Slashdot Mirror
Space Elevator Company Fission
Dag Maggot writes "Highlift Systems seems to be going through some turbulent times with cofounder Michael Laine leaving to form his own space elevator company LiftPort. Interestingly, Liftport pledges to be a "transparent" company, and as such have provided the full text of the original space elevator proposal which was made to NASA NIAC." We mentioned Liftport before, but the proposal is new and quite interesting.
It's about time they started using fission for space elevators. They were much too slow when they were coal fired.
If I seem short sighted, it is because I stand on the shoulders of midgets
The space elevator seems to be the most promising alternative to the Shuttle program. The biggest problem are the carbon-nanotubes, it is not clear yet, how they are to be produced and a BIG quantity of them will be necessary for the project.
... or the poor connection of the server ... I hope for the first.
The site seems to be slashdotted already - 3 minutes, this should be a Slashdot record. On the other side it indicates the interest to the subject
I understand that basically that the space elevator is a an elevator which is moved up and down to an orbiting space station. The thing I'm trying to work out is how do you teather them together? Short of tying a rope to the backend of a rocket and firing it up I just can't work it out? Any ideas?
Rus
Cheap UK and US VPS
I've spoken with Mr Laine concerning Lift Port systems. From what he told me, he is not leaving High Lift. Lift port was simply created for some sort of capital creation reason.
So, as far as I know, Michael Laine has not left the Highlift...
Let's hope their space elevator can support more users then the web site.
Because, id like to see an alternative to storing nuclear waste underground (too much controversy and NIMN(not in my neighborhood)). We could safely lift the material up into space and then launch the waste somewhere else. This is still many years aways, but I hope they get some good funding to do their research, and build some test platforms.
later,
"Im drowning here, and you're describing the water!"
to the term "Elevator Music"
Imagine a few hours of that o_O
Damn, what civilization advances did I need for space elevator again? I'm gonna lose out on the space race!
---
"The chances of a demonic possession spreading are remote -- relax."
...please use the stairs!
Well, if their already going their own ways on this and they don't even know how to make this thing yet, I would call that a very promising begining! Who wants to do a Space Elevator startup?
Here are the google caches of the front page, and their FAQ:
Front Page
FAQ
Invest in this company NOW! It can only go up.
Im not here now... Im out KILLING pepperoni
I guess it is time to make a kind of "I survived slashdotting" signs for web-sites. Or T-shirts or something.
May Peace Prevail On Earth
I just had a rather strange thought about this:
Arthur C. Clarke would spinning in his grave right now, if he were dead.
If Mr. Edison had thought smarter he wouldn't sweat as much. --Nikola Tesla
Google's cache of liftport.com: http://216.239.57.100/search?q=cache:TiE-9Ofu6fUC: www.liftport.com/+&hl=en&ie=UTF-8
=If life was easy, i would be out of a job=
There are some crazy design specs that people don't usually consider besides the nanotubes and the lack thereof.
1) due to the weight of the cable, it needs to be thicker at the middle and taper off at the ends - this makes the attachment of a vehicle to traverse the cable considerably more difficult
2) the growing - you can't "lower" a cable from a space station. the center of gravity must remain at the geosync point if you want to stay afloat
3) the keeping cable tensioned - this involves capturing a sizable asteroid into an orbit dangerously close to the earth (as in, genocidal proportions if shit goes wrong) - and after you anchor the cable, push it back out so it will keep tension (geosync don't work here). A fly-by capture is out of the question, and actually dragging a asteroid to our doorsteps is impossible by today's figures.
Space elevator, while cool, has a loooong road ahead of it - I am not betting my money on it (within my lifetime, anyhow). Granted I probably seem like a pesky naysayer that's keeping technology from going places - but just imagine stuff we developed WITHOUT first thinking it through; I think the nuclear stockpile on US and Russian sides definitly proves my point.
I'm all for it if they can bring the damn asteroid here SAFELY, though. (Shuttles so far has a roughly 2% failure rate - and that's two completely fatal ones - I don't want the fate of the world depending on that kind of odds)
My life in the land of the rising sun.
... but they can't build a website that can handle slashdot ;)
I'll try later, eh?
