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The Space Elevator - Public or Private?
AtomicGoat writes "The Space Review reports that a Space Elevator may not get built without help from the U.S. Government, but the notion that 'the DoD can also provide a sense of fiscal discipline when dealing with large, expensive programs' sounds like an Onion story. Right now a small private company (Liftport), not NASA or the Air Force, is in the lead on revolutionary space travel."
Not public or private. I like my variables protected.
I wonder if I can go all the way up just to sight see. Love to be a tourist :)
NO! NO! Please don't mod me, I'm too young to die a troll. *click* Oh the pain, the pain...
Of course it needs government support; you can't just put up an X-mile high tower without worrying about security, shared land use, population relocation, etc. These are all things that government does. Without some government muscle, a private space elevator company would be sunk.
but they do have a store. I want my liftport lunchbox! (http://www.cafepress.com/liftport.13005720)
That's a little over twice around the planet, people. Anyone who considers disaster scenarios should think about that. If something goes wrong, there's a possibility that the elevator cable would wrap itself around Earth, hard. Countries under the cable's path probably wouldn't like that. Their governments would make a great deal of noise, just considering the possibility.
Given that the governments are involved to that extent anyway, it's natural to assume that they will also want to oversee construction and whatnot, just to make sure Things Are Done Right. Now, do you want a government with no stake in the elevator watchdogging the process, or one that does have a serious financial stake?
In the same way that soon after the first aeroplane flights had been made, hundreds were being made: Given the high number of competitors and what we have seen so far, I think it likely that someone's going to win the Ansari X prize. Space flight's going to become cheap, and it won't take long for someone private to get a space evelator line up.
Well, people may like to make jokes about $800 hammers,
but the DoD folks are utter geniuses of financial management when compared withother federal agencies such as the FAA
or NASA.
But deployment...that's another story.
Regardless of who is 'in the lead', the US government will likely be heavily involved if not directly controlling a space elevator. Cheap transportation into space is far too lucrative, not to mention useful, to ignore.
We, the people of Mars, reclaim this building for us!
We are tired of the metanacs controlling our lives!
We must control the entrance into our world!
Give us back what is rightfully ours!
(Red/Green/Blue Mars are cool)
Someday perhaps, but DOD, cost effective? Please... Giving something this to the government would probably ruin any efficiency in it, and a private company financing this...could happen, but most likely not for some time.
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Queue, the correction hordes...
The grass is only greener, if you don't take care of your own lawn.
Why are we wasting government money on an elevator that will take people into outerspace? Is there really a purpose to this thing or is it just a black hole that we're throwing money into? Seems like a waste of time and resources.
But the platform would be built on international waters, and the elevator will reach into space, which no government owns. I don't see why any government should have to get get involved, if the LiftPort Group can get this off the ground without any government help, all the more power to them!
Sig? No thanks, I'm trying to quit.
Private: the elevator attendant (a Valued Associate) is your Customer Interface to the Space Elevator. The individual is in his/her teens, wears plenty of Company Issued "Flair," and beams incessantly as you say at what altitude you want your spacecraft released.
Public: the elevator attendant (a Civil Servant) only grudgingly speaks to you. The individual, dressed in a simple brown uniform, is in upper middle age, and won't release your spacecraft from the elevator without a 29B/6 form that's been stamped.
*ding ding*
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Please watch your step as you exit and Thank You very much for shopping at Wal-Mart.
Friends help you move...
REAL Friends help you move dead bodies... ^_^
Well, if a private company can't do it without support of the government, then it was not meant to be. Let's just go with libertarianism and keep the government out of everything. Allowing the government to fune even 1 penny would go against the 10th amenment in the constitution.
a Space Elevator may not get built without help from the U.S. Government
...
In other news, physicists report that a space elevator may not get built without help from the universe itself
topreacher@signature.slashdot.org 1% rm -rf sig
A space elevator would not so much be "put up" as "lowered down". The energy and materials requirements for lowering a cable from orbit are drastically different from building a tower to the stars.
When you lower a cable, it is relatively easy to anchor it to a floating platform in the middle of the ocean. Therefore, there is no worry about equatorial real estate, local population, eminent domain, or other government-dominated nonsense.
"This quote is a product of the Frobozz Magic Quote Company."
Great to see space elevator research is starting to pick up. I think its safe to say now that its the only cheap way to space. Governments will have to be involved, as will many companies. Wherever the anchor is will be a huge decision that could completely turn around a 3rd world nation -- or political instability could make it impossible. There's not many "safe" equitorial sites with lots of room for support organization -- look at a map.
The safety issue could really kill it though. If it starts to wrap around the earth, watch out. There has to be a way to "cut the cord" at this and and hope it flies out into space. Of course, a release mechanism like that is a liability in and of itself. So that's a very tough, maybe the toughest, hurdle.
Moo.
A company with a store like theirs doesn't sound much like the kind of company to pull of a feat of this magnitude. This seems more like a ploy to get as much money out of some science hype as they can before people realize that there is no chance that anything will ever be made aside from a lunchbox.
Not that the goverment couldnt reuse it...they like things complicated like that.
Support more choices in goverment-Vote 3rd party.
While a project as risky and expensive as a space elevator would seem to be solely in the realm of government, private investors could play a role. Already one company, LiftPort, is trying to commercially develop a space elevator.
*TRYING*
For a commercial startup to get the mass amounts of funding needed for a venture like this seems VERY unlikely to me. With the current cynicism surrounding space exploration as well as the exorbitant costs associated here, I just don't see it happening. But maybe I'm just a pessimist.
... is like "military intelligence" or "jumbo shrimp".
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
...so public space travel == communism?
Sig? No thanks, I'm trying to quit.
The "elevator" falling down is less dangerous than a sheet of newspaper falling down. It's that thin. It's not going to hurt anyone. They said it will likely break up and shred into small pieces as it falls. If it breaks anywhere within the atmosphere (due to weather, terrorism, plane crash, etc) only a few miles fall down and they simply lower some more down and reattach it. The few miles you lose in the atmosphere is a pittance.
It will be in international waters, off of South America (I want to say Peru?). So the buyoff of any government for land, airspace, etc is not required.
There are a LOT of hurdles left. Not only can the nanotube fibers not be made in sufficient length and quantity, but they have not even looked at what happens to a model of a few-meter wide ribbon in the atmosphere. We also don't have a lift vehicle capable of getting the big spool and counterweight they need up just past geosync orbit.
Real programmers use "copy con program.exe"
Not necessarily. Build it on a privately-owned island or some such. No regulations, no permits required, etc. I'd imagine that something like this would best be built along the equator anyways, for technical reasons. I don't know for certain, but I'd imagine that the tilt of the earth could cause problems. Maybe a floating platform, or in an equatorial country that would provide uber-security in exchange for the obvious economic benefits.
(tig)
Ignorance and prejudice and fear
Walk hand in hand
One of the companies that has been referred to in discussions of the X-Prize is going to use an inflatable balloon system. Ultimately, they plan on having a LEO space station supported by helium-filled balloons. (Insert usual joke about helium balloons. Insert usual technical rebuttal showing how It's Not As Silly As It Sounds).
If this system has potential, why not use this as the initial lift phase of a space elevator? Unspool out the first piece of carbon nanotube cable and leave the initial lift balloon tethered to its end. Hoist another spool, and splice it onto the end; inflate another balloon and send it up farther. Keep adding lengths until you reach the LEO altitude of your inflatable space station, then send it up along the tether. You'll end up with a string, supported at multiple points by small balloon and on it's end by a really big balloon.
That space station would help to support the weight of the tether, and could either serve as a launching point for the cable which would go out to GEO, or as a device to catch a cable lowered down from GEO.
The inflatable space station people claim tremendous efficiencies in lift because of the passive nature of the lifting force of balloons (negative buoyancy) vs. rockets (thrust). Why not use this approach to leverage the space elevator cable?
By the way, I'm thinking that all of this, once complete, would merely serve as the scaffold to support the climbers, splicers, etc., with which the final Space Elevator cables would be built, connecting ground to GEO.
The man who does not read good books has no advantage over the man who cannot read them. - Mark Twain
Elevator music all the way into space???
Seriously though, I think this is a crazy (as in dumb) idea. I'll give one example: Terrorists.
So, this means that everything that goes into building it will have to get up there first. This means that the huge amount of material needed will give a tremenduous incentive to mine the moon, or even perhaps the asteroïd belt.
Whatever the way you choose to dice it or slice it, it means that you'll definitely need cheap space access just to get the machinery and the workers there, if not the materials.
And can it really be that cheaper? After all, the Chunnel didn't kill the ferry business accross the channel... Likewise, despite the significant cost savings a space elevator will entail, we will have to pay for the darn thing. So, you can expect marginal (less than an order of magnitude) savings over the cheapest rocket method...Don't build it in the states then.
"I'd imagine that something like this would best be built along the equator anyways, for technical reasons." IIRC this _must_ be built at the equator, specifically because of the requirements for a corrosponding point in space at a geo orbit. -nB
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Alan Jackson: Where were you when they built the ladder to heaven?
Did it make you feel like cryin', or did you think it was kind of gay?
Well I, for one, believe in the ladder to heaven. Oh yeah yeah yeah. 9-11
[the townsfolk begin to cry]
I said 9-11, 9-11, 9-11, Ni-hi, hi-hine___
Where were you when they ran out of stuff to build the ladder to heaven?
Where were you when they saved that ladder to heaven?
Where were you when they decided heaven was a more intangible idea 'n you couldn't, you couldn't really get there?
[walks up to the boys] You little bastards ruined my latest song! [drives his guitar into the snow, breaking it, then walks away]
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Those are _VERY_ dangerous words historically.
I don't see that Nasa has "helped" space development much-especially the last 25 years. I can easily believe the world would be _further_ into space development without the various destructive government policies the last few decades that have turned the United States from an industrial powerhouse into a major debtor nation.
What the DoD ought to be more worried about is making the US into a technologically effective nation again(the US has a trade deficit even in high tech goods now).
Now, whoever creates a space elevator is going to instantly become a major, global power--and the DoD has reason to be concerned about such issues--but there are a lot of other pressing issues the DoD is also ignoring(i.e. the US borders just aren't very secure).
Unless the US government seriously gets its act together, I doubt very much it will have much of a constructive role in space development-this isnt' the government of Franklin and Jefferson any more-and is more like what they warned us against.
Even if it is lowered down from a stationary platform from space...I wanna have my U.S. Air Force standing by to blow the thing to smithereens if it wanders off course! You also say "relatively easy to anchor it to a floating platform in the middle of the ocean" There are a lot of assumptions here, one of which is that they would not want to build on a continental shelf (which will probably be controlled by a nearby country). Another is that lowering down is a nice, stable process. If it really were so...the Earth-bound tether point would be trivial. In any case, "easy" is not assured.
Just like Tom from Office Space, the people at liftport tell their friends about their idea.
Tom Smykowski : It's a "Jump to Conclusions Mat". You see, you have this mat, with different CONCLUSIONS written on it that you could JUMP TO.
