarke's science > Robinson's science.

For a large factor of >.

Re:Kim Stanley Robinson

[trabby]

It will still be 50 years before it is built as everyone still laughs at it.

Re:Kim Stanley Robinson

[Crowd Computing]

And The Foundations of Paradise, Arthur. C. Clarke.

I think you meant Fountains of Paradise. Another sci-fi great, famous for his three laws of robotics, did write something called the Foundation trilogy. A space fountain 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.

Re:Kim Stanley Robinson

[Tomahawk]

Annoyingly, in a post I typed previous to this one, I put Fountains... bloody fingers.

Re:Kim Stanley Robinson

[Crowd Computing]

Yes, space elevators could become the Foundation of a space utopia, if we can only get them off the ground.

Re:Kim Stanley Robinson

[wiggles]

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.

Re:Kim Stanley Robinson

[Anonymous Coward]

We aren't waiting for people to stop laughing, people are laughing because it's a laughable non-starter of a daydream.

Re:Kim Stanley Robinson

[Anonymous Coward]

You wouldn't know communism if you were planting potatoes in a collective.

Re:Kim Stanley Robinson

[Anonymous Coward]

There is no "space utopia". What kind of delirious delusional nonsense is that anyways? Russian Cosmism was just another failed cult.

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

http://www.theatlantic.com/technology/archive/2012/03/the-holy-cosmos-the-new-religion-of-space-exploration/255136/

Re:Kim Stanley Robinson

[RockDoctor]

While I've definitely liked some of KSR's work, Red Mars was tedious enough to put me off the rest of that Cycle. I'll not cross him (or is it a she - I can't remember, and can't be bothered to look it up) off my reading list. But the Mars cycle isn't going to get me at the bookshop again.

But

[penguinoid]

Will it last forever?

Re: But

[Anonymous Coward]

Yeah, how is this different to nanotubes

Re:But

[davester666]

yes. just keep wrapping it around her neck, tighter and tighter...

Re: But

[Rei]

From the perspective of a space elevator, it's not. Read this paper 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?

The yield strength experienced more than 25% reduction (from ~ 75 GPa to ~ 56 GPa) for the DNT-14 when the sample length increases from ~ 13 nm to 26 nm. Afterward, it fluctuates around 56 GPa. Unlike the yield strain, the yield strength for all considered DNTs saturates to a similar value (around 56 GPa) and exhibits a relation irrelevant with the constituent units for the investigated length scope (fro ~13 - 92 nm)

  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 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 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.

Re: But

[Anonymous Coward]

You mean Nutter bait.

"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."

But mining asteroids makes perfect sense, based in facts, reality, and engineering feasibility.

Re: But

[dotancohen]

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.

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 /. 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 people knowledgeable in specialized fields to weigh their opinions on the subjects. Adding speculation to the summary preempts the knowledgeable from properly examining the issue, and gives the trolls a foot hold from where to start derailing the discussion.

Re: But

[Rei]

Aww, my stalker is back! Hi, stalker!

Don't you have some nutters over at the USGS 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.

Re: But

[Grishnakh]

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?

Re: But

[Anonymous Coward]

Don't flatter yourself, you're just one of the Space Nutters on here. You're not as bad as say, Applehu, but still delusional.

And your appeal to authority argument isn't very impressive.

It's very simple. Extraordinary claims, of which Space Nutters have an infinite supply, require extraordinary evidence, which Space Nutters never have.

Re: But

[Anonymous Coward]

Hey, speaking of my list of delusional Space Nutters, it's the King himself!

How about Ganymede? You know, if we're going to talk about impossibilities and utter fantasies?

Re: But

[CaptainLard]

We'd do far better to direct such efforts to more realistic access methods, such as a Lofstrom loop 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 of hype despite seemingly insurmountable challenges is crap whereas a totally un-hyped infant technology will solve all our problems if we'd all just take a look (see: thorium reactor, any number of alternate fusion containers, etc).

Re: But

[Rei]

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

Re: But

[Anonymous Coward]

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.

Re: But

[Anonymous Coward]

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 technological limitations but because laws of physics say "no".

Re:But

[R3d M3rcury]

...and how will we get it down?

Re: But

[Anonymous Coward]

Science is one thing. Building something is quite another.

Allow me to demonstrate:

I just set up a spreadsheet. I called one cell "hourly wage". Another cell is "hours worked". The third cell is the multiplication of the first two cells.

You could argue that mathematically, it is valid. You could even get economists to agree.

Now what is the upper limit, IN REALITY, for the first two cells?

If I put in a million dollars for the hourly wage, am I allowed to say "but it's math! It's been reviewed by economists!" when someone points out it's not possible?

That's where you are. You have a spreadsheet, all the formulas are correct, but you don't know how to use them.

"is otherwise known as cyberstalking"

No, it's not. Otherwise the whole Internet, including those references at the end of your science papers, is "stalking". I notice there are people with rabid, delirious, infantile beliefs. I feel bad for them, and don't understand how they ended up at the million dollar cell stage of their reasoning.

And note, I did try to use a login name, but this being the group think masturbation central, the first post I made criticizing the mindless space delusions got nuked into bad karma. So what's the point?

Also I can't help my unreasonable memory. I remember things clearly back to when I was 4. Remembering a few names of people with bizarre, eccentric views is not difficult.