Actually, the current model uses a turned crank powered by trained apes. Thanks to fission, the apes no longer have a job you jerk!
You can't judge a book by the way it wears its hair.
Yeah, but it isn't going to skyrocket...
If Mr. Edison had thought smarter he wouldn't sweat as much. --Nikola Tesla
Also, there won't be a great deal of taper if they get the material strength they expect - about a 2:1 ratio iirc.
Maybe you'd like to take a look at Liftport Authority Inc's flash site.
Nuclear power has come a long way since the first commercial reactors, and especially Chernobyl. Unfortunately I don't think the general public has been told.
Either way, Liftport has been talking about holding a competition at a Robotics convention (or summert, I forget) for making ribbon-climbing robots. In the rules of said competition, the entries get extra points for a remote, wireless power source for the climber.
This struck me as slightly odd, and likely unfeasable on the grand scale, but an interesting developmental path...
</humor>
*By the world wide space consortium?
This plan is clearly wrong. There is no mention of stealing underpants anywhere. How can you expect to make a profit without stealing underpants.
There is one small problem with space elevators. The cable has to carry it's own weight. If you were to use a steel wire of a few millimeters in diameter at the surface, the diameter at geostationary orbit would be about the diameter of the solar system. This is not including the counter weight.
This might seem like complete nonsens but that is from a theoretical physicist and writer, Dr Hans-Uno Bengtsson. The original reply from a "ask the expert column" in swedens biggest newspaper. Fungerar en rymdhiss?.
BTW: If the wire were to be made from kevlar it would only have to be a few hundred meters in diameter. With more exotic materials you could shrink it to less than a meter.
I wish people who believe in these conspiracies would do a bit of research first instead of going straight to alt.conspiracy. Come use some of the brain cells in your head. Ive posted a link to the jessica lynch in question. The domain name is for the person who won the Miss New York pagent. No relation to the rescued POW.
Miss New York City 2003
later,
"Im drowning here, and you're describing the water!"
"It is also a sick reminder to see how they could fathom using radioactive materials for power. As the decade wears on I imagine we will see plenty more of these last gasp efforts to legitimize outdated, unsafe, 20th Century technologies and mindsets."
I sure hope we'll see more... nuclear technology has advanced significantly since Chernobyl, and through research and application will advance further still in the coming years.
As for mindsets: yours is the only outdated one. Nuclear technology is a relatively recent development, and we have only seen the start of it so far. And you are already going to give up on it.
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
How about the manned lunar missions? those went passed the Van Allen belts.
What are the chances of building a space lift being allowed. People have trouble building tall buildings in some places due to the shadow, won't this cable have some issues like the fact that it would cast a shadow over the entire planet, also what if somthing goes wrong and the cable breaks, ever read the book series (red, gree, blue) mars where the cable came crashing down on mars? hmm i guess they could get around this by building it in a country thats willing (any country woth out fussy laws that want money).
Still it would be cool =)
cat
I found this link, not sure how accurate any of it is, provides a little explanation about the belts nature though. http://www.thekeyboard.org.uk/Van%20Allen%20belts
"They locked up a man who wanted to rule the world, the fools, they locked up the wrong man! L.Cohen
It's a very fine balance. On one hand, you could possibly pull this 'rock' from the air, crushing civilization below it (ouch), while too much centrifugal force could pull it from the dirt and send it catapulting through space. Hmmm. I think I'll seek residence _AWAY_ from these 'elevators'.
*sigh* Oh yeah, and have you examined the veracity of all the photo and video documentation of it? it is so full of holes. And I think if you look into the levels of ambient radiation out there, beginning at the van allen belt, you will find that it has been measured at higher rads than is safe for prolonged exposure to humans. And even if it was safish, as soon as the sun blasts a flare, fooom, there goes your humans. Where is there other evidence of life surviving out past the van allen belt apart from the highly promoted lunar missions? and why hasn't there been more lunar missions?
you can't keep peace with a gun
read my blog
I wish there was some there was some way that I could be outside playing basketball, in the rain, and not get wet.
regardless of the question of the safety of travelling beyond the earth, and ignoring the fact of the constant fluctuations of radiation emitted from the sun, it is one thing to stop circuitry from being fried by EMF, and another to stop a human from being terminally exposed to radiation
other than the apollo missions, there is no other empirical evidence (if you call the documentation on apollo empirical) of the safety of putting living things beyond the van allen belt. Why haven't any further efforts been made?