Michael Bolton : That is the worst idea I've ever heard.
Samir : Yes, this is horrible, this idea.
and they go ahead with it anyway. they couldn't come up with a more efficient way to get around in space? say like this?
This
According to the http://www.liftport.com/faq.php#science2b FAQ the cable will break if it gets struck by lightening or hit by a Category 5 hurricane. Basically their argument seems to be that this won't be a problem because they'll build it where there isn't any lightening or hurricanes. That sounds kind of risky to me considering the massive amount of money involved. I mean huricanes I can see but isn't there lightening everwhere?
"... drowning in information,
security
Private companies don't need governments to take care of their security for them. A space elevator will not be a very tempting target to attack externally. You can only hit the very, very, very bottom, and if you break it, you just lower a replacement for the bottom 0.01% that broke off. The main threat is crazy people somehow sneaking bombs aboard, and governments have proven that they can be just as gloriously incompetent at security screening as anybody else.
shared land use
And if the private company puts it in the middle of the ocean, or on an island that they own?
population relocation
And if there's no population to relocate, like in one of the scenarios above?
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
If the DoD wanted to do something constructive:
they could sponsor some prize awards for some basic pilot projects here.
I've seen some folks claim that there is the potential to make a Roton or something similar work on the level of capital private corporations have-it just may be happen in the US government gets out of the way-or is distracted by other things.
Government When you call to find out why you got released at 50 miles altitude rather than geosync from the Halliburton(tm) Space Elevator, your call has a bunch of mysterious clicks in the background before being cut off entirely. After you die horribly in the crash, it's announced that you were a terrorist who crashed the elevator deliberatly. The president goes on to bomb Syria, even though you'd never even been there.
"Seven Deadly Sins? I thought it was a to-do list!"
Bah those monks are pansies.
Just throw some butterflies at them and they run off screaming.
Going up ?
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Aint that how that free enterprise thing works?
Aint America great!?
eat shiat and bark at the moon
Yes, but you still need to worry about somebody flying a plane into it, either intentionally or accidentally. This is something that aircraft carriers are good for. Last time I checked, not that many private companies owned their own aircraft carrier...
"Freedom means freedom for everybody" -- Dick Cheney
It looks like what I knew -- or thought I knew -- about space elevators is a bit dated. Which amounts to "wildly inaccurate" now. For those of you who might want to see some direct comparisons between the current technology and what was believed a few years ago, see LiftPort's Frequent Misconceptions page. It was enlightening, at least to me.
Private Space Elevator: Musak plays in the background.
Public Space Elevator: John Ashcroft singing "When the Eagle Soars" plays in the background.
I hear this all the time. It's simply not true. The FAQ you reference has an important qualifier: "The majority, the long end out in space, gains enough speed that it burns up in the atmosphere, with the lower portion falling into the sea"
That means that in order to be harmless, it'd have to be built out in the middle of the sea. They're actually seriously suggesting they use a ship/platform as the base.
The fact remains that there are numerous, numerous nearly impossible technical challenges. For example- "Objects larger than about 10 cm have a finite possibility of destroying the ribbon". Nobody has the capability to track objects that small. They are "seeking" radar that can track objects that small- ie, they haven't found one yet.
Further:
One of the nice things about our anchor site is that it is in the middle of nowhere, approximately 650 km from shipping or plane routes.
If it's so goddamn far from everything else, it's not going to make for a very efficient means of getting stuff from "civilization" to space, now is it?
I'm so sick of hearing about space elevators. It's a technology dreamt up by science fiction writers who do not have to deal with reality beyond a level the reader expects, and Space Fetishists have become obsessed by the concept, despite numerous obvious problems. They dismiss such problems with a wave of the hand, with solutions qualified with "eventually", "we can", "we might be able to", and "we think". They're entirely serious when they say, "Oh, we won't have to worry about the part that doesn't fly off into orbit, because we'll put it in the middle of the ocean." Right. That doesn't create its own problems, no, not at all.
When will you people get it through your heads that space elevators won't work?
Please help metamoderate.
I suspect that if it requires an air force to protect it, that the government should be involved. The land (privately-owned island) isn't the part that's in danger.
http://www.gizmonicsinc.com/elevator/
http://w
I would love to see something truly this revolutionary in my lifetime.
My rights don't need management.
Not necessarily. Build it on a privately-owned island or some such. No regulations, no permits required, etc.
Is there a privately-owned island on or very near the equator, that is at least a hundred miles from any other populated territory?
I'm not asking to be assine, but that is what it would take to completely free of such restrictions. When talking about a ribbon that stretches to GEO, and half of the lenght can potentially fall to earth, the "backyard" in "Not in my backyard" is substantial.
One of the things I find amusing about the space elevator is its need for a fully functional space industry to construct it.
Right now a small private company (Liftport), not NASA or the Air Force, is in the lead on revolutionary space travel.
They aren't the only private company planning independent space travel. For example, Space Island Group is planning to build multiple space stations by the end of the decade. They have a lot of former NASA engineers working for them.
The assumption involved in the "relative" is the difference between the tech level needed to build a space elevator and that needed to build a floating port on the surface of the ocean.
A ballistic missile can hit a very tiny area, and that is essentially dropped from orbit at high speed, not lowered slowly.
"This quote is a product of the Frobozz Magic Quote Company."
LOL. I think we are talking about something more than a zoning variance. Hanging a space station a couple hundred miles offshore is still bound to make a couple of countries nervous. You're going to need some international diplomacy, not just a call to the local alderman.
"Maybe a floating platform, or in an equatorial country that would provide uber-security in exchange for the obvious economic benefits."
Do you know any third-world banana republics that are reknowned for great security?
No, they don't have to lower the whole thing down, just one one thin line at most. Then the construction machinery could climb up.
-
When you lower a cable, it is relatively easy to anchor it to a floating platform in the middle of the ocean. Therefore, there is no worry about equatorial real estate, local population, eminent domain, or other government-dominated nonsense.
What about natural phenomenon, such as a hurricane or two blasting the platform each year?At least, something able to take me up to the 7th sky! :)
Why I'm even bothering, I'm not sure. Although the Space Elevator is an old and wonderful idea that will inevitably come to pass, any mention of it on Slashdot is so annoying because people come up with the most ridiculous assumptions.
First of all you're responding to a guy who is either a troll or a total idiot.
Second, when you buy property you don't own the sky above it beyond a hundred feet and that's being very generous. I own a lot of vacant land and I can't put anything over thirty feet on it. It's owned, paid for. It's all mine. But there are still limits.
Generally speaking, you don't own the minerals beneath the land you buy either. What happens when you buy land is that you are given a list of rights and it is generally quite limited. Owning an acre of land doesn't mean much of shit at least in the US. You can own land and still not even be allowed to camp on it. No kidding. You find owning land is not really all that different from renting once you actually try it. In fact, you have to pay taxes on the land even after you pay it off. That's just the way things go.
So, no, you are completely off the mark. You can't build a tower into the sky just because you bought some land.
It isn't inconcievable that someobody could invent the ribbon technology in their garage....
love is just extroverted narcissism
Tell that to the victims of the previous attempt at a space elevator. That is what everybody is imagining.
I assume it would be built on solid land. If the government has aircraft carriers patroling dry land then I really need to stop paying my taxes.
do they really need to have the wire anchored on a sea platform?
Why not reel it in when it's not in use, and reel it out when it's needed?
LOL. Still LOL.
A space elevator would be a literal Tower of Babel. It would be the world's biggest target. Remember the twin towers?
At any rate, having a solid object coming down from orbit would cause problems for existing satellites that aren't in geo-sync orbit. Ooops
Then I can be bombarded with cosmic rays and become the human Torch! Flame On!
Before you can lower it from the top, you have to take it up there. Yes, that costs less than building it from the bottom up, but unless you expect to find all the material out there and easy to gather, it's not quite that simple.
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Huh? How does the tenth amendment have anything to do with this?
"The powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people."
I don't see how that relates to government funding.
Basically, if you can think of a problem, they've solved it. It will cost about 10 billion dollars to build, and the materials will be available quite soon. Some examples of problems you might think of:
Weather: The anchor on the top is so heavy and is moving so fast that it won't be even shaken. Plus its strong enough to withstand the fastest winds.
Ionization in the atmosphere: Easy, coat it with gold at higher altitudes.
What if a plane hits it? It would survive--its strong enough that it would cut the plane in half instead of having the plane go through it.
"A ballistic missile can hit a very tiny area, and that is essentially dropped from orbit at high speed, not lowered slowly."
The different between a ballistic missle and a space elevator is huge. It's OK for ballistic missles to reach their target travelling over the speed of sound. That will probably not be OK for the poor fellows (or robots) trying to tie down the Earth-bound part of the tether. Also, a ballistic missle is a relatively discrete package; it is only in one place at a time. A tether needs to exist in many places (i.e. space, upper atmosphere, lower atmosphere) and remain stable in all those environments: much harder to do.
Not sure I would be so quick to dismiss the DoD budgeting process or their fiscal responsibility. A few anectodal popular press examples of fiscal excess should not be taken as the rule. (It is actually debatable if the Gov't really did purchase $800 hammers etc, or "padded" the cost of these items to cover larger non-public expenses). So, the DoD method of Planning, Programming, and Budgeting is actually very robust and has a good deal of merit. The system is widely refered to as the PPBS. It has been around since the 1960's and was first introduced by then Secretary of Defense Robert McNamara. "The PPBS is a cyclic process containing three distinct but inter-related phases: planning, programming, and budgeting. The process provides for decisionmaking on future programs and permits prior decisions to be examined and analyzed from the viewpoint of the current environment (threat, political, economic, technological, and resources), and for the time period being addressed." There is both a 5-year and a 10-year horizon for this planning and budgeting. There is a connection between this process and the "big budget." And overruns, well that is another story. :)
For the really curious, here is the process. http://www.dtic.mil/whs/directives/corres/html/704 57.htm
You'd be surprised how much you do get, sometimes. When I was growing up in Los Angeles, a company wanted to drill a slanting well to some oil. They had to get options on the appropriate drilling and mineral rights for every lot they went under, including our house. If they'd drilled, we'd have been paid royalties on everything pumped.
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Not to mention taxes! Geez. How could you forget such a thing? And regulations! Quick, we need some poorly planned legislation that has no hope of accomplishing anything! We need the lefties out there in the newspapers, claiming success and blaiming failures on everyone else!
I don't know who we're kidding here... the government HAS to step in! It just couldn't be done without the government. Without the government, we wouldn't have airplanes, or cars, or.... wait. Well ok, we'd have cars and airplanes. Without the government, we wouldn't have... taxes? Stupid, power-hungry politicians? Socialists who want a single-class society?
If we don't have government involvement, who's going to tax this thing? It has to be taxed. Most of the socialists need to tax this thing, otherwise, the free people will realize that we don't need the government to do this type of stuff, and the elected politicians will start to lose power.