Re: But

[thoughtlover]

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!"

Re: But

[scdeimos]

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:

• Diamond Nanothreads Could Support Space Elevator [2015-11-23]
• Diamond nanothread rivals graphene as the next big wonder material Now scientists want to build a space elevator out of it. [2015-11-27]
• We may soon be riding up to space in style in elevators made of diamonds [2015-11-23]
• Our Future Space Elevator May Be Built of Diamond [2015-11-21]
• Diamond Nanothreads Could Support Space Elevator [2015-11-19]
• Scientists Say We Could Build a Space Elevator Using Microscopic Diamond Chains [2015-11-19]

Re: But

[Grishnakh]

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?

Re: But

[dotancohen]

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!

Re: But

[dataspel]

"Active suspension via recirculating kinetic transfer" Provide a link please? Not even sure what this phrase means.

Re: But

[ChrisMaple]

Has it not occurred to you that the peer of a fool is another fool?

Re: But

[Anonymous Coward]

You enclose the diamond fibers inside the nanotubes, then wind the nanotube enclosed diamond fibers into larger cables before winding those into even larger cables. Once the cable is lifted by rocket and then slowly descended from near earth orbit and anchored deep into the earth's crust, you must begin the process of affixing resilient stainless steel track plates for the vehicle to travel up and down. Go ahead and budget for additional cables to maintain the integrity of the system.

Alpha centauri was right

[Anonymous Coward]

You have to research super tensile solids first

Re:Alpha centauri was right

[Anonymous Coward]

No. Haven't you heard? Must send someone to Mars first. It's the only way to survive the asteroid that hit in the the Earth next 100 years.

Sure

[Anonymous Coward]

So all we need to do now is launch a gigabillion tons of diamond nanothread cable into high orbit, anchor it to an asteroid or comet we diverted to a stable Earth orbit earlier and start lowering the cable. Or if we mined the anchor and produced the cable in-orbit, this would be just like Red Mars, yay!

How does space elevator save energy?

[Anonymous Coward]

I've heard someone claim that the energy requirements (and transmission loss) to lift something up a space elevator did not compare favorably to rockets. Still, many seem to have high hopes for the concept. How exactly does a space elevator "save" energy for lifting loads to orbit?

Re:How does space elevator save energy?

[wonkey_monkey]

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.

Re:How does space elevator save energy?

[aXis100]

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?

[Anonymous Coward]

The net-Joules required seem to be turning out to be not as good as imagined foe

Re:How does space elevator save energy?

[Rei]

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.

Re:How does space elevator save energy?

[Anonymous Coward]

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.

Re:How does space elevator save energy?

[art6217]

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.

Re:How does space elevator save energy?

[towermac]

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.

Re:How does space elevator save energy?

[91degrees]

You don't need to lug several times your payload's weight into orbit as fuel.

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.

Re:How does space elevator save energy?

[Anonymous Coward]

Except how many thousand tons would you need to lift? At 1 ton/month?

Re:How does space elevator save energy?

[Wycliffe]

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 would have a system that could self-repair if it broke or at least safely descend and have a way to quickly be repaired and redeployed. If you had lightweight 1km segments that if disconnected could retract and safely float down that might be ideal. Even if you needed to use a rocket/shuttle to launch all the segments back to orbit and then lower them again with the space hook, this would be considerably cheaper than having to rebuild it from scratch if something happened to it. Not to mention the danger of a huge cable circling the globe.

Re:How does space elevator save energy?

[Anonymous Coward]

The Space Shuttle consumed about $2m of propellant to deliver 25 tonnes to LEO, or $80/kg.

I think you mean $60k/kg, Criticism of the Space Shuttle program

Re: How does space elevator save energy?

[Anonymous Coward]

There have been 69 successful launches this year:
https://en.m.wikipedia.org/wiki/2015_in_spaceflight

Re:How does space elevator save energy?

[Anonymous Coward]

Any cargo climbing to the upper floor would need to gain a proper orbital velocity.

I think all concepts of space elevators assumes the elevator itself is in geostationary orbit in some way or another. Otherwise it will be "impractical" to start the climb.
Climbing the elevator will gradually put you at orbital velocity.
Either the endpoint is in geostationary orbit with a ballast extending outwards that provides enough pull to keep the cable to earth from pulling it back down or it has the midpoint of the cable in geostationary orbit which means that anything that climbs the full length will be well over escape velocity when it "drops" off the endpoint.

Re:How does space elevator save energy?

[hippo]

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.

Re:How does space elevator save energy?

[Anonymous Coward]

Have you even attempted to read carefully, what the two preposters said?

Re:How does space elevator save energy?

[Rei]

No, I mean $18k. From your link:

by 2011, the incremental cost per flight of the Space Shuttle was estimated at $450 million,[3] or $18,000 per kilogram (approximately $8,000 per pound) to low Earth orbit (LEO).

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 estimated $18k/kg.

Re:How does space elevator save energy?

[AmiMoJo]

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 could beam power from the ground. It would still need advances on microwave beaming technology, but not unreasonable ones.

Re:How does space elevator save energy?

[Anonymous Coward]

Or from tension of the elevator.

If you swing a rock on a string around your head, the rock doesn't need a rocket engine.