I think the answer is because they know it can't be done with present technology. Surely the russians would have had at least one stab at it if there was any truth to the apollo mission story.
you can't keep peace with a gun
read my blog
Hmmm... HTML content served as plain text. How irritating. However, due to Microsoft's violations of the HTTP specification, it will work with Internet Explorer, just not with anything else.
You may have noticed this term being spun about in the thread; the answer is nanotubes.
A nanotube is like a bucky-ball (buckminster fullerine) but elongated into a cylinder. To the uninitiated a bucky-ball is a small macromolecule composed of 60 carbons. It looks like a football (european) and hence its name. So nanotubes are cylinders of hexagonallybonded carbon.
Potentially you could have "threads" of nanotubes that are bonded completely with strong chemical bonds, in comparison most materials we use in construction today consist of mostly much weaker interactions based on small charge dipoles and momentary charge variation (van-der-vaals force). IIRC correctly a van-der-vaals bond is about a thousand times weaker than a covalent (chemical) bond, and it is forces like these that hold the materials like kevlar together. The way the carbons bond in nanotubes should be compared to that of diamond, so in layman's terms a nanotube is a very long and very narrow cylindrical diamond.
A rope or sheet of woven nanotubes (of good length) would have a surely unbelievable tensile strength and hence people want to use them in applications like these (as well as in many other areas).
However AFAIK nobody has managed to develop nanotubes efficiently with significant length yet. However I keep seeing journals with articles on nanotubes and their practical applications so money's going into this field and it can only be a matter of time before a method of cheap production is found. The only method I know to date is vaporisation of gaphite with a laser - the resulting dust contains a variety of carbon species including bucky balls and nanotubes.
Nanotubes also conduct electricity and heat efficiently and seem to act as excellent lubricant.
Just a minor question
Imagine holding a bucket of water, and then you spin around. The bucket of water will be drawn away from your body, extending your arms.
Wouldn't the same thing happen to the space elevator?
-smark
The revised, second-phase report, much advanced over the first, should appear Any Day Now. Just waiting for NASA approval. There's also a book that expands on the idea.
The web server was having troubles late last night, so slashdotting only provided the final straw. We'll be back.
"I want to build a space elevator to the moon!"
...
"No, I want to build a space elevator!"
"No, it's mine!"
"No way! I had the idea first!"
"No, I did!"
"MOM!!"
You're all a bunch of loonies.
+1 Insightful, -1 Troll. What can I say, I'm an Insightful Troll.
Yeah, I've examined the material very thoroughly. Holes? What holes? Every last one of those supposed "holes" has zillion times more reasonable explanation than the so-called "hole" itself.
Not that it has ever bothered you conspiracy theory loonies.
Yeah, it's NOT safe for prolonged exposure. Newsflash: moon is close, going there and back is a short trip, not prolonged exposure.
Yeah, if sun goes boom with people up there, you're a goner. Newsflash: most of those can be predicted, and as short a trip as going to moon and back can be planned between any major solar activity.
What comes to nobody going there again, well, nobody has wanted to pay for it. Why would anyone want to go there (excepting the race mentality)? It's pile of rock. It's not free you know, you can't just strap a rocket motor on an old tin can and have a vessel capable of reaching the Moon.
Russians specifically are not exactly known for their endless riches right now, nor the past few decades. Feel free to finance your own lunar mission if you've got billions to spare.
There is no evidence that it's safe up there. Quite contrary, everyone knows its not safe up there.
It was highlighted to me very strongly that we have not in truth as yet escaped the van allen belt in manned space travel. I don't know if anyone knows what I am talking about, but outside of the inner margin of the van allen belt it would take 6 inches of lead to make the radiation levels inside a spacecraft safe for a human.