You know, there's a lady who thinks all that glitters is gold, and she's buying a stairway to heaven....so my guess is that the US Gov't wants a piece of the action.
I think you pointed to the one and only reason a government agency would 'need to be' (read: 'find a way to make themselves') involved: Defense.
;~)
A private company would get some flak for firing a bunch of SAMs at any plane which came within 25NM. A government (or consortium of governments) would just issue a press release.
And your only line of defense is to shoot down ANYTHING that comes within about 25 miles of your ground station. Warn 'em from 100, and if they don't divert...
25 miles may seem a tad overkill, but there are missiles out there that travel at mach 5 or so. Pretty expensive defense systems are required to counter those
cheers,
Except if the cable breaks and wraps around the planet 3 times!
"The energy and materials requirements for lowering a cable from orbit are drastically different from building a tower to the stars."
Are you so sure? I assume they'll end up having to build a semi-rigid structure for practical reasons. Getting all of that building material into orbit in the first place would be extremely expensive in terms of energy, material and $.
Fighting gravity is a lot cheaper when all you have to do is drive up to the base and haul it up vs having to launch it. It would also be a lot safer and you can take your sweet time doing it.
I have to wonder how they would build the center section of it though. It would have to hold twice it's own weight (gravity pulling down and rotational momentum pulling upwards) not to mention the weight of anything crawling up it and atmospheric buffeting.
I agree building it in the ocean would be a lot safer if it ever failed and came down (or flew up?).
Somehow this idea scares me, it seems too easy. It seems like if we got enough of these things it would take quite a bit of momentum out of the rotation of the earth.
The best place to pur it is Equador. Athur C. Clarke would disagree but ... Equador is called that because it is right on the equator.
The terrorists would have a field day trying to blow it up, which is why you have to have many and varied international agreements.
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"Therefore, there is no worry about equatorial real estate, local population, eminent domain, or other government-dominated nonsense."
That someone could build such a valuable thing as a working space elevator in international territory and without the protection of belonging to some nation or another - AND THEN - have it remain free of governmental protection without some group showing up and annexing it is not something upon which I would like to bet.
I have to question the legitamacy of the company altogether. The write-ups are of an amateur nature. Verbage and use of the language is poor in many areas and I would question that any company looking to fund that large of a project would present it's foundation of material in this way to the public. Examples are in the FAQs answering questions such as if a ribbon breaks; "Honestly, it will make a little bit of a mess". and other things they say in describing the strenght of the ribbon; "3-5 times as strong as needed", what about correct english as in 3 to 5 times stronger than needed. Some of it seems written at a 5th or 6th grade english level. Certainly not collegiate level as you would expect. And the frank public statements regarding liability would shun and serious potential investor in the group. Of course you can always send in your paypal donation. I see they did take the time and effort to get the 'take your money' part of the website right. Careful here, you might have been scammed.
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Good point -- you build it on the equator for starters: hurricanes don't cross the equator. Second, you pick the place with the most boring, unchanging, weather on Earth. Given platform technology can already hack conditions in the North Sea and Gulf of Mexico, you should be okay for the rest of time. Part of the reason for using a sea platform is so that you can move one end of the elevator cable around (although ribbon would be a better description) so as to dodge orbiting satellites, etc, so there's some flexibility built in.
"Just once, I'd like to meet an alien menace that wasn't immune to bullets." -- The Brigadier, Dr. Who
It smells suspiciously like, "Let's ask the UN!"
Yeah... that's a good idea. Let's ask Syria, Iran, Iraq, Egypt, Afghanistan, Pakhistan, India, North Korea, China and dozens of other 3rd world countries to tell us how to run our country.
Sounds like a bunch of GreenPeace/Sierra Club/PETA/tree hugger crap to me.
I'm tired of people who want the rest of the world involved in our affairs. They don't ask us to be involved in their affairs until there's a war, or they're broke and dying of famine. Then everyone cries bloddy hell about the wealthy Americans who never do anything! Bullshit. We do everything, and we do it without any thanks.
In the meantime, these countries promote the sale of drugs, weapons, terrorism, and they have little thought for "saving the planet". They have dictatorships that rob the country blind, starve their citizens, and yet we're supposed to ask their opinion on a space elevator? Bullshit. Go over to Cairo, and look at the pollution from their automobiles. They don't listen. It's far worse than Los Angeles. Egypt gets 8 billion dollars in relief from the US every year... but what thanks do we get? Angry terrorists shooting AK-47's in the streets and killing tourists?
Nope. I don't want their opinions or advice. Same thing with Russia. They need to clean up their own country. When they can be responsible to their own citizens, and own their own problems, then they can start to tell us about ours. Until then, they can shut the fuck up.
Have you ever taken a very heavy object and swung it at the end of a tether? Cetripital force begins to tug on your arms. Now, think about a cable that is so tight and so strong that it can hold up ships to be brought into space. I imagine a satellite in high orbit would have more than enough force to simply remove that platform from the water. Not to mention the long arduous process of transporting that many miles of cable to an altitude necessary to maintain orbit.
Sheesh, such nonsense. ^^; A moving oceanic platform is the current proposal, and is far preferred above a land based solution which has many many problems. Which the sea one does not.
In other words, goverments are for the most irrelevant. It coming down would also not pose a serious risk, though it gets trotted up each time by some people. The thing only weight a few hundred tons and is thinner then paper.
Quickshot
The proposed site isn't really just some spot in the middle of the ocean- it's some spot in the middle of the ocean, on the Equator. Not only does this make it possible to place a station on the cable at a geostationary orbit, but it confers the added bonus of being in a place where hurricanes are actually extremely rare- hurricanes, cyclones, and typhoons tend (but not always) to originate in belts called Intertropical Convergence Zones that flank the Equator, but do not stretch over it- in fact, the Equator lies in the band of low wind and calm seas aptly referred to as the doldrums.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
Not sure I would trust a company that builds it prototypes from Lego...
Give me a job. Please?
...what a space elevator is, how it would work, and so forth, but really doesn't, check out this link. This is the NASA-sponsored report that basically declared it open season on space elevators. It's fascinating, in-depth, and answers questions such as "how do we build it" and "what happens when in falls/gets holes in it". A must-read for space buffs.
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For the initial elevator ribbon deployment, you're talking about 2 spools massing about 20 tons each, but once you've got the initial ribbon up, you use the cheap, cheap, elevator itself to build up the ribbon, so you're not paying typical launch costs for the whole thing.
To get the initial spools and associated hardware up to GEO, Brad Edwards calculates (if an MPD engine is used for the LEO to GEO transfer) that the launch cost could come downn to about $1 billion for 4 Atlas 5 launches -- about twice the cost of a single shuttle mission.
"Just once, I'd like to meet an alien menace that wasn't immune to bullets." -- The Brigadier, Dr. Who
I'm always amazed at the ideas of Arthur C Clarke; how years after he dreams them up the are implemented. Geocentric satelite, check. Space elevator, check; as documented in his 1979 book The Fountains of Paridise. I love his stuff, just hope Childhood's End occurs anytime soon... ;)
CB$@
free ipod and free gmail!
Why are all you people thinking of a big thick metal cable? It's a carbon nanotube ribbon. You don't build it in orbit, you build it on the ground, wrap it around a spool, launch it into space, and lower the ribbon to the ground.
Think about it. The reasons should not be hard to understand, but I'll give you a hint - objects orbit around other objects centers of mass. A geosynchronous orbit above a point not on the equator cannot possibly orbit a sphereish object with a gravitational center of mass at or near the center of the sphereishness.
Yes, geosynch has to be at the equator.
---
Mod me down, you fucking twits. Go ahead. I dare you.
(I read with sigs off.)
"Now, whoever creates a space elevator is going to instantly become a major, global power..."
You mean like how Panama kicks ass in central america or how Egypt is totally rockin the middle east?
A space bridge would be a big source of income, and national pride. But font of world power? By exactly what mechanism?
Yes, I remember the twin towers. They were attacked because they were symbolic and filled with lots of flammable people.
Did you read what followed in my post after the part you quoted? If you can actually hit the elevator (which will be perhaps a few feet wide, not as easy to hit as a skyscraper) then all you will manage to do is snap off the very lowest portion of it, which is the easiest to fix. Why risk the lives of your agents and spend a lot of effort to attack something that will cause no loss of life and no real damage?
If you feel a need to respond, please dispense with the mindless "don't you remember September 11?" stuff. Argue facts, not emotion.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
1) it's not that long, and 2) if it breaks, only the part below the break falss; the part above flies off into space
If a job's not worth doing, it's not worth doing right.
1) This is a great idea; Nasa should scrap the shuttles and build one.
2) The government shouldn't have a space program. (Maybe the government shouldn't have too many programs at all.) This will be an outrageously expensive boondoggle, and we should just let private industry handle it.
3) Dude, when is private industry going to get around to doing that?
4) When it's good and ready.
5) Dude, private industry wouldn't even build the interstate highway system - a fulcrum of America's economy. What makes you think it will build a space elevator?
6) Communist.
Want to Know How to Cheat the GPL? Read On!
Kim Stanely Robinson has a lot to answer for -- every time the space elevator comes up, people drag up the plot from the Mars books....
To (once again!) answer the objections raised by this scenerio: Unlike Mars, Earth has a nice thick atmosphere. The elevator ribbon has a very low mass per unit length (indeed, this is one of the characteristics that make the elevator physically possible, not just sci-fi). If the cable is severed, only the stuff below the breakpoint would fall to Earth, and execpt for the bottom few hundred miles, would burn up in the atmosphere. The remainder should fall into the sea, and again, because it's so light, any that did somehow hit land would cause any major problems.
"Just once, I'd like to meet an alien menace that wasn't immune to bullets." -- The Brigadier, Dr. Who
See that is where this whole notion goes horribly wrong. The ball at the end of the string is able to display is centripetal effects due to it have a mass in the presence of gravity. The two objects, you and the ball at the end of the string are tugging at each other because of gravity. That is not the case with a ball attached to a string attached to earth. Earth IS the gravitational generator, (at least to the best of our knowledge so far), and hanging anything out there in a synced orbit only falls back to earth and rather quickly. It doesn't gain some fictitious angular momentum unless it previous momentum was angular to begin with and we are talking about the object being synchronous with earth's spinning. The earth's spinning will not generate momentum in the object hung stationary above it. Einstein's own theories reflect this. There are some good theories as to how to make this work, but this is not one of them and the science behind it is simply bad.
Panama and Egypt now are simple means to get someplace a little cheaper than alternative routes. Before there were alternative routes, places like Gibralter and Suez were _much_ more strategic. From the time the first space elevator is built, until there is a competitor, whoever controls that space elevator is going to have de facto gate keeper authority over a block of resources that dwarfs those available on the planetary surface. Think about what nations like Spain, France, Portugal, the Netherlands and the UK did during the "age of discovery". The tiny little Netherlands was for a time a world power-based on its maritime strength. When that race started, it wasn't exactly obvious that the UK would become the hegenomonic power. I can easily believe in this case that someplace like Canada or Taiwan winds up playing a role similar to that the UK played--coming up from behind to seriously surprise the world.