The cargo inertia will make the elevator trail behind Earth rotation a little bit, then the centripetal force at the counterweight will straighten it again (at cost of minimally slowing down the Earth) and give the cargo its orbital speed.

Re:How does space elevator save energy?

[Anonymous Coward]

There is no gravity in orbit, nub. A space elevator's anchor would have to be so far away that the point where gravity actually kicks in would be negligible. You also don't seem to have the basic understanding of long cables: skyscrapers don't have cable elevators because they would in effect be just huge yoyos. An elevator cable spanning tens of thousands of kilometers is not doable in any way you look at it. Not only would the cable have to be insanely long, it would also need to be extremely durable, flexible and light.

Re:How does space elevator save energy?

[Anonymous Coward]

There is no gravity in orbit, nub.

Wow, you really don't have a clue!

Yes, there is gravity in orbit

Re: How does space elevator save energy?

[Wycliffe]

There have been 69 successful launches this year:
https://en.m.wikipedia.org/wik...

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.

Re:How does space elevator save energy?

[Anonymous Coward]

There is no gravity in geosynchronous orbit. But in low earth orbit, gravity exists for things not traveling at 17,500 mph (or whatever it is). It is a little less, but it's there

Re:How does space elevator save energy?

[Rei]

Calculate the mass of your cable. It doesn't work.

Re:How does space elevator save energy?

[Rei]

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 cables - even if you have some mythical unobtanium 100-120 Gpa diamond filament tether - are still very massive objects with very tiny objects climbing them, meaning you need high throughput to make them economically justifiable.

I don't think most people discussing space elevators realize how tiny the margins on these things have to be even with a cable made of unobtanium. Inside the atmosphere is irrelevant. It's the tiniest fraction of your 43000 kilometer trip, you have no margin to make a special case for in-atmosphere propulsion. It's only relevant for the additional problems it causes your cable, such as wind, lightning, ice, oxidation, etc.

Space elevators really aren't a good design. They're just totally impractical even when made of unobtanium. But science fiction has locked a generation onto this concept when there are far better concepts available.

Re:How does space elevator save energy?

[TheRaven64]

No space elevator designs that are even vaguely plausible include a moving cable. To understand why, consider the mass of such a cable: the energy required to accelerate it and then decelerate it for the cars to start and stop would be phenomenal. You could potentially have a loop that would continuously move in a circle, but you'd still have problems starting it. Just dropping things from the top wouldn't be enough, because you'd need to get them a fair way down before they'd stop orbiting and actually provide force in the correct direction. I don't even want to think about the lateral forces that such a structure would have to endure.

Re:How does space elevator save energy?

[AmiMoJo]

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 up.

Economically the construction cost will be huge, but once you have one you can build more relatively cheaply because it costs very little to get mass into orbit. You could also do a lot of other projects, like massive in-orbit solar arrays that beam power back to earth via microwave link, or building very large space stations etc. so you might be able to amortize the cost. You have to think of the new things you could do, not just assume competition with existing satellite launch systems.

Speed isn't a huge problem if your cable can support multiple climbers. The cable is the difficult part, power transfer is solvable with current technology.

Re:How does space elevator save energy?

[Rei]

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.

Re:How does space elevator save energy?

[thinkwaitfast]

You want to talk joules(energy), not watts. And the energy requirement is ~33MJ/kg

Re:How does space elevator save energy?

[CrimsonAvenger]

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.

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....

Re:How does space elevator save energy?

[Grishnakh]

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, the effect of gravity diminishes with distance and it competes with the gravity caused by other bodies so past a certain point it becomes negligible. But for a practical example, the Moon exerts significant gravitational force on the Earth, which is what causes our tides, and the Moon is much farther away than GEO.

Re:How does space elevator save energy?

[careysub]

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.

Re:How does space elevator save energy?

[Anonymous Coward]

Calculate the mass of your cable. It doesn't work.

Umm, that might be true if the concept relied on cables. Since it relies on ribbons woven in specific and differing ways based on height you might want to actually know something about which you are talking, as clearly you don't.

Re:How does space elevator save energy?

[Rei]

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 GEO in order to send a fraction of 20tonnes up once every 41 days? Good luck with that.

You could expect 60% efficiency

That's exceedingly optimistic even for monochromatic light (which I see we're back to discussing). Have you ever priced the sort of Spectrolab cells you're proposing here? And anyway the highest monochromatic conversion rate ever recorded - lab scale - was 53%.

Remember that PV efficiency goes up as the light gets brighter

Only when you can keep the cells cooled to the same ambient temperature (and it's only a relatively small gain). How exactly do you propose to ditch megawatts of waste heat up there? Heat is a killer to solar cell efficiency. And several megawatts shining on a relatively small area is otherwise known as "vaporizing it".

No comments about the 0,1%-ish efficiency of the sorts of lasers that actually have the coherency and power to beam over such distances, I see. Even over the distances of your "in-orbit" lasers, of which apparently you want there to be hundreds of thousands if you want to ensure that there's one close to the tower at all altitudes at all points in time. Hundreds of thousands of multi-megawatt lasers each consuming a gigawatt or so of power. In order to launch a fraction of 20 tonnes to GEO once every 41 days. Great strategy.

Economically the construction cost will be huge, but once you have one you can build more relatively cheaply because it costs very little to get mass into orbit.