9 .html
Bullshit. You've been listening to moan conspiracy theorists with only half a brain. Listen instead to somebody who knows what they're talking about. See: http://spider.ipac.caltech.edu/staff/waw/mad/mad1
I quote from the summary: "So the effect of such a dose, in the end, would not be enough to make the astronauts even noticeably ill."
Well, perhaps some fusion of the two designs is in order.. Whilst I wouldn't reccomend building a "Tower to the Sky" (Hey, it worked in Babel, didn't it? Didn't it?), an elevator lobby of Petronaus x2 wouldn't be such a bad idea, and if you aren't going to supply office space (and mosque space, &etc) then building a relatively strong structure that could be used as a pre-launch staging area wouldn't be such a bad idea. Cargo and support could be held way up high and served by more conventional elevators at lower cost and higher feasibility.
If you build thinking in the same vein as the Eiffel Tower, in which the structure itself actually weighs less than the atmosphere around it and is actually supported by that atmosphere, then you could get quite a ways up. Of course, you also have to consider, the higher up you go, the more vulnerable your structure becomes, the more prone to damage it is, and the more difficult it is to build. Also, it takes a very tall building before gravity begins to be negated by altitude.
So maybe the tower idea isn't such a great idea anyway. Yet. Perhaps we should take things one step at a time.. Elevator now, since it is more feasible (cough) and building into the sky later when we can work around silly physics. I don't care how we do it, so long as we make a nice, big footprint in space. Quickly.
listening to moan conspiracy theorists
Ooops. That's moon, of course...
>Chernobyl Nuclear Power Station accident, 1986 = 810 curies released
>(above figures from www.space4peace.com)
> I believe the next series Martian probe launches are all slated to carry fissionable materials. So we are looking at potentially poisoning the entire population of central Florida as opposed to just a couple of places like Chernobyl and Kiev. That is an order of magnitude higher. A significant improvement.
And how many curies from atmospheric nuclear testing in the 50s?
Answer: several billion which has now decayed to around 400K.
And how much was Pu-239? About 225,000, from the first link.
We've already had your famed civilization-ending release of nasties into the environment. We did it deliberately (We didn't know any better. D'oh!). And yet, we're still here.
We've learned how to make RTGs safe for re-entry so the incident of 1964 doesn't happen again. But more to the point, nuclear power is the only technology with a high enough power density to allow us to extract fuel from the Martian environment for a "Mars Direct" plan.
If you wanna see men (or even long-term surface probes/rovers) on Mars for more than a couple of weeks, it's the only way to go. You can engineer your way around the risks of RTGs. You can't engineer your way out of using 'em.
I think this is a case of a chain being as strong as its weakest link. You can build structures like this, but I don't believe any such structure can give a higher tensile strength/mass unit than just a cable made from the same material could. All you do is spread the material around a bit.
from earth to orbit faster than you can see the next post on slashdot about the space elevator.
That's why they're building this space elevator thingy, see. They send the first strand up in one or two shuttles. Part of the shuttle payload is enough extra fuel to get to GEO. They unroll the strand. They send lightweight climbers up with the next strand. Now they have two strands, the climbers can carry twice as much, and iterate until you have a satisfactory number of strands emplaced.
No habitats, and the ribbon weighs startlingly little per km (something like 7.5kg, OTToMH).
Got time? Spend some of it coding or testing
Maybe I'm missing the point, but why does anybody give this article any credibility whatsoever? If you look at the slashdot article, they act like this is a legitimate company with a realistic goal. But what kind of company puts animated GIFs of a "space elevator" on their home page and supports their idea with citations from science fiction novels? They tell us this has been considered by NASA. But so has the Podkletnov effect, which supposedly miraculously shields objects from earth's gravity. Either NASA isn't given enough funding to do background checks, or they're checking out every crackpot who comes along in hopes of finding gold. I'm betting this is a hoax, but if it isn't, this guy has about as much chance of constructing his space elevator as Imari Stevenson has of designing a Final Fantasy sequel. A word to the wise.
Think of it as a static strap for an entire planet. They've designed it with electric potentials in mind, too.
HighLiftSystems/LiftPort have already thought of a heck of a lot of stuff, the odds of something truly unique arising here is basically zero. However, if it does, they'll know because they're reading this.