... to terrorists. And I thought two 1400' buildings and the world's largest office building were tempting targets.
Research shows that 67% of those who use the term "research shows", are just making shit up.
Behold, an explanation of space elevators using only playground equipment and imaginary experiments.
First off, if "cetripital" [sic] force is going to have any affect on a space elevator, why aren't satellites flying off into space? The answer of course, is gravity. The space elevator consists of two things, a satellite, held in orbit by the Earth's gravity and its own forward velocity and a cable, extending from the satellite to the earth's surface.
The cable is not some kind of tether by which we're swinging the satellite around, it's merely a cable. Here's an example... Sit on the middle of a merry-go-round. Have someone with a strong sense of balance and an iron stomach sit on the outside of the merry-go-round and run a string between the two of you. Place a washer on that string and get a third person to spin the merry-go-round as fast as they can.
While this is happening, elevate and lower your end of the string, causing the washer to move up and down the string. Observe how the person on the outside rim of the merry-go-round does not go flying off into space. Observe how they do not drag you with them.
That's how a space elevator would work. It's also worth noting that the cable will be (initially) of trivial weight, 20 tons or so maximum. This will be a leader cable, much as you'd run a small string over a tree limb in order to draw a heaver rope over it for a swing. That way you only have to haul 20 tons of cable into orbit (a trivial endeavor with proper financial backing) and can use the cable to construct a bigger, better, stronger, elevator for (basically) free (as in beer).
Killfile(TGK)
No trees were killed in the creation of this post. However, many electrons were inconvenienced.
The difference is akin to dropping a rock and hitting a dime and accomplishing the same task with a plumb bob. The difficulty level is lowered further if you are allowed to move the dime in the process.
"This quote is a product of the Frobozz Magic Quote Company."
Since a few of you are quoting a Wired article, let me remind you all of another article regarding the DOD's stated mission of "Dominating" the space arena and to deny other nations the ability to launch any platforms to space which we would deem to be contrary to our interests. See Wired magazine; "Peace is war" April 2002.
As you might recall from the article, Rumsfeld and others within the DOD have simply stated that space is too important to allow other nations to participate fully without our approval. Period. As an example, consider US lobbying and conditions in regards to the European GPS system.
from the article
Operation of a space elevator will not be allowed where it conflicts with our interests, this includes business interests too. Any venture providing access to space would most certainly have to have their payloads approved by the US government, even if the launching platform is 5000 miles out into the pacific somewhere.
Seems pretty clear, even if a private interest were to attempt to create a space elevator, they might find an un-invited "partner," regardless of their wishes. Soooo, might as well go with the flow and accept the DOD money right off the bat. No other way the project's gonna get done.
It's worth noting that a space elevator has enormous military potential and consequently will (inevitably) be both a valuable asset and a prime target for whomever manages to build it. Once you can haul heavy stuff into space cheeply you can drop heavy stuff on people from space cheeply.
Realism dictates that someone's gonna want to get their hands on this to bomb the crap out of someone else. It's just a matter of time. As a consequence, something like this needs to be heavily defended at all times by something fairly neutral.... I'm not sure even the UN qualifies.
Killfile(TGK)
No trees were killed in the creation of this post. However, many electrons were inconvenienced.
The main problem with the Department of Defense is they:
1) Take the lowest bidder. Not the best bidder, not the most cost-effective bidder. Just the lowest. Because when Senators and Representatives look at the budget, all they look for is the dollar sign and the numbers following it. There's too many corporate parties to go to when you get to that point, and you only have time to do a half-assed job on 100,000 things.
2) This year, they've (Congressmen and women) only got time to do a quarter-assed job on 300,000 things. They've gotten more efficient, but the number of issues has grown.
3) The contractors they hire to make the parts are geared to deal with security clearances.
---
For some of the stuff, they need to just accept the risk of the "security breeches", and engineer a way around them. Rifle bolts, tank shells, toilet seats, wrenches. You're better off hiring engineers to test random batches for quality control, and analysists to worry about what the enemy can gleen from the information.
Lemme just say we don't want the lowest bidder on an elevator. We don't even want cost-effectiveness; we want something that will last. We want to be able to launch 1000kg satellites, at will, for 20 years.
Someday these things will be wireless.
Speak truth to power.
But... You could build a space elevator with a non-geosynchronous orbit. Say for an extreme example, you anchor it to the north pole, and swing it around once every 24 hours. The cable will appear to point in the same direction, parallel to the ground directly at the pole all the time. The forces on the cable will be different, and it will fling whatever is launched from it along a completely different orbital path, but who is to say that is a bad idea? There are many reasons why you want non-geosynchronous orbits that go from the northern hemisphere to the southern. This would allow for that without requiring additional thrusters as it would take launching from a geosynchronous space elevator.
Don't get caught thinking one particular way, and assume you _need_ a geosynchronous orbit.
-Jesse
Nothing says "unprofessional job" like wrinkles in your duct tape.
Here's a hint: if you're using it to move cargo into space, there are going to be people around it to load that cargo onto it. And lots of expensive cargo on the ground waiting to go up.
And I don't think you understand the minds of terrorists very well if you think that the WTC and Pentagon were chosen because there were a lot of people in them. The symbolism is important. Crashing a plane into a football stadium would have had more potential for killing lots of people than the WTC or the Pentagon. But a football stadium isn't exactly the gigantic symbol of American economic or political power.
Don't blame me; I'm never given mod points.
"Why risk the lives of your agents and spend a lot of effort to attack something that will cause no loss of life and no real damage?"
Headline: Terrorists Snap Space Elevator
Subhead: Dozens Killed at Tether Platform, Hundreds Stranded on Space Platform
Pullquote: "Our shuttle fleet stands by to effect a rescue if needed." - J. Rogers, NASA Bigwig
I still don't buy the business of a broken tether being easy to repair. A space tether is a long, long thing. If a little thruster can nudge a shuttle around in space...just think what several hours of high atmosphere winds could do to a dangling tether.
Argue facts, not emotion.
Again, you forget we live in a political world. Politics is almost all emotion. You need a political solution to get a space elevator built...so emotion is important.
Ok, I flipped through the site and couldn't find answer, so I'm going to ask it here and absorb the flames. What holds the orbital end up? Before you say "Nothing... it's in microgravity.", I know. But anything thing that tugs on the ribbon is going to pull the endpoint towards earth. It seems to me that that should have been the first question answered on the FAQ.
Let's see
The government likes to send things into space
The government isn't likely to develop a new technology to send things into space cost-effectively
There is a company that wants to develop a new technology to send things into space
How about the government just promise to use those guys if they prove to be cost effective? I mean a lot of the problem with public funding has to do with people funding things that do not work, or go over budget, in effect, allowing subsidies to make companies take on some of the worse fiscal aspects of public funding.
Why not just reward people who do the right thing, once it's proven they can do it?
And yes, right of ways, air corridors and related ideas are all things the government can help with. But, let's agree to do it as indirectly as possible, lest
1) the project be tainted by political ideas
2) the project become less efficient
These people want to turn a profit, let's lend em the money to do it, and promise them clients, that's what new businesses need. Let's not promise to bail them if they fail, and perhaps, they'll only try once they're sure.
If you can actually hit the elevator (which will be perhaps a few feet wide, not as easy to hit as a skyscraper) then all you will manage to do is snap off the very lowest portion of it, which is the easiest to fix.
First, I don't think you can just sew it back together. AFAIK there's no "fix" for a broken ribbon.
Second, if the ribbon is completely broken, the top will go flying into space. Its not just going to keep hanging there above the platform.
IOW if it breaks, you're back to square one (plus the experience).
We still have a disagreement regarding scale. Our plumb bob in the tether case is not to be built with string, nor will it have a "hand" which is allowed to move much, nor do we have an overweight "bob" at the end of the tether.
I would suggest a different example to suggest the relative difficulty: hitting a certain tile on the bottom of a swimming pool with a length of sewing thread.
Why would it wrap? It is travelling the same speed as the surface of the Earth. It would fall straight down, no?
"I'm not impatient. I just hate waiting." - My Dad
Never said that, and if you read the NIAC report, you'd know it isn't necessary for a cable to be aligned geosynchronously. That was nothing like my point.
However, geosynchronous orbits by necessity orbit over a equatorial point. This is physics, and is non-negotiable.
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Mod me down, you fucking twits. Go ahead. I dare you.
(I read with sigs off.)
...with small private companies is that they are typically hotdogs. They tend to *think* they can achieve something but in many cases can't. To do something worthwhile, one of the requirements is to have the power to do it. It's like those small towns that wire up with fiber to each home. Big whoop. They still have T1s feeding their fiber lines or maybe a T3. The fiber is wasted. There is also no real valuable content created within these municipalities, so the fiber isn't used to shuttle vast amounts of data between each home and the city offices. It's just a huge waste of money for bragging rights. The same will go for any small company that does make a "space elevator". They might do it, but it will be damn near useless. It won't get done right unless it's a public works project or some big corporation can profit from it and sets up their own. Mark my words, I don't expect to see this go much farther than the "we're gonna be on the ground floor" stage. Hmmm... actually, that's probably exactly where they willbe and where they will stay: the ground floor.
Un-news
"I claim this land, err, space, the United Space of America."
"What the superior man seeks is in himself; what the small man seeks is in others."
- Confucius
Read their site. Theyr rely on centripital force to keep the cable taught, otherwise there would be no tension on the cable. They plan on putting the satellite outside of goesynchronus orbit.
http://www.liftport.com/research1.php
The terrorists would...
I really hate that usage. It implies that there is one set group of terrorists (the terrorists), and if we could only just find and eliminate those people, we'd all be safe. News flash: people become terrorists, terrorism will always be a problem to deal with.
What's wrong with dropping the definite article? Terrorists could attack many a target. "The terrorists" is only useful if we have already established which terrorists.
We may not imagine how our lives could be more frustrating and complex—but Congress can. – Cullen Hightower
you pick the place with the most boring, unchanging, weather on Earth.
So, Norwich then?
Its not synched orbit, they put it outside of synced orbit and the only thing holding it from hurling out to space is the tether.
http://www.liftport.com/research1.php
Lowering a cable will pose many variable problems to do with weather/wind/air traffic/troublesome kids. For one, i dont think a space station could be that stable in orbit to have it so a REALLY strong wind wouldn't be able to push it off course and then some drastic evacuation procedure would have to take place. As said somewhere else in the thread, air traffic would be a huge problem. And before anyone suggests it, having lights on most of it might work if you can find a way so the lights never burn out because someone would have to get up there and fix them. And using the elevator to do so might be tricky because it has to be in an air tight environment if it wants to be in space. I don't believe that a "space elevator" is really possible and never could be stable. Which SHOULD be a main concern of everyone, if the tower somehow collapsed from whether, a malfunction. It would fall somewhere, and its path would be destroyed for about 200km or something along those lines. A cable isn't practical and a "tower" will never be safe.