There is nothing "cheap" about what you're proposing. Your capital costs are nonsensically high, and you have to pay interest on capital costs if you want to live in the real world, and interest accrues interest. You will never, ever reach an economically valid argument for it. And for what gain? If you're turning $0,08/kWh industrial-rate grid electricity into climbing power at 0,05% efficiency then you're paying $160/kg to get to orbit, several times the price to orbit of what's possible with a rocket if it can be made reusable with minimal turnaround costs between flights (as mentioned earlier, the Shuttle's propellant cost to orbit was only $80/kg, most of that in the SRBs, which aren't the cheapest of propellants). And of course it's not even close to a Lofstrom loop, which can be made without unobtanium and deliver payloads at an energy cost to orbit of about $1,60/kg, with present tech.

Speed isn't a huge problem if your cable can support multiple climbers.

So you want to make your cable even bigger, heavier, and more expensive. How many times more expensive do you want to make it? 5 times? 10 times? 100 times? Why not just say that your cable is going to be the mass of the moon's worth of unobtanium while you're at it?

And again, we're only talking about the most basic of problems with space elevators here, let alone actually getting into the countless engineering problems, some of which have no known solutions, and none of which you really have a mass safety margin to properly address. The resonance issues are some of my favorite ones: from the climbers, from the atmosphere, from the sun and from the moon. You have a giant cable which has basically zero ability to damp itself, and no mass leeway to install any sort of damping system of the sort

Re:How does space elevator save energy?

[Rei]

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.

Re:How does space elevator save energy?

[Rei]

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.

Wow, it's almost as if my original post didn't read:

. 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.

The "rank amateurism" here is in your reading comprehension.

Re:How does space elevator save energy?

[Anonymous Coward]

You clearly know a lot about rockets. I am guessing you work in the industry, but you also clearly know fuckall about space elevator concepts from your comments.

The tether would not be a cable or cables, but a ribbon woven specifically and differing with height. Power beaming to LEO is in the hundreds of kilometers, not "tens of thousands of kilometers" range, with power transmission coming from the ground for half that distance to three-quarters for safety. Power would come from the LEO platform for the second half of the upward journey.

You also talk about the weight of the tether as if it needs to be free standing. No viable concept uses a free standing cable. There has to be a geostationary mass at the other end in space with a platform somewhere at LEO distance. It's the tension on the tether ribbon that has to be accounted for more than anything, that and capturing an appropriate mass for the geostationary end. We'll have a material that will be capable of being light and strong enough in a few decades if the research continues. So, not only are we talking about what we'd need to build the tether and power a crawler, we're talking about capturing an asteroidal mass for use as a tensioner. These are things that are decades if not a century away, but not untenable.

You are correct that current technologies for achieving LEO with a space elevator are untenable, but we're not talking about building one tomorrow. It will take two or more generations at least before the tech comes up to speed with the concept and since technology doesn't proceed at a linear rate but makes large leaps forward that two generations is a conservative estimate. This isn't something we cannot achieve, but it will take a while. Just because it will take generations to get there doesn't mean we dismiss the idea out of hand and act short sightedly, as you seem to want to do.

Sure, rockets are what we have now, and making the cost of using them go down is a valuable pursuit, but not at the cost of finding a way to replace them with something better. Look how far we've come with the concept since Arthur C. Clarke wrote about it (1979), and Yuri Artsutanov came up with the modern concept (1959).

Re:How does space elevator save energy?

[Anonymous Coward]

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 jet pack makes orders of magnitude more sense than your disingenuous comparison to a ladder.

Re:How does space elevator save energy?

[advocate_one]

because the potential energy of an object coming down can be used to raise the potential energy of an object going up...

Re:How does space elevator save energy?

[Impy the Impiuos Imp]

This is the longest "Oh yeah? Yo momma stinks!" post I have ever read.

Re:How does space elevator save energy?

[Impy the Impiuos Imp]

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?

Re:How does space elevator save energy?

[HiThere]

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 upper stratosphere to minimize frictional losses.) You fly up to meet the descending arm at the bottom, and unload cargo onto it. Descending cargo can be handled the same way, or you could use a combination of parachutes and lifting bodies. You need to balance freight going up and coming down or you get orbital decay...either it lifts too high or comes down too far, but this can be handled by a station keeping ion rocket, possibly of Vasimir design. Reaching a height is a lot cheaper than going into orbit. This does require a large orbital mass.

Re:How does space elevator save energy?

[wonkey_monkey]

I was asked how they would save energy, and that's all my answer covered.

Re:How does space elevator save energy?

[art6217]

I guess that if you would want the tether to become straight again, you would need to press the STOP button. The thing is, some elevators seem to miss that button for whatever reason.

Re:How does space elevator save energy?

[art6217]

Yes, you are right, the elevator would swing at most.

Re:How does space elevator save energy?

[tehcyder]

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.

Re:How does space elevator save energy?

[ChrisMaple]

And anyway the highest monochromatic conversion rate ever recorded - lab scale - was 53%.

59% .... http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=122385&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D122385

That's the result of a quick search. I have no idea what the practical and theoretical limits are.

Re:How does space elevator save energy?

[ChrisMaple]

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.

Re:How does space elevator save energy?

[Anonymous Coward]

You've heard somebody say huh? You are going to have to do better than that. The space elevator economics is an established field - Google it. We are talking about $200 per kilo for the elevator vs about $2000 per kilo for the Falcon Heavy.