Having your site flattened by SlashDot is something you tend to notice.
Got time? Spend some of it coding or testing
I'm pleased somebody found the post funny, but I was attempting to seriously raise a point that I'm quite curious about.
The original question was a bit mixed up. Building up and building down deserve to be treated seperately as the issue is already a source of much confusion.
Building down from orbit does seem like a cool way to go except for the obvious problem of transporting the materials. But assumuming that you were willing to commit the resources, it seems like you could easily increase the tensile stength of any material by adding flexible buffers, the simplest example being spring loaded joints. Using the analogy of a chain, if every link was spring loaded, you would be adding enormous mechanical strength to the chain. Of course you'de adding weight and complexity as well, but a spring loaded chain is quite a simplified version of something that might be practical in this application.
The point that keeps running through my mind is that you must be able to add tensile strength by design where it doesn't exist otherwise. Perhaps I'm wrong, but it seems there are many real world examples where this is true.
But let's skip the building down side for the moment and turn back to the tower of Babel part which is where the real fun is. Instead of asking is this possible, let me rephrase the question thuswise: What's the best possible metal tower design strengthwise.
Is it a simple octet strut or is it more complex?
If you arranged the final shape as a constant-diameter tube surrounded by a variable-thickness wall, that would be quite a bright idea.
The only fly in the ointment I can think of WRT that configuration against the current plans is that they plan to power the climbers with a laser from the ground. To do that down the guts of a tube would require an absolutely straight tube, and she ain't gunna happen. But there are other ways of powering a climber.
Got time? Spend some of it coding or testing
even your minimal working model is 40 thousand miles long and costs a Dr Evil sum. :)
You mean "one mieeelion dollars?"
...and yes, we will work in your browser and be navigable by blind users and probably even make validator.w3.org happy. These are all definite design goals for the new website. Small technical details are important to these people.
Got time? Spend some of it coding or testing
...and push him out just after you get above the last cloud. No repeat offenders. Plenty of time to think about what he's just done.
BTW, at (say) 15m per floor, you'd have to fit about six or seven million buttons into the elevator design.
Got time? Spend some of it coding or testing
Simple? They're not competitors, they have different purposes, so different structures.
Got time? Spend some of it coding or testing
Bungeeeeeeeeeee...!
Got time? Spend some of it coding or testing
Not much of a counterweight is needed (certainly no asteroid), and who would brake? Why waste precious momentum? Just time your ascent so you slingshot off the end of the cable aimed the right way (a `tramline' orbit), and you're in business.
Got time? Spend some of it coding or testing
No, less than a twentieth of a trillion. Read their FAQ before posting here.
No, not very much will happen. If they blew off ten km of elevator, the remaining 99.99% of it would still be orbiting stably. Read their FAQ before posting here.
Took a while to happen to the WTC, and this time they'd be ready for it, and anyone with half a hemisphere left in their heads would put a whacking great no-fly zone around it, and it's being built in a remote (from 'planes) location, and could mount its own antiaircraft defenses anyway, and... RTFFAQP, dammit!
Many of which have been answered by people with a great deal of technical skill. RTFFAQP.
Got time? Spend some of it coding or testing
Slashdot needs to make a space elevator thread... people keep talking more and more about it and it's becoming more and more possible to build...
- Danny
How on earth do you get money to just talk about the cool ways someone could build a space elevator? This is not intended to be a troll or anything, I'm actually curious how this works.
I would understand if they were just some guys using their spare time to develop specs and a plan, but this guy formed a company to develop this idea and had it funded somehow. I don't see how they plan to make money, or how they were able to pass this off as a legitimate business. They're not building the elevator, so there's no chance of future revenue from that, they're not selling anything, they're just "investigating". How do you get money to spin your wheels and not produce anything? (Hold the dot com jokes)
Unfortunately, yes, it is out of the question. It has been mentioned elsewhere (in the article as well, I believe) that the necessary taper of a steel cable that would hold the weight of a 100,000 km cable, at the middle the diameter of the cable would be roughly the diameter of the solar system. By spreading the material out more, you increase that size further. Not to mention, the tallest structure you can build on Earth (without some type of countersink to take some of the force off) is about 42 miles. So such a structure you would have to build down from orbit.