No, many people have proposed that putting it on the ocean would be better. Especially because a space elevator must be on the Equator, and the Equator is mostly ocean.
You have to remember that space elevators are mostly supported from the top, not the bottom. Don't imagine a tower which goes up to the heavens, imagine a rope hanging from a sattelite.
"Never attribute to malice that which can be adequately explained by stupidity." -- Hanlon's Razor
The difference is akin to dropping a rock and hitting a dime and accomplishing the same task with a plumb bob. The difficulty level is lowered further if you are allowed to move the dime in the process.
Now realize that we're talking about a thousand-mile plumb bob, subject to varying winds at all levels of the atmosphere, and it becomes somewhat more complex than the plumb-bob-and-dime analogy.
A space elevator would be a lousy weapon. Namely, because it is an incredibly easy target. Perhaps in peacetime the military would use it to launch satellites, but the idea that people are going to rely on space elevators in wartime is kinda crazy. It's hard to think of a target much easier to sever than stressed-almost-to-the-point-of-breaking paper-thin object which you can access either from outside geosync, at geosync, below geosync, in a suborbital trajectory, in the atmosphere, on the surface, or - in the case of Liftport's design - from underwater.
There's only one thing I hate about Halloween, which is...
First, I don't think you can just sew it back together. AFAIK there's no "fix" for a broken ribbon.
I've heard the opposite from quite a number of fairly knowledgeable people when discussing this subject. I've never heard your position before your post, although that doesn't necessarily make it wrong. I admit I don't know enough myself to say for sure; maybe at this point nobody does.
Second, if the ribbon is completely broken, the top will go flying into space. Its not just going to keep hanging there above the platform.
Actually, it is. Even if you posit a fairly high-altitude attack with an airliner or a missile, you will cut off, at most, maybe ten miles of ribbon. That works out to less than 1/2000 of the length. Since the ribbon has an exponential taper, it will end up removing much, much less than 1/2000 of the weight, and the center of gravity of the whole thing will barely move at all.
Remember, a space elevator is neither a tower nor a suspension bridge. It is anchored simply to keep it from moving around under winds, small disturbances, etc. but the elevator itself is in orbit. If the anchor is removed, the elevator will stay. Removing a few miles at the end of the elevator is extremely close to simply removing the anchor, and so the rest of the cable will basically stay where it is. It may begin to move slowly, but it's nothing that couldn't be corrected with some small thrusters.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
A geosynchronous orbit is any orbit with an orbital period that matches the sidereal day, which is 23 hours 56 minutes and 4 seconds in length, and represents the time taken for the Earth to rotate once about its polar axis relative to a distant fixed point.
A geostationary orbit is a special case of a geosynchronous orbit where a satellite appears stationary from the point of view of an observer on the Earth's surface. The conditions for geostationary orbits are:
- The orbit is geosynchronous
- The orbit is a circle
- The orbit lies in the plane of the Earth's equator
The terms are incorrectly used interchangeably...A couple of other handy facts:
Have you thought for yourself today?
concept would allow shooting radioactive waste to the sun. That would help with the cost of the thing.
In triplicate. Oh yeah, form 29B/6 has been superseded by form 29C/3. No, we do not have any such forms yet in this branch; they are still at the printers. No, you cannot release a spacecraft without a 29C/3, what kind of sloppy operation do you think we're running here!
Sorry, neither. But you're entitled to your opinion.
According to who's laws? Remember that US spy plane that got shot down over the USSR in the '60s? I'm pretty sure it was flying more than a 100 feet above ground.
And what about a couple o' years ago, when there were all those attempts to traverse the world in a balloon. That millionaire couldn't fly over Libya(?), anyways, some nation in Africa, and I believe that China also had issues with him, and again I'm pretty sure he was more than 100 feet above ground. (Sorry, but I ain't gonna do the Googles' to find the info; I need to get outa here, and just want to respond before I go).
Do you consider Brazil to be a banana republic? Papa-New Guinea? Indonesia? While not necessarily 'safe', they ain't 'banana republics'.
Sorry, man, but your narrow-minded world-view is showing.
I gotta go.
(tig)
Ignorance and prejudice and fear
Walk hand in hand
I thought *Arthur* owned this idea. Hey, he invented it. I don't care who makes a space elevator , if it
can be made then
a: it will cost.
b: It will make the historical thing about the panama
canal look seriously easy. Go become a good historian (hint: don't invest).
c: It won't happen real soon.
But, we can do some of this technology slowly.
Perhaps not on the same scale , but Arthur himself
understands that atomic bond limits make it unlikely that we can do it as far as we'd like to see.
He likes to dream. That's why we love him. Heck. He did get it right a few blinks of a chickens
nose ago, and couldn't patent it.
Never underestimate how much we love Sir Arthur.
If there was any justice in the world he wouldn't
be an ill man in a wheelchair. He'd be a passenger
on spaceshipone. He deserves it. Please Mr. Rutan,
you know he wouldn't care if he got back to the
ground breathing...
I for one would *love* Arthur to be our first hacker in space. But I'd love to suggest that he
has to take the ashes of his New York nemesis
up with him. Even though Ike hated flying.
Hey, Arthur. Consider it your revenge.
Do slashdotters understand this old timers joke or
not?
Sorry, you'll have to take down your space elevator. It violates our signage ordinance...
Don't blame me, I didn't vote for either of them!
Well, I imagine it could be a project like the Panama Canal. There you had a (newly formed for the purpose) banana republic, with a world power maintaing stability and guaranteeing security in exchange for creation and use of the canal.
"There's no set architecture in Linux. All roads lead to madness" -Microsoft
In this, the magazine notes (not a direct quote): Once a strand is put up, you can have very light objects climb the strand... this is similar to the first strand placed to wire a suspension bridge. It's very cheap relative to trying to wire the entire weight of the cables. This makes it much more inexpensive than you think
Note also that the article mentions it might be as little as $6 Billion to build it. I think the venture capital industry would laugh at $6 Billion - that's the easy part... the tough part is the science to ensure it can work.
Am I the only one who thinks the whole thing is a dumb idea and a waste of resources? Why build a space elevator when you can just fly there. The more time you spend on learning to fly in space the better the technology gets. I keep thinking some alien is going to show up laughing at all those elevators sticking out from the earth. It's dumb like using wooden wheels
did you forget to take your meds?
So, this means that everything that goes into building it will have to get up there first.
No, only the first strand of the ribbon needs to get up there first. Once its lowered and anchored, the rest of the strands are built going up. A "climber" is used to unroll the next strand of the ribbon as it climbs the first strand. It will take years of adding stands in this fashion to finish the elevator.
The added bonus is that once that's done, building a second elevator is cheap because you can use the first one to send up the starting material for the next one.
I would reply but I am busy Googling for cheap, equatorial, island real-estate. Cheap real-estate...Gotta do it quick before everyone else thinks of the same idea.
Now where did I put my Visa card...
Veritas patesco per quaestio questio. Truth is revealed through questions.
Only on Slashdot would attaching a cable from orbit be considered "relative easy" and get a +5 informative.
You would need approval from all the major world governments before you even attempted such a feat. This isn't the movies.
What sort of speed will this thing have? 60,000 miles seems a long way to travel...
Also how does it get down? If it is powered by gravity KABOOM - it would need some powerful rockets to slow it down because I shouldn't think it could grab the rope to slow down.
MONORAIL, MONORAIL!!!!!!
Yeah, that sounds like government budget planning all right.
Just to follow up from this, sounds like you're right. From http://liftport.com/research3.php
"Terrorists are unlikely to be able to break the elevator anywhere higher than 15 km or so; it can then be simply flown back down to the anchor by moving some of the counterweight mass a bit further out and will be back in operation in a couple of days."
Though they're not so much sewing it back together as they are trimming the end and re-anchoring. Good to know its so easy to fix.
This empty-headed, libertarian free-market dogma astounds me.
Which mccarthyite is going to claim that government involvement == waste? Who? Which private enterprise advocate is going to suggest that waste doesn't exist in *all* enterprise.
Large organizations have chaos. Chaos == waste. No private entity is without chaos.
Trying to suggest that organizing to implement a mandate that embodies the will of the public (ie: Government program) is wastefull is idiotic.
In spite of what that the predominantly US audience of this website believes (in error), the world is populated with many MANY social democracies. Many societies that are (easily) arguably superiour in MANY aspects to USofAmerican culture (i know you are find that notion alarming, but trust me, there are many nations with higher standards of living, better educated, better health care, better environments, better X, Y, Z)
ONLY in the USA is the free-market dogma so entrenched. Your precious free market is A) Fiction and B) Impossible. There is and will never be a completely Free Market -- trying to achieve one (which is unnatural) will require all kinds on nonsense contortions that breed stupidity like this article's lead-in above.
If you believe that that blind adherence to McCarthyism is going to lead the USA out of its present hell-bound trajectory, I'd suggest you reconsider.
Its time you Americans stop and consider that maybe someone else might have happened upon a good idea. One of those good ideas happens to be not mistrusting government prima facie. Further, the selfish suburbanite middle-class, in their cushy houses and SUV parking lots had better wake up: The middle class only exists as a result of the Welfare State. Remove the involvement of Government in protecting Workers rights to a fair living (ie: middle-class lifestyle) and you get a polarization of wealth that existed in the times of Railroad tycoons. Beware, this is exactly what you have been asking for.
Mistrusting USAmerica's Plutocratic government is a good idea for the masses -- buying their dogma (anti-government/anti-cooperation) is suicide. Believing the libertarian fantasy that free markets == freedom -- that ordinary people would be more prosperous with "less government interference" -- is the point where I can do nothing more than shake my head.
I think his point is that the Constitution limits the federal government to exercising only those powers granted by the Constitution, instead of the status quo which is whatever they can get away with. I'm sure that /. posting is interstate commerce.
English is easier said than done.
Even at extremely high speed it is a very very long distance for an elevator. The boredom of taking a week long trip on the transiberian railway is nothing compared to it. I don't think elevators scale wel over distance. With an elevator MTBF of 100.000 miles (and with 20.000 miles to go before next repair station) you wil soon run into trouble, even if you throw away the elevator after each lift. What will you do blocked between first and second floor and 10.000 miles form nowhere?
Anyway, by the time it is build the competition wil have reduced its price by 90%, that's 98% compared to a spaceshutle.
What if the continent of Australia goes on a drinking binge and decides to take the elevator into space. Would this tend to slow doen the Earth and cause longer days?
..........FULL STOP.
The symbolism is important.
All the more reason to make sure that the American government doesn't have a fucking thing to do with the elevator. Or any government for that matter, with the possible exception of a place like Canada (whom no one seems to hate).
Max
My god carries a hammer. Your god died nailed to a tree. Any questions?
Alright, I'm narrow minded. No doubt eh. I'm so left I'm a fascist as well. But let's not spend too much time talking about lil ol' me.