Re:How does space elevator save energy?

[Stuarticus]

I guess a see saw must be one as well then, I'd better patent that.

Re:How does space elevator save energy?

[Anonymous Coward]

very simple problem to solve, had you seen how conventional elevators work (engine on top or bottom pulling cable attached to the cabin) we can do exactly same with space elevator, no need for it to have it's own power.

The cable strength and weight most likely will be huge, but when we can build cable strong enough for elevators to climb we should be able to do cables we can pull just as easy, in fact they can be much weaker that the one elevator is climbing.

Re:How does space elevator save energy?

[Anonymous Coward]

You assume that the cable is going to be not uniform.

Many also forget that effective mass (the mass that cable needs to support) of a cable as it gets away from Earth's gravity well is decreasing, so in total the cable need to be something like 50-70k km.

Let say first kilometre of the cable on Earth weight about 100 kg and therefore it adds 100 kg of effective mass.
Then 1 kilometre of cable at 6.4 km will add only 25 kg of effective mass.
Then at 12.8 km distance the cable will add only 6.25 kg of effective mass.
And so on.

Basically for every doubling of distance from Earth gravity pull becomes 4 times weaker.

Note: I do not know how think cable you need and how much 1 km of cable will weight, the example above is just for demonstration purposes. I assume the real thing will be much lighter.

Re:How does space elevator save energy?

[Anonymous Coward]

Thickest part will be not on the top but somewhere in between (GEO orbit I believe). The cable itself will have to go beyond that (counterweight), or the cable weight will drag the whole station down.

Also note that even in high buildings elevator cables are uniform (to my knowledge) therefore I do not see why this one should be not.

Re:How does space elevator save energy?

[Anonymous Coward]

It's funny how many people talk about unobtainium as if it is on the very blink of theoretical limit, or beyond it.

However, the strongest material we know about colossal carbon nanotubes can create cable 6,066 km long which will support its own weight.

Note that theoretical limit for materials is 9,200,000,000,000 km long cables that can support its own weight under Earth's gravity. So our materials science was not even born yet in terms of coming close to fundamental limits.

BTW if you take into account that gravity pull is reduced with distance from Earth, then back of the napkin calculations show that we only need material that can support 5,446 km of its own weight to build cable to geostationary orbit 36,500 km. I believe we need a bit more than that (counterweight) to build space elevator.

Basically already known materials are enough to build space elevator, we just need to improve purity and scale up the manufacturing. Cheers.

Re:How does space elevator save energy?

[Anonymous Coward]

Oh yeah, there is Used Data

Also calculations did not include centrifugal forces of Earth Rotation, which should have reduce necessary material strength even more.

Also if you place counterweight about 10,000 km away than it will add only 182 km to extra strength requirement, still well within available.

Arthur C. was right again...

[Tomahawk]

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...

Re:Arthur C. was right again...

[MrKaos]

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?

Re:Arthur C. was right again...

[MrKaos]

I knew it was around somewhere: www.nss.org:8080/resources/library/spaceelevator/index.htm

Re:Arthur C. was right again...

[careysub]

...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 million, and you are there.

People are going to be laughing for a long, long time yet.

Re:Arthur C. was right again...

[sexconker]

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.

Re:Arthur C. was right again...

[Anonymous Coward]

Arthur had a degree in Math and Physics from Kings College, London. FWIW, my father was a visiting professor of physics there in the 1960's. A first class school, and Arthur was a very smart cookie! I've enjoyed his work since the 1950's.

Re:Arthur C. was right again...

[tehcyder]

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.

Re:Arthur C. was right again...

[Tomahawk]

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...

Still not strong enough!!

[Anonymous Coward]

It's still not strong enough to support my girlfriends fat arse!!

State Penn, blah, blah, blah

[Anonymous Coward]

So State Penn researchers come up with a material that doesn't exist that can potentially support a space elevatorl blah, blah, blah. I didn't seen anything in the linked arxiv article that referenced sheer forces; nope, nada.

Just goes to show why they're chemistry professors and not physics professors.

Even a some random, drunk, asshole can see that shit.

Re:State Penn, blah, blah, blah

[Anonymous Coward]

Even a some random, drunk, asshole can see that shit.

Such as yourself, for example. Some of your words are un-intelligible, perhaps you should remove your head from your asshole.

Two questions before I invest

[Ferocitus]

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?

Re:Two questions before I invest

[MrKaos]

Will it turn into a pile of dust if it's hit by lightning?

The original NIAC study on the space elevator 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.

Re:Two questions before I invest

[Anonymous Coward]

i would search 'asbestos cancer mechanism' from google before investing anything.
I think i read some article years ago how thin threads induce cancer when inhaled. nothing to do with the chemical properties..

Re:Two questions before I invest

[Megane]

If you want more things to worry about before you "book a ride", the space elevator could take days to reach the top, during which time you have to slowly go through the wonderful Van Allen radiation belts. But maybe we will put up something to drain them of their charged particles by then. (in before all the people whining that draining the belts would somehow permanently remove them, or that the charged particles are the important part of the belts, rather than being the crap that they accumulate)

Re:Two questions before I invest

[sexconker]

Does it deal with the "person with an RPG or bomb vest" issue?
Hell, does it deal with the bird issue?