The advantage of a carbon nanotube structure is a weight savings, some 7 times, coupled by an increase in tensile strength by 60 times, according to some theoretical estimates.
When in doubt, f*ck it. When not in doubt, get in doubt!
Hey, I like the "ban nuclear power" people... It's fun asking them if they'd like to turn off the sun.
:)
I'm waiting for a response of "Okay, nuclear power is fine, if it's 150 million kilometers away!"
Eventually, I'll run into a eco-freak with a sense of humor like mine. Then I'll be really worried.
And yes, the sun is *so* 20th Century.
This is my sig. There are many like it but this one is... Oops. Frank, I've got your sig again! Where's mine?
I've been following HighLift for months now and I am very clear about the idea of the nanotube and I think it's great. And I totally understand and have read that a steel CABLE will not work.
But if you read what I wrote, you might notice I very specifically indicate that this would not be a CABLE. It's not that I didn't read up on this stuff. This is a novel idea as far as Slashdot posts on space elevators and because I've read every post in the archives which is obviously not true for even a tiny minority of the people posting today.
Oh well, whatever. No big deal. This story didn't get a tenth of the posts the earlier ones did. I thought I was going to be addressing people who knew better as earlier HighLift stories brought out tons of Physics PhDs. I guess they're all watching the news.
Assuming all the uninvented stuff gets invented, the proposal as-is has no solution for lightning, and admits that the first lightning strike may well destroy the cable. Increasing the cable's resistance may simply not work because of ... rain, coating the cable. The 'solution' is to park the cable at the place on the equator that has the least lightning, but it's acknowledged that just one lightning strike would probably spell the end of everything.
The point that keeps running through my mind is that you must be able to add tensile strength by design where it doesn't exist otherwise. Perhaps I'm wrong, but it seems there are many real world examples where this is true.
You're wrong.
Fundamentally, you cannot "add" tensile strength to a material through geometry. You can create a structure that spreads load out, but you cannot make the components of that structure capable of bearing more weight.
Think of a single steel I-beam in your tower. Sitting verticaly, there is only so much weight that you can put on top of the I-beam. Nothing can change that, as it is a fundamental property of the material. All you can do is distribute the weight among other I-beams, so each beam has to hold up less. This is true for each horizontal cross-section of the tower. A good geometry provides even load distribution while minimizing the amount of material used (to reduce the weight lower sections have to support).
BTW, notice that an I-beam itself is such a geometry. The shape resists bending and twisting, but with less material than a solid rectangular beam.
I have no idea what the ideal geometry is, as I'm not a civil engineer. But I do know that no geometry can make steel stronger than steel, and thus eventually you're going to have to start making your base wider to support the weight above it, and to get to 60,000 km you'll have to have a ridiculously wide base (assuming that you could create a geometry that spread the load out over the entire base).
Same thing with hanging, only more obvious.
The enemies of Democracy are
A project like this simply cannot succeed until the threat of terrorism against it is miniscule. No-one would put any real money into this with any chance of a terrorist action occurring against it.
I haven't seen anything about the effect this would have on the Earths rotation. To continue with their analogy of a ball on a string, the weight moving OUT in the string slows the speed of rotation. Conversely, as a weight is brought closer to the Earth it would increase the speed of rotation. AND, if onle 1 elevator went up wouldn't it change the balance of the rotation?
They are frequently asked...
Cable width?
airplanes?
orbitology?
how they plan to lower the cable?
how they plan to connect the cable?
how payloads can actually be lifted and forces dealt with?
initial chemical-launches required?
first ribbon payloads?
space debris?
weather?
space weather?
electrical potentials?
what if the cable breaks?
environmental concerns?
safety?
how to power the lift?
etc. etc. etc.
none of these are unique questions.... they fall under "frequently asked".
Read the answers to your frequently asked questions, and they will be answered.
if you have a UNIQUE question - that should get rated a +5... but so far, no one has one of those that i've seen.
Geezuz tapdancing Krist.