What the hell do national airspace rights have to do with private property rights? The latter are very limited. I'm sure on this one. I've been calling various officials for months trying to develop this parcel and I'm telling ya, it's not like you would think. You don't own anything that isn't explicitly granted to you by contract and in the end it is the government you are contracting with. All land contracts in the US orginated with the US government at one time or another. When you do a title search, that's where you go back to.
As for the post about mineral rights. Well, it does depend but when you're talking about small pieces of land you definitely don't have any mineral rights by default. You don't get shit by default except the right to pay taxes. Again, it's all about the specifics of each contract and, once again, in the end it is the government that authorizes that contract.
Let me explain it like this. The income tax is a relatively new idea in the US. So, before the income tax, where did the gubbmint get the money? That's right, they sold real estate. So, see, the government in the US is the original owner of the land and they set down specific contracts for each parcel about who gets what rights. You don't just buy it and get your own little nation. That's just now the way it goes.
So back to the tower thing, no, a private land owner can no way in hell build a tower of unlimited height without government approval. No freakin' way.
As if it mattered. I mean come on, you'd have to have a hellish supply of toothpicks and peas.
Fortunately, this plumb bob is large enough that it would be easy to attach all sorts of stabilization devices directly to it, making it much easier than what you're describing.
Hey, dude, the very TCP/IP internet you're now enjoying, not to mention the interstate system on which you're driving, are direct products of this government you're myopically sending down a very progress-retarding policy path.
At a high enough level of abstraction, the government functions as a power supply for progress, albeit a corrupted and frequently brain-dead one.
But that's more a function of the ballot box feedback than anything else.
Maybe we should all write in Lessig in November...
Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
After the first elevator goes up, it would be almost trivial to build more. So it would only be *the* space elevator for a very short period of time.
-- Give me ambiguity or give me something else!
Once they have built the smaller prototype, they can scale up with the "duplo" style blocks. They've always seemed like Legos, but for kids w/ "special" needs..
Anyway, I thought I was the only one who caught that. I'm not sure if I like it or not
..........FULL STOP.
What keeps the elevator up if I were to tug on it? To lift a 1-ton satellite into orbit, the elevator must exert 1-ton of force opposite to the pull of the satellite, if my understanding of physics is correct. So what keeps it up?
To get the initial spools and associated hardware up to GEO, Brad Edwards calculates (if an MPD engine is used for the LEO to GEO transfer) that the launch cost could come downn to about $1 billion for 4 Atlas 5 launches
So the ribbon goes up in 4 pieces, which are then tied together with, what, granny knots?
Weeks of coding saves hours of planning.
Encourage private investment in companies which will build and operate it, then sue the companies for anti-competitive practices when they charge extra to get a return on their investment. Once the companies go bankrupt, sell the elevator at a greatly defleated price to new companies which will operate them for less. The only ones who loose are the suckers-I mean the venture capitolists.
This is by far the most witty (image only) reply to a thread (taking the whole thread into account) I've ever seen on Slashdot.
Or maybe I just like art...
Kudos!
BASEE Jumping;
B.uilding
A.ntenna
S.pan
E.arth
And now:
E.levator
And if you're manufacturing the ribbon at the space end (which you'd probably like to, since most of the materials suggested are easier to make at a high quality in free fall), you can then just spool out a few more km.
I am TheRaven on Soylent News
Someone must have told you centrifugal force isn't real. But whomever did that didn't explain centripetal force properly. Centripetal force is the force that resists centrifugal force. Thus, it pulls into the center of the Earth. It cannot fling you off.
Especially the part where the space elevator comes whooshing down and wraps around Mars several times.
Glad we aren't planning on making anything like that...err...
Air traffic wouldn't be anything like the major problem you seem to think it is, unless they built the elevator in secret and then periodically moved it to mystery locations along popular air routes it's going to be a well known and easily avoided obstacle.
As other people have said if it did break it will not be the major disaster you are portraying because:
1) It's in the unpopulated Ocean
2) The cable is not strong enough or big enough to hit the ground in one piece, either it will burn up or break up into small pieces.
I like the idea of a space tower but it's a lot less practical than a cable !
A. There arn't very strong winds right on the equator its rather calm.
A1. It will be slightly higher orbit then geosync in order for there to be tension on the cable and to support the weight of whatever it will carry up, think its constantly pulling X weight up from the ground, but we can secure it that tightly. Its maxium weight you can put on it will the the same X, otherwise you will be pulling the satallie down. Hopefully we will have some altitude control so that we can adjust X as needed, though you don't want to risk breaking the cable.
B. Air traffic over 1 very specific point on the equator, thats like saying air traffic over the whitehouse is a problem. Yep, you just don't fly there.
C. Lights on it, hu? Oh you mean the air traffic, as a said it doesn't move much, its simply a no-fly zone. Fly here and you get shot down, understood...
D. Having a couple hundred tons of ribbon fall will have a very low maxium speed due to air resistance. Most of it will burn up otherwise. Think no one part of it will be very heavy.
OK. However, neither "space escalator" nor "space conveyor belt" have the same "straight up" connotation.
That was the number two location, but they decided to go with a patch of ocean a few hundred miles west of the Galapogos as number one.
"Just once, I'd like to meet an alien menace that wasn't immune to bullets." -- The Brigadier, Dr. Who
Really, what's the last major civil engineering feet that has been done that hasn't been government sponsered? Or how many particle accelerators are solely privately funded. The costs are just way too great for the private sector to tackle it. The payoff is too far down the line. The costs are too great and the risks way too high.
This is no different than taking on the Suez/Panama Canal, St Lawrence Seaway, Chunnel, Hoover Dam, Big Dig or any other huge undertaking. It needs to be driven by someone who has huge backing but doesn't have to turn a profit from the work before the next board meeting.
I know, this is slashdot, and the government is evil. I'm certainly not pro government myself, however, for the unforseeable future it'll be the only way such things that takes many years and costs billion is ever going to get done.
It may not be quick, or the cheapest, but it's usually the only feasible option.
And I'm one of those scary green preservationists the GOP warned you about.
No, let's not. Not that you're not relevant, but that you're not the issue. (Hope that isn't insulting, it's not meant to be.)
And here seems to be where the confusion/misunderstanding arises. I'm not necessarily talking about the US. I'm talking about the best place to build a tower/cable that stretches into space. It was mentioned that with such a structure that its' neighbors rights/opinions would matter quite a lot. Agreed. Which to me seems to all the more reason to build in some remote area, such as a floating platform, or island. Seems security would be easier under such conditions as well. Make all approaches (air, water, land) off-limits to all but authorized vehicles. The sole purpose of the island/floating platform is for this tower/cable structure. The only residents are those who work there, and perhaps a few supporting businesses (such as a bar
Anyways, interesting discussion, and I appreciate your input on US ownership laws.
(tig)
Ignorance and prejudice and fear
Walk hand in hand
Did anyone end up buying this one?
Real Daleks don't climb stairs - they level the building.
The ribbon goes up as two full-length spools, which are bonded together as they are unspooled to create a single initial ribbon with a 20 ton lift capacity. 4 launchs are required because in addition to the spools, theres the rest of the the hardware--the descender rocket, the spool unreeler/counterweight station, and the LEO to GEO transfer engine.
"Just once, I'd like to meet an alien menace that wasn't immune to bullets." -- The Brigadier, Dr. Who
Good question. I'm not sure if there is some tension kept on the ribbon, meaning that cutting the ribbon would make the elevator pull away slightly, or if it's some odd consequence of orbital mechanics that makes it all work out properly.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
What keeps the elevator up if I were to tug on it? To lift a 1-ton satellite into orbit, the elevator must exert 1-ton of force opposite to the pull of the satellite, if my understanding of physics is correct. So what keeps it up?
The simple answer is "centrifugal force". It's simply the fact that the elevator is *that* long, and it's rotating very quickly for something *that* big.
For people who are smart enough to realize that centrifugal force is artificially caused by a frame-of-reference issue, this may seem a little fake. Then you have to realize that when you say "pulling it down", you're talking about speeding its rotation up, due to conservation of angular momentum. (The force you're exerting is radial - therefore, no torque, as torque is force cross the radius, and since the two vectors are colinear, the cross product is zero).
So you pulling on it causes it to speed up (causes it to lean westward) but it does it so slow that you'd barely notice it. Of course, if it stays static, that force has to come from somewhere - and it comes from the anchor, pulling eastward on it (and slowing the Earth down).
So the grandparent is correct, in that the elevator is anchored to keep it from moving around, but that's only true when it doesn't have a load. If it has a significant load, then the anchor is keeping the elevator in place. If the elevator is struck then, it would move quickly. Of course, the payload could be jettisoned, and the elevator would then be safe again.
I completely agree, there is no way any private company on it's own is going to get anywhere with this. Government intervention and encouragement is the only way we'll get one of these.
According to who is Liftport in the lead on space elevator technology? As far as I can tell, this company is just a few of geeks who played with lego mindstorms and set up a fancy webpage. Their site hasn't changed in a year, and their team consists of mostly administrators who write blogs about unpacking and filing things. Their Liftport group umbrella has almost as many companies as employees. What have these people done that makes anyone think that they have more of a chance of building a space elevator than my kid brother Joey?
LS
There is a fine line between being a cultivated citizen and being someone else's crop. - A. J. Patrick Liszkie
Now, obviously the top of these things is much harder to attack than the base, being in outer space, but there are plenty of launch vehicles powerful enough to send a fairly large bomb or small nuke on a one way trip to the top.
That being said, I still think space elevators are a better, safer, cleaner bet than rocket propulsion if we're serious about building our space infrastructure.
Or just one Vulkan/Hercules, probably with plenty of space leftover...
Also a quote from the same site (a little biased, but what the heck - this is slashdot...): "Some people say revive Saturn-V, well this is a 40 year old rocket design! The costs of reviving this rocket would also be prohibitive. Besides NASA apparently lost the plans! In any case, Saturn V is dead and buried."
The key is, that your friend is descibing the SQUADRON budget, not an RD budget. As a budgetary cost center, yes the squadron has incentive to spend what it can, or it may lose it in the future. When you look at large organizations, this is a reoccuring problem and is quite famous.
:)
However, research budgets are much different. The budget is distributed to a large cost center, such as space elevator research program. It is then distributed into smaller chunks by a program manager, who assigns priority and checks progress. Although the manager probably will distribute all the money for the same above reasons, each indavidual project suffers from this less.
Why? Because the manager watches indavidual efforst likea @##@@@ hawk for waste, infefficiency, and graft. Ever project will have a strict time scale it needs to be completed. Every resource used must be justified. Milestones along the way must be met, or FUNDING CAN BE PULLED AT ANY POINT, and given to a competitor.
How do I know this? Unlike most on this list, I am not a Unix guy but a biodefense researcher. I have worked with DARPA, DOD, ONR etc on many occasions, and this is true for each organization. The rules applied to my University research group are the same for my collegues in industry. I have seen populations from both groups have funding cut for over-zealously budgeting or missing milestones. So, although it sounds cool to say "THE GOV IS INEFFICIENT AND WASTES TONS DOLLARS" the reality is that this happens less than you think. If you look closely, that is. But, hey, I am not cool and that is probably why I post in a news for nerds forum...