Re:Two questions before I invest

[MrKaos]

You COW.

It was funny for a little while, btw.

Nonsense

[samantha]

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.

Re:Nonsense

[Anonymous Coward]

Not entirely.

Even kevlar was reported to be able to be used - though not practical (the diameter of the cable at geosync orbit was a couple of kilometers, and only a millimeter at the surface - and took a huge amount of material).

Diamond bonding has been calculated before to be usable - the problem is manufacturing such long chains...

Re:Nonsense

[Anonymous Coward]

This is currently possible with nanotubes.

Caveat: the rope can't be equal thickness; it must be way thicker where the strain is the highest (GEO level) and narrowing down suffeciently that thicker upper part can support thinner lower part.

I remember finding some calculations that took nanotubes as the material and calculated the thickness needed to bear the rope plus 1 ton payload...

It was around 1km diameter at GEO.

Re:Nonsense

[Anonymous Coward]

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.

That is a nice thing with space elevator technology. Partial results will benefit society a lot, even if the elevator itself is a pipe dream.

Personally I think space elevator research is more worthwhile than robotic Mars missions. What I see coming from Mars robots is more robust communication protocols and to some extent autonomous driving, but the car industry is willing to fund the latter and aspires to deal with a lot more complex environment with a way lower economic cost of failure.

Re:Nonsense

[MrKaos]

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.

Re:Nonsense

[Anonymous Coward]

Uniform cable made of nanotubes of sufficient purity can easily support Space Elevator. You can make it as thick or thin as you want, it depends on how much mass you want it to be able to carry (beyond it's own mass).

love in an elevator! 3

[Anonymous Coward]

looks like meat's back on the menu, boys!

in the air!
in the air!

Slicey Dicey!!

[adrn01]

Super strong, super thin threads? Wasn't there a scene in Neuromancer where one of those, extended from a diamond spool worn as a thumb, constituted a deadly weapon?

... strongest material ever made.

[rastos1]

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.

Re:... strongest material ever made.

[Anonymous Coward]

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.

Wake me up when we have any "strongest material" rope big enough to see.

Re:... strongest material ever made.

[ceoyoyo]

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.

Re:... strongest material ever made.

[Anonymous Coward]

The trouble with spider silk is that spider farming is hard.

I'm not actually joking.

Screw the space elevator...

[Anonymous Coward]

I want a full suit of diamond nano-chain-mail.

Re:Screw the space elevator...

[Anonymous Coward]

Changing a simple stab/bullet wound into a wide, fine mesh of flesh sliced into microscopic strings as each fibre of the "chainmail" pulled by the bullet/blade cut deeply into your body.

Re:Screw the space elevator...

[Quatermass]

Excellent.

Re:Screw the space elevator...

[Anonymous Coward]

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.

Re:Screw the space elevator...

[careysub]

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.

Re:Screw the space elevator...

[Anonymous Coward]

I'd wager that they'd want a good mesh of the fiber, not just having strands dangle over their body.

My only thoughts about using the material for an elevator of any sort, are that diamonds are still carbon, what is the cost efficiency, and since the material isn't enough, has there been enough research into weaving patterns to help increase the strength of what ever the material of the month is?

Re:Screw the space elevator...

[Anonymous Coward]

We're not talking a bed of nails but a bed of needles. I wonder how good snowshoes are if you string them with the finest fishing line as well.

Re:Screw the space elevator...

[sexconker]

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 WORSE for armor.

Re:Screw the space elevator...

[Anonymous Coward]

For some reason you seem to be assuming it would be like "chicken wire" with big voids in between threads. More likely it would resemble thin, strong fabric or even a "film" with no discernible structure because it's so small. Depending on how flexible it is and how tightly or loosely it fits on your body, it could provide some protection. A bullet would pull the material into the wound, but if it doesn't stretch or tear it would not allow deep penetration or damage caused by fragmentation or deformation of the bullet - the energy would be dissipated on the area directly adjacent to the impact. This would still result in trauma, but at least the bullet would be easy to extract by pulling the fabric out of the hole (this occasionally happens with silk shirts). Against knives, a garment made of thin indestructable material would be great.

Re:Screw the space elevator...

[ChrisMaple]

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.

Re:Screw the space elevator...

[lucien86]

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..

No hard facts yet

[Anonymous Coward]

Original PSU article: http://science.psu.edu/news-and-events/2014-news/Badding9-2014
"Theory by our co-author Vin Crespi suggests that this is potentially the strongest, stiffest material possible, while also being light in weight"
It's definitely too soon to rejoice.
Also, "diamond thread" looks nice, compared to e.g. "benzene thread" right? :o

the next asbestos is here!

[Anonymous Coward]

long and thing threads cause cancer when inhaled even if they are chemically other vice OK. search 'asbestos cancer mechanism' or smth

No no no no

[ThatsNotPudding]

The dude who created Molecule Chain was named Sinclair!

Garrote

[Anonymous Coward]

You could make a cool garrote with one of those threads. Totally invisible

Not News...yet.

[Quatermass]

Come back when you've made 2 metres....

Re:Not News...yet.

[Anonymous Coward]

That's what she said.

Re:Not News...yet.