(folds up soapbox, puts away megaphone)
guns kill people like spoons make Rosie O'Donnell fat.
After reading the article completely and carefully my feeling is that it is feasible accept for one small thing. They cannot provide sufficent proof that the cable can be built with accessible technology. The first step in the project should be the creation of a 50 meter cable with the properties that they say are required. If this is possible everything else is trivial (although a lot of work will still be required!) Plus it allows the testing of all other aspects of the project. I think that this would be a wonderful (and cheap) pilot project. Throw a couple hundred million at building the cable prototype. It sounds like a really good gamble. If that works everything else will just fall into place.
They also subscribe to the intuitively linear view of progress, rather than the (double) exponential rate.
--
Power to the Peaceful
I don't have a PhD in Physics, though my advisor at Brown has a Nobel in it. I switched to computers junior year.
Turning the ribbon into a pipe is one thing, turning it into a whacking great optical fibre is much more difficult. For one thing, your optical fibre is very slim and doesn't need to do tens of thousands of km in one run. For another, it's not carrying megawatts.
That doesn't stop the idea from being terribly attractive, though. (-:
Got time? Spend some of it coding or testing
Missing ingredient: you're not taking the whole ribbon up in that launch, you're taking up a single strand.
Good point. I suspect that since the ribbon is an excellent conductor and at least as good a radiator as it is an acceptor, the technique will be to operate it more-or-less side-on to the sunlight.
Also true, but the improvements now remaining to be made are incremental rather than revolutionary. In short, we can't do it yet, but we know that there are ways to do it. And if we sit on our collective backsides until absolutely everything we need in in place before starting to set up, that might add another decade of waiting before we can retire most of our rockets.
Got time? Spend some of it coding or testing
Is windloading taken into account at all? I could understand if the entire thread was the thickness of a piece of paper in all dimensions, but if it's three feet wide the windloading would be HUGE! skyscraper architects already have huge problems with this, and they're not attempting anything in the order of 40,000 km (though I realize there isn't an atmosphere for a lot of that). How could they possibly hope to compensate for windloading without having an immense, impractical mass at the orbital end?
Eh? If you make the ribbon skinnier, you make the heat uptake less as well. No worries. Self-solving problem.
As I understand it, the ribbon tapers as well. So the section near GEO would be a good deal heavier than the rest, but most of the ribbon would not. I think 7.5g/m is the average weight of the completed ribbon, not one strand. In terms of raw strength, it beats the crap out of fishing line (by at least two or three orders of magnitude).
Your concerns about how far we've got with nanotubes are valid. If we only do a tenth as well as we think we can, it would completely bugger LiftPort's economics but the elevator could still be conomically constructed. In fact, lopping the lift costs by a couple of orders of magnitude means that the second powersat you lofted using it would have paid for the entire project. If construction costs went up tenfold, it would take twenty powersats but would still pay for itself based on that revenue alone.
I imagine that quite a number of scientists would be overjoyed to have essentially permanent access to areas like the stratosphere (no more sounding rockets), and that providing same would be an immensely profitable sideline to actually orbiting stuff.
In practice, one of the first loads to orbit would be the start of the next ribbon. Can't have too much of a good thing. I imagine that a burgeoning mini metropolis like Broome or Port Hedland (both have small international airports) would be delighted to play home base to a ribbon of their own.
Got time? Spend some of it coding or testing
Metal lattice is probably out of the question, as is any other "tower of babel" for structural reasons, but I can imagine that part of the answer maybe in using a tower for the first few miles. If we build a huge tower on top of the mount Everest that will already help us along for the first 15 miles or so with conventional technology, and this may help reduce a lot of the problems with the cable. Air is thinner so less wind, less cable needed (the last part is always the most expensive part), etc. Then again, building on top of mount Everest may be just as hard as building a space elevator.
This sig is just as redundant as the rest of this posting
I have enough trouble (and fun) stone cold sober, I don't need to pour drain cleaner into my system to make things weird.
I don't know about you, but your grammar is certainly on drugs...
Interpolating the first part of your missif, you're saying that the end of the cable is whipping around at 10km/s. More or less - it's actually about 7 1/2km/s, and...?