My two cents
-Iowa
"He who laughs last, didn't get the joke."-Cap
of the "tie-end" of the helium balloon and the gas rushes out with a loud whoopie cushion-like sound.
Interested in a Flash-based MAME front end? Visit mame.danzbb.com
Just to correct that one trope: NASA has not lost the plans for the Saturn V -- although many paper copies were destroyed, a complete set of blueprints exists on microfilm in Marshall.
The real problem is that the plans for the assembly lines have probably all vanished: all the custom jigs and other tooling created and built up for the Apollo program. It's one thing to note on blueprint that, say, a Saturn F-1 engine outer housing needs to be sintered to the cooling pipe network in one go, but how on Earth do you actually do that?
"Just once, I'd like to meet an alien menace that wasn't immune to bullets." -- The Brigadier, Dr. Who
It should be private. Anybody honest who's dealt with government contracts can tell you it would be overbudget and take twice as long if the government got involved. It's a daunting task, but nothing a (truely) free market couldn't handle. The only trick would be finding a free market.
Liftport accepts donations through PayPal... sounds real professional!
Assuming it's in a geosyncronous orbit, a space elevator's cable will have to be several times longer than the ciurcumference of earth. If it falls it will wrap itself *around* the equator. So, no, putting the platform in the ocean, while a good idea, does not get rid of the risk of hitting a population with the cable in a disaster.
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
If you sever the elevator at any point along its length, the inner segment will fall and the outer segment will be flung outward Therefore severing the cable with current weapons that can only strike in the atmosphere or maybe low orbit, will result in less than 200 miles of elevator striking the ground. The rest is flung away. So if you moor it somewhere desolate, the damage is minimal (the loss of economy on the wasted project, however, is crippling). The bigger risk is sabotage using the elevator itself to help the sabetour. Imagine if someone plants or carries a bomb in a load going up the elevator, and it's timed to go off when the load is most of the way up.... if the bomb sucessfully severs the elevator, then the majority of the elevator will crash to earth - and it's longer than the curcumference of the equator so that means a big ring of destruction all the way around. That's the bigger threat to deal with.
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
I must congratulate liftport on the increidble amount of human-readable information on their website. It's virtually free of corporate/governmental FUD. Just take a look at the FAQ!
I've never seen a goverment organization or private for-profit venture be so brutally honest. It looks like liftport will have the means to pull this thing off provided that the money doesn't run out before their launch date. IMO, the government should be giving out grants to companies like this. It certainly fits in with the goals of both Bush and Kerry. (Bush because it's private enterprise, and Kerry because it furtheres science).
Take a peek at this quote to see how honest they are:
# Will the ribbon produce an electrical current?
The last space shuttle-tether experiment, which unspooled about 19 km of cable, generated thousands of volts of electrical potential and kilowatts of power, burned through the insulation of the cable, and generated a tremendous explosive arc of electricity, that snapped the tether. Now imagine a 100,000-km-long cable and its electrical-generating capacity and you begin to see the disastrous potential.
They also seem to have done a lot of worst case scenario planning as well.
-- If you try to fail and succeed, which have you done? - Uli's moose
A space elevator does not need to be anchored right at the equator. Its center of gravity must be in geostationary orbit and therefore over the equator, but it does not need to be anchored there.
I know someone worked out the theoretical engineering and showed that you could build an elevator up to several degrees off equator, but now I can't seem to find this data.
"If lightning DID hit the ribbon, it would probably break. But don't worry, we have pretty good safety and recovery plans."
Is this the same plans as their "secret" security?
>The ribbon goes up as two full-length spools, which are bonded together as they are unspooled to create a single initial ribbon with a 20 ton lift capacity.
Nope -- the initial ribbon is much weaker, and is built up to 20-ton capacity over ~2+ years by climbers with their own spools bonding additional strips.
>The elevator ribbon has a very low mass per unit length (indeed, this is one of the characteristics that make the elevator physically possible, not just sci-fi)
Specifically: KSR's Mars cable is 10 m diameter, total mass 6 billion tons
Edwards' reference design: ribbon roughly 1 m by 1 mm, total mass ~700 tons
Perhaps these guys are just mimicking some dodgy old anime which never got off the ground? Look it up on google some time.
>And if you're manufacturing the ribbon at the space end (which you'd probably like to, since most of the materials suggested are easier to make at a high quality in free fall)...
Handwavium detected. The only material known with adequate strength is single-walled carbon nanotubes -- maybe in a composite matrix, maybe braided, maybe continuous. The new length record for continuous low-defect CNTs is 4 cm; it's early days.
Nobody has done any work on CNT synthesis in free fall, and there's no prima facie reason to think that would make it easier: neither gravity nor gravity-driven convection is very relevant to the thermodynamics of hot carbon vapor.
You may be influenced by (1) earlier space elevator proposals (and the Red Mars treatment)with MUCH more massive cables, which favored using a carbonaceous asteroid as source and counterweight... and (2) a few decades of overselling about wonder materials made in free fall.
The latter may indeed become important once there's serious lab -> R&D -> manufacturing capability in orbit, but so far they're just tantalizing.
It costs a fixed amount of work to move a 100kg (or any mass) payload 1m (or any other constant distance) anywhere in our universe (so far as we know). Any technology that is reuseable can potentially do the work, so you must look at the costs and risks of the tecnologies. A space elevator has cables which provide a huge surface area against the atmosphere, a system we don't fully understand and a system which impacts every other system on our planet. We don't know what the impact of that could be, but it has the potential to shift weather globally, intentionally or not. You have environmental forces acting on the cable throughout it's length, and you have temprature differences acting on the cable throughout it's length. All this energy entering the system msut go somewhere, and most of it isn't in a form that can be readily applied to propulsion. You have a temprature difference of at least 100c between the base and summit, and probably more than that. You have a potential difference along the whole thread, which means electrons are going to want to flow, destructively or not. You might be able to use this as a power source, but more likely it would be random and difficult to control. You have corrossive forces acting against the cable, and the entire structure from ground to top must be actively maintained and monitored. The platform must have thrusters. The corces applied to the cables will turn the cable into a giant lever. the platform must expend energy to counter the force of the lever. The platform, however, has to use pure thrust to accomplish this, there isn't a simple machine it can use, and gyroscopes control only attitude, not position. I'm not saying this is a bad idea, or that it's not possible, etc. But there are a lot of technological problems with it that would need to be ocercome. The article says "Nasa is abandoning economical space travel to pursue the vision." This is a false assertion based on the bias of the author of the article. Nasa is doing what government and industry most often do, and pursuing "safer" technologies. The risk is, you spend $4b on a space elivator and have nothing to show at the end. The structure is theoretical, so whether it might work or not is a theory and nothing more. There are a lot of unknowns and ther eis a lot of risk. You spend that same $4b on improving efficiency of existing technologies or developing new derivatives, and you have many fewer unknowns and a much lower level of risk. Risk drives spending. If you have a risky venture, then try a venture capitalist -- they make their money by taking good risks. So far as the DoD goes, Nasa's current approach to economical space travel -- i.e. improve the economy of existing infrastructures, build new derivatives that work with existing infrastructures -- fits much more with their specific needs. It's not just about getting the spy satalite into space for them. They need to minimize the number of people with exposure to it, they need to minimize its presence on civilian structures. Something that they can launch from an airforce base off of a conventional landing field fits those needs much more than a needle would. It's not just the matter of moving the cargo to the needle, it's the matter of minimizing contact of the cargo with non-military personnel and launching it from as close to its point of origin as possible. Economy isn't the primary concern here, physical security of the payload is. For this reason, I couldn't see them taking this project on in any way that would benefit civilians or industry. If they built such a thing, I would think that they would keep it to themselves. After all, you don't see other pieces of the military infrastructure being routinely used for civilian use. For example, I live near Write Paterson Airforce Base. When I flew to Australia, I flew out of an airport 30 minutes farther away from Write Parterson Airforce Base, because obviously the airforce base doesn't want me using their infrastructure -- their infrastructure is solely for their use. If they became involved in a project of this sort, I couldn't see them opening it's infrastructure to anyone else, which would destroy the value of the project for the intended use in the article.
If your code is acting bloated, and is running rather slow, it's likely and predicted that some loops you will unroll.
So what happens when someone manages to set off a charge at the top? I don't particularly fancy having thousands of kilometers of cable wrapping around the equator a couple of times at high speed.
The space elevator project cannot and should be built at all in this world, although it's an interesting scientific/technical concept.
Think about the undeniably catastropic consequences of a structural failure of the elevator itself, either while under construction -- or even worse -- after completion.
The construction of such a project would require one of the most stringent military (!) security cordons in history. Its continued operation would require the same. (This needs to be added to the project cost, of course); and since the USA -- the only existing power in the world with the capability to even think of this -- is rather occupied with other tasks, this just ain't gonna happen.
The 'space elevator' itself would be basically the most attractive terrorist target in the entire world.
Please point me to a scientific study showing that the carbon-nanotube elevator band will withstand even ONE impact from an RPG round.
Anyone who can afford to build a freaking space elevator can afford an aircraft carrier or two to defend it.
Freedom: "I won't!"
For humans, J. Storrs-Hall (of sci.nanotech fame) proposed a space railway that could be built sooner and more cheaply than a space elevator. It's a linear induction motor laid along a 300km-long track, 100km above the ground, where the atmosphere is thin enough to take a few orbits to decay your orbit. You drive your spaceship up a ramp to one end, and the motor accelerates you along the railway at about 10G for about 90 seconds, putting you in a slightly elliptical orbit with an apogee on the other side of the Earth. When you hit apogee, you do a burn to get into a higher orbit.
Relatively little radiation because you cross the Van Allen belts much faster. You get to LEO without burning any of your own fuel, which is a big energy win. The railway is low enough that orbits still decay slowly, so there's no space junk to worry about at that altitude.
The structure is a collection of A-frames, built like a radio tower. Like the space elevator, only a tiny fraction of the height is subjected to significant weather. The structure is under compression, not tension, which widens the choice of materials. According to Storrs-Hall, existing synthetic diamond would be suitable.
WWJD for a Klondike Bar?
"This isn't the movies."
...
...
Then I guess
I took
A wrong turn, motherfucker!
Will they make the real lifter out of legos? I grew up with legos and love 'em, but c'mon! Surely, they can build a more professional looking prototype... jeez! lego lifters! hahaha
Now let go. Does the string wrap around your head?