[Anonymous Coward]

I'd bet your ancestors may have said something similar to the Wright brothers and now look just as foolish. Baby steps. We didn't go from flying a few meters off the ground for tens of meters to the moon in a decade, but we did get there and threw egg on those that scoffed.

I like the idea, hopefully there is a plan

[Anonymous Coward]

I would hope that NASA, Roscosmos, ESA, JAXA, CNSA, and ISRO have worked up a plan for how to build it once a suitable material has been found.

I do like the idea of placing a large asteroid into geosynchronous orbit, and then have a smaller one descend. Gravity will ensure that it is being pulled tight and goes straight down. I also think that putting the space station at the end of it's life up there would help crews setup everything.

Well

[Anonymous Coward]

If you're packing a carbon nanotube, the only way you're getting a vertical ride is with diamonds. "She'll pretty much have to"

Terrible Space.com Article: Here is a better one.

[careysub]

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.

Elevator will happen when materials are proven

[Anonymous Coward]

Oh look, some decayed old Luddite butthurt. What's the matter, your buggy whip hanging up there useless, touching off some stank 'ol nostalgia for ya? protip - stop reading tech sites. You're too backwards to hang around real engineering types.

Re:Elevator will happen when materials are proven

[Anonymous Coward]

You do realize there are a lot of very serious engineering concerns, even if we find a magic material to make the Tether out of, right?

Re:Elevator will happen when materials are proven

[Anonymous Coward]

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.

Re:Elevator will happen when materials are proven

[Anonymous Coward]

Of course. You do realize that our history is replete with solving very serious engineering concerns, do you not? You do realize that when a huge economic benefit beckons, last one there is the one with the empty pockets? You do realize that engineers love challenges, right? Right?

Yes, it's all about the material. That's the key to it. Period. If, as TFS suggests, this material is "the one", then the rest will inevitably follow.

Re:Elevator will happen when materials are proven

[Anonymous Coward]

Oh look, some ludicrous sci-fi delusion. What's the matter, your box set of Star Trek: the Next Generation is useless as a guide to real engineering?
protip: stop reading so much sci-fi. Look out the window and notice how little the world has physically changed.
It's all about information. We are talking via internet, you didn't beam yourself here physically.

Understand? There are no magical materials. It's the Periodic Table of the Elements. That's all there is.

Re:Elevator will happen when materials are proven

[Anonymous Coward]

"That's the key to it. Period."

Appropriately, the Periodic Table of the Elements isn't just a good idea, it's the law.

Re:Elevator will happen when materials are proven

[dpidcoe]

The difference being that a tether snapping and raining superstrong microscopic diamond fibers 100's of km long in a path across the equator is several orders of magnitude more destructive than a bridge collapsing.

Re:Elevator will happen when materials are proven

[Anonymous Coward]

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 materials issue, and not one that carries any impossibilities, either.

Here are some quotes for you to contemplate:

"As far as sinking a ship with a bomb is concerned, you just can't do it."
-- Rear Admiral Clark Woodward, 1939

"The energy produced by the breaking down of the atom is a very poor kind of thing. Anyone who expects a source of power from the transformations of these atoms is talking moonshine."
-- Ernest Rutherford, 1930

"There is not the slightest indication that nuclear energy will be obtainable."
-- Albert Einstein, 1932

"Our inventions are wont to be pretty toys which distract our attention from serious things. We are in great haste to construct a magnetic telegraph from Maine to Texas; but Maine and Texas, it may be, have nothing important to communicate."
-- Henry David Thoreau

"I must confess that my imagination, in spite even of spurring, refuses to see any sort of submarine doing anything but suffocating its crew and foundering at sea."
-- H. G. Wells, 1901

"What can be more palpably absurd than the prospect held out of locomotives travelling twice the speed of stagecoaches?"
-- Quarterly Review, 1825

"Rail travel at high speed is not possible because passengers, unable to breathe, would die of asphyxia."
-- Dr. Dionysus Lardner, 1793-1859 ...you are a proud member of a very famous group of fools. :)

Re:Elevator will happen when materials are proven

[tehcyder]

The fact that A, B and C which were previously considered to be impossible eventually were made possible does not mean that D which is currently considered impossible will eventually be made possible.

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 passenger planes in service. It was never just about engineering a supersonic passenger plane.

Re:Elevator will happen when materials are proven

[ChrisMaple]

Wells had more than a failure of imagination, he had a failure of knowledge. In 1776, a submarine was used in the American Revolutionary War. https://en.wikipedia.org/wiki/Turtle_(submersible)

Re:Elevator will happen when materials are proven

[lucien86]

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..

Re:Elevator will happen when materials are proven

[david_thornley]

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're saying is that you can cherry-pick really stupid quotations from history. (You missed Admiral Leahy, in roughly the same position as the chairman of the JCS today) insisting in 1945 that a nuclear bomb was impossible, and pointing out he was an explosives expert.)

Re:Elevator will happen when materials are proven

[david_thornley]

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 and the conservation of momentum? Black holes have momentum, and it seems to me that some theoretician would have mentioned this in a peer-reviewed journal if it were true.

BTW, if you have special relativity and FTL, you've got time travel.