This is not a rocket, this is a monorail running on a very thin rail. 100,000km to end of cable, Enter, 120km/hr, Enter, DIV -> 833 hours, 24, DIV -> 35 days. Time to GEO (roughly 36,000km) is roughly 12.5 days. At 120 km/h relative to the ribbon.
As to the rest of your figures... at 3km/h, it would take you over 33,000 hours (1390 days - or 3 years, 9 1/2 months) to transit the cable... or, alternately, you need to do over 8300km/h (2.3km/s) to transit the cable in 12 hours - at which point, yes, braking does become an issue. (-:
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You obviously have no clue what a solar flare is and does. One thing they produce very little of (almost the only thing) is light.
The jury's still out on that one, but it seems that even single-walled nanotubes would be pretty much immune when isolated from O2 (such as by the resin matrix LiftPort are planning to embed the fibres in as a part of joining individual strands). Really, all we can do is wait until the experiments have been done.
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Oh, that's right, I forgot. We're on SlashDot... (-:
Got time? Spend some of it coding or testing
My first thought was: `and you posted this to SlashDot?' (-:
From what I know, he was in a hurry to get the book into print and had/has very little money with which to do it. One purpose of the book is to provide a wage or two to help keep the company afloat until serious investors happen. I guess the next edition will be better proofed.
Got time? Spend some of it coding or testing
Yes, ffor the humour-impaired, that was indeed a pun.
Got time? Spend some of it coding or testing
Picture of a server crushed underneath a /. logo?
Picture of a rack with a huge bulge in the data cable rushing toward it?
Picture of a thousand geeks all jumping on a single 1RU box at once?
Got time? Spend some of it coding or testing
One thing I haven't found reference to is the fact that carbon nanotubes absorb light quickly but can't radiate the heat and thus tend to explode under intense light. Even if you paint the ribbon with high reflective index white paint, a micrometeor hit under full sunlight would have devastating effects. Perhaps the lack of oxygen would prevent an actual detonation, but under the intense and unfiltered light of the sun, wouldn't they at least melt very rapidly? You could end up with destabilizing hole in the ribbon.
Anyone given any thought to this?
*** *** You're just jealous 'cause the voices talk to me... ***
Ooops. That's moon, of course.
Heh, I read it as a typo of "moaning conspiracy theorists", which is just as accurate, IMO.
Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana
Even ignoring environmental effects (e.g., wind), steel is not strong enough to use it to build a tower into space, even using an Eiffel-type arrangement (large base, tapering to a small top).
No material (yet known) is.
The bottom just could not support the weight of everything above it.
Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana
Thank ya kindly.
Ya got to get some mud on your boots to get some clams, thanks for the clam.
In the process of searching for Geoffery Landis' thoughts on the matter I came across some interesting stuff in Google news regarding active mechanical supports to a structure. This was precisely my point. The suggestion that the strength of a material cannot be mechanically enhanced flies in the face of dozens if not thousands of real world examples. Thanks again Bob. You helped narrow things down with that tip. Next time the topic comes up, I'll be ready with some links, facts and figures.
Or perchance, it's your attention span that's on drugs? Grammar Nazi away my grammar, there was absolutely nothing wrong with it. And while at it, read what I posted more carefully. I said:
[...] speed at the end of the cable could be about 10 km per sec [...]
Speed at the end. Speed of the payload at the end of the cable. Not "speed of the end of the cable." Distance 120,000 km. Average speed estimated at conservative 3 kph. 120,000 divided by 3 equals 40,000 seconds total travelling time. That's just over 11 hours.
As for your claim that it's not a rocket, well, that's debatable. Who says it's a vertical monorail train? There have been several propulsion methods proposed. I got my info here. Not the most scientific of sources, but at least my claim holds a source, unlike your ramblings. (Jeez, 120kph as top speed....any modern rapid rail transit system beats that, and they have stuff like air drag to factor in. Did you pull that number out of thin air, pardon the pun?)
(-:
The 120kph came from (IIRC) a discussion with HighLiftSystems some time ago. I think the're being conservative for a number of reasons, including that the device flexes.
Got time? Spend some of it coding or testing