Re:Elevator will happen when materials are proven

[lucien86]

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 equally there is absolutely zero hard proof for the standard 4D space time version.. There are several pieces of indirect evidence for my FTL model, plus the FTL model unifies (a very slightly modified) general relativity with quantum mechanics and with classical physics, plus the FTL model is also at least an order of magnitude simpler than the standard relativistic model. The big negative for the FTL model is that its maths is non-continuous, and ‘ugly’, and has to map a number of infinite quantities. (I made the first step into the FTL while working on the maths of Strong AI on infinite non-finite sets and self-complete systems..)
I have recently found a real experiment that just might be able to test the two models against each other. - The FTL model predicts that black holes should have a central massive singularity, while general relativity predicts that a black holes mass should be distributed.. This difference is theoretically detectable in the behaviour of objects in close orbit around black holes.

As for negative mass matter, obviously again there is no proof on whether it exists or not. However if my model is correct then negative mass matter is a pretty good candidate for dark matter. The basic predicted behaviour of negative mass matter is that it is tachyonic (FTL coherent) and so it shouldn't interact with ordinary matter - except through gravity. In this model tachyons can also travel slower than light because their internal geometry remains FTL coherent at all STL speeds..

Re:Elevator will happen when materials are proven

[Anonymous Coward]

I wasn't attempting to be comprehensive. Just pointing out a very few of the many incorrect naysayers in history, for whatever reason(s), and indicating that the poster I was replying to had joined them, pontificating negative cluelessness about matters that have yet to be shown to comply with those assertions, and further, about matters that look quite doable to actual, you know, physicists.

Don't worry about it. If a space elevator is possible, it's going to happen, barring actual discovery of antigravity or some such equally unlikely technology. Our opinions will have no effect upon this whatsoever.

Lofstrom Loop still seems dicey

[OmniGeek]

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 would be staggering all by itself). From a practical standpoint, I cannot imagine any organization building either one of these on Earth; the costs and risk are too formidable.

For practical space launches, the best alternative would appear to be a hybrid air/space approach similar to Scaled Composites' SpaceShip One (also used by Orbital Sciences' Pegasus satellite launch system). Your first stage is essentially a cargo aircraft, which gets your space vehicle up past the first 10 KM of altitude and the first 600 KPH of velocity without the massive inefficiency of a first-stage rocket booster. The winged second stage is either a pure rocket vehicle or a hybrid air-breathing / rocket vehicle. This system uses atmospheric lift and rocket power where each is most effective; the big airfoils and air-breathing jet turbines stay in-atmosphere for immediate reuse (this is much more cost-effective in the long term than a reusable first-stage rocket booster, as it can be reused literally thousands of times between major overhauls).

IMO, this is what the future of space launch will look like.

Re:Lofstrom Loop still seems dicey

[dpidcoe]

Yep. Anything that can get the actual space part of the vehicle cheaply up past 10km and then let it go the rest of the way based on conventional means is the way to go.

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, the internal air pressure can be kept at that of the opening at the top. I have no idea what the upper theoretical limit of a linear motor is, but the chinese maglev hits somewhere close to 600km/h, so I would guess that 1200km/h in less than half the air density is reasonable (you could even let air in the back at the moment of launch to help push it hyperloop style).

Spaceelevators. How do they work?

[Anonymous Coward]

Can someone explain this to me?
It cannot be a simple elevator, because if you place vertical force outside of the spacecraft or make it affect the elevator (ex. by friction) you will be pulling the orbital elevator part down. Eventually collapsing the structure.
So maybe it is meant to be just a track for the spacecraft? So that the craft uses its own engine, but the elevator stabilizes the flight? Again, no. Because every destabilization creates a horizontal force that hits the track. And at this distance we can assume the material will act like a line - it will bend and then compensate this by... pulling the orbital part down. Same result.

So how does this magical thing is supposed to work?
(Apart from sucking tax money in and producing bribes.)

Re:Spaceelevators. How do they work?

[Anonymous Coward]

Or maybe the orbital part will have engines to compensate this pulling down effect?

But again the sum of fuel used by the craft and by the orbital thing will be constant.
Equal to the amount of fuel used by a simple rocket.

Plus imagine the cost of pumping the fuel up there.

Re:Spaceelevators. How do they work?

[Anonymous Coward]

Nope, it reaches *beyond* geostationary orbit, so that centrifugal force of Earth rotation (and the tip following) overcomes the centripetal force of gravity acting on the elevator, on the payload and on the counterweight beyond GEO. This way the rope is pulled taut and self-stabilizes into vertical position.

He was wrong. The other way round, though.

[Anonymous Coward]

About 0.1%. To push a ton into high orbit, you need 1000 tons of fuel.

A space elevator can be energy neutral, or even a positive generator, all you need for the latter is more mass coming in than going out.

Elevators going only one way would run out of platforms very quickly...

If I Had a Dime

[Anonymous Coward]

For every material I've seen touted. "This could be used to create a space elevator!"

How about fairy tears? Can those be used to create a space elevator? How about crocodile booties? No? Yes?

Space elevator for mars

[MobyDisk]

Would diamond/carbon nanofibers be sufficient for a mars or lunar space elevator?

Uh oh...

[Anonymous Coward]

The military applications are endless.

http://warhammer40k.wikia.com/wiki/Harlequin's_Kiss

Are there any designs for such an elevator...

[martinfb]

... yet conceptualized? Or how it could be built - given that materials become viable and available?

Oh great now I have to worry about shigawire.

[DrPeper]

Seriously. This will be the first published use of the material.