-- MarkusQ
As early as 1895, a Russian scientist named Konstantin Tsiolkovsky suggested a fanciful "Celestial Castle" in geosynchronous Earth orbit attached to a tower on the ground, not unlike Paris's Eiffel tower. Another Russian, a Leningrad engineer by the name of Yuri Artsutanov, wrote some of the first modern ideas about space elevators in 1960. Published as a non-technical story in Pravda, his story never caught the attention of the West. Science magazine ran a short article in 1966 by John Isaacs, an American oceanographer, about a pair of whisker-thin wires extending to a geostationary satellite. The article ran basically unnoticed. The concept finally came to the attention of the space flight engineering community through a technical paper written in 1975 by Jerome Pearson of the Air Force Research Laboratory. This paper was the inspiration for Clarke's novel.
Why would anyone engrave "Elbereth"?
You seem to be making the assumption that the break occurs at the base of the elevator. I made no such assumption. Sever the elevator at any point along the length of it and the bit that's above the sever point flings out, and the bit that is below it falls. The scenario you describe only occurs when the server point is right at the very bottom.
And your analogy is terrible. The string provides the centripital force to hold the ball in a circle and thus when cut the centripital force is gone. An object in geosynchronous orbit, such as a space elevator, does not get its centripital force via the elevator's tension. It gets it via gravity - a force that doesn't go away when you cut the elevator.
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
Hey. You do it in order to scare the monsters.
But. You knew that. What surprises me is that a stone
deaf self taught man from Russia has dreams that would boggle a tech savvy person from (oh it is) the
21st century. Just like that Indian mathmagician he
*scares* me. But I love it when it reminds me how
dumb I am. (cough) MS does this every day but it's
not the same. Let's play global thermonuclear war (big grin). Or even (chuckles) drink some tea.
Since the tether point is not going to move, you can save a few billion by having a similarly immobile "aircraft carrier", if not an island then something like an oil rig.
You are of course correct: I had an order of magnitude mistake in recall, thinking about a transition from 20 to 200 tons after buildup, instead of 1,2 tons to 20 tons buildup.
"Just once, I'd like to meet an alien menace that wasn't immune to bullets." -- The Brigadier, Dr. Who
Yes, but the very, very bottom is the most sensitive part of the whole thing. That's where your cable is skinniest, and since it's the only piece that's in the atmosphere it might well be the most finicky bit to build. (Go ahead--try to catch a 40,000 km long cable dropped from space, while the teeny tiny end is blowing about in the atmosphere.)
The whole cable will also be under significant tension; otherwise you wouldn't be able to lift anything on it. (Your crawler would just drag the station at the top down, instead.) Cut the cable near the base, and the rest of the elevator starts heading for a higher orbit.
Releasing that tension would probably also make a mess of the rest of the cable. Think--you have a cable that's under five or ten tons of tension. Suddenly sever one end. There will be an immediate and rapid contraction starting at the cut end, and propagating up the cable. I can see all kinds of nasty harmonics being set up; it's an engineering nightmare, and it might result in damage--if not outright failure--at points far distant from the base.
~Idarubicin
The bulk of it burns up on re-entry into the atmosphere.
I'd be more worried about terrorists going for the platform itself. If there's nothing to tie the end of the ribbon down to, you're in trouble. There may be possibilities for temporary anchors though -I just don't know.
rolf :o)
> I don't particularly fancy having thousands of kilometers of cable wrapping around the equator a couple of times at high speed.
Good thing that's not going to happen. Do you realize howlong the circumference of the Earth REALLY is? The space elevator's length, assuming that it was actually physically possible for it to come down in one full strand, would not go around even once. It would be darn close (on the planetary scale), but still a few thousand km short.
You're drunk if you think that the sort of people responsible for 9/11 draw a very clear distinction between the governments and private individuals of the US -- or any western nation.
A space elevator would be a lousy weapon. Namely, because it is an incredibly easy target. Perhaps in peacetime the military would use it to launch satellites, but the idea that people are going to rely on space elevators in wartime is kinda crazy. It's hard to think of a target much easier to sever than stressed-almost-to-the-point-of-breaking paper-thin object which you can access either from outside geosync, at geosync, below geosync, in a suborbital trajectory, in the atmosphere, on the surface, or - in the case of Liftport's design - from underwater.
Weapons are not the only things that matter in warfare. Sabotaging your opponent's economy may affect either their ability or will to fight.
If a space elevator is build, and its traffic becomes a significant part of some nations bottom line, it will be a potential target of someone.
So no, it will not (as you claimed) "wrap itself *around* the equator"--there will be some near the ground that will fall to the ground, but the vast majority if it will not.
-- MarkusQ
P.S. I do agree with your criticism that my analogy is invalid if pushed much beyond the the point to which I took it. In general, I try to stay away from analogies that let you into error if you step off of the narrow path for which they were constructed, and had already begun to regret that one prior to your posting.
OK, so just how dangerous is 700 tons of material falling from geosync orbit?
Geosync orbital speed is 3,066 m/s.
Equatorial surface speed is 464 m/s.
Orbital Energy(J) is 1/2 * mass(kg) * velocity(m/s)^2
1 Short Ton = 907.185 kg
The energy released when 99% of the 700 short ton elevator falls from geosync is roughly 2.9 TeraJoules (2.9e12 Joules), or about 0.7 Kilotons. For comparison, the Hiroshima bomb was about 14 Kilotons.
So this thing releases a *lot* of energy when it falls, but an order of magnitude less than a smallish atomic bomb.
The next question is over what period of time is this energy released over how large an area? The claim is the object will "burn up" in the atmosphere. I don't remember enough to calculate how fast the ribbon will fall or how fast its energy will dissapate in the atmosphere.
I surmise the disappation is a few seconds (the ribbon is probably travelling a couple km/sec when it "enters" the atmosphere if we assume its speed is similar to the difference in orbital velocities). The area is roughly 1m x earth circumference, or 40 million m^2. If the energy is disappated over about 10 seconds over this area, that's about 7000 Watts/m^2, or about 5 times the amount of mean solar energy received by the earth.
From these estimates, I think it will be a spectactuar event. Probably, very bright and causing local meterologic effects; but unlikely to be spectacularly destructive -- in line with LiftPort's and others' claims.
I wish one of the elevator advocates would actually publish a more detailed analysis, showing their figures and assumptions instead of the hand-waving "it'll burn up in the atmosphere" claim.
Do you realize howlong the circumference of the Earth REALLY is? The space elevator's length, assuming that it was actually physically possible for it to come down in one full strand, would not go around even once.
Earth's equator is +- 40,000 km. Geosynchronous orbit is +- 36,000 km. However, that's where the center of mass of the elevator will be. It will have to be quite a bit longer than that. Let's look at simplistically and simply make it double as long, then the ribbon would be easily long enough.
Of course it won't all fall down, and it may be shorter and tethered to something large (like an asteroid) although it's probably easier just to make the ribbon longer, since then you can launch stuff away from Earth by letting it go from the tail end.
I believe posters are recognized by their sig. So I made one.
> I wish one of the elevator advocates would actually publish a more detailed analysis, showing their figures and assumptions instead of the hand-waving "it'll burn up in the atmosphere" claim.
l (online for several years, cited here frequently):
/ br eaks/index.html
And I wish I could hang on Slashdot and have all my answers spoon-fed, instead of tiring myself out with a few minutes on Google. But hey, we all need our dreams.
For starters, from http://www.isr.us/Downloads/niac_pdf/contents.htm
"If a cable is severed the lower segment will fall back to Earth while the upper portion floats outward. The worst case would be if the countermass breaks off the far end of the cable and the entire 91,000 km of cable falls back to Earth.
"Depending on the location of the break, the epoxy used, the dynamics of the fall, etc. the cable will re-enter the Earth's atmosphere at a velocity sufficient to heat the cable above several hundred degrees Celsius (figure 10.9.1). If the cable is designed properly, the epoxy in the cable composite will disintegrate at this temperature. This means the cable above a certain point will re-enter Earth's atmosphere in small segments or carbon nanotube / epoxy dust. About 3000 kg of 2 square millimeter crosssection cable (20 ton capacity) may fall to Earth intact and east of the anchor. Detailed simulations will be required to determine the possible sizes of segments that will survive and the health risks associated with carbon nanotube and epoxy dust. In terms of the mass of dust and debris that will be deposited, we can compare what will happen to what naturally happens now. Each year 10,000 tons of dust accrete onto Earth from space, the additional 750 tons of the first cable will increase that year's infall by 7.5%. A larger 1000-ton capacity cable would have a mass of 30,000 tons or roughly equivalent to 3 years of normal global dust accretion. Further investigations are required to determine the environmental impact of depositing this much dust along the Earth's equator."
The online version was expanded into 2002's "The Space Elevator" (try Amazon, revised edition now in the works)
For some detail on dynamics of breaks at various altitudes:
http://www.mit.edu/people/gassend/spaceelevator
Bottom line: please sketch a scenario in which ~100,000 km of ribbon all hits the atmosphere in ten seconds? You are not allowed to crank up _g_.
IOW, try getting within 3-5 orders of magnitude yourself before accusing others of hand-waving...
Fair enough on most of the points. I wouldn't go so far as to say you get shot down. At least give em a warning. But good counters
First it tries to assert that most of the cable mass won't re-enter the atmosphere. This might be the most likely case -- a meterological, accidental or intentional attack severing the cable within the atmosphere does mean only a small mass returns to earth; but the worst case is a break near the outer end of the cable, losing the counterweight (maybe 5% of the total mass) and the remaining 95% of the mass returns to earth because the new center of mass is below a stable orbit point.
Claiming the cable "disintegrates" is nice, but doesn't address the issue. It doesn't matter if the total mass is less than the amount of dust captured by the earth each year. Ask how much energy is released in the disintegration. Disintegration is not benign. If too much energy is released too quickly in too small a space you will have some serious conseqeunces.
The animations are sweet, thanks for pointing me to em. But they don't quite answer my question: how much energy is released, how quickly, over how large an area? Perhaps I'll find time to download his admittedly disarrayed code and see if I can enhance it to calculate energy release over time and volume in the atmospheric entry, but I suspect I don't have the physics knowledge to do that right.
I readily admit my calculations were back of the envelope. But at least they're addressing the issue the elevator proponents are glossing over: energy release! My orbital energy calculations say the proposed elevator is going to potentially release nearly a kiloton of energy in the worst case scenario. Very large, sudden energy release events are *bad*. Especially when they happen near people and their homes.
As to my being too lazy to do some quick research -- try again. I didn't find the animations, but I certainly knew of your primary study reference and find it unconvincing in this regard. When calculating the kinetic energy release, I did used google to find the radius of geosync and the earth surface, and to look up a Joules to Kiloton conversion so as to cast the energy result in terms of large explosive events people are somewhat familiar with for context. I'll aplogize for not being a physicist nor an atmospheric modeler, and being pretty darn rusty at orbital dynamics. But those are specialities I would expect the elevator builders to have and employ to properly study feasibility and safety concerns about this project.
I'm not objecting to the idea of building a space elevator at all. I've been interested in the concept since before Clarke and Sheffield popularized it in their 1979 novels. I'd just like it done with real science and engineering so it works and make sense and strikes a reasonable balance between risk and benefit.
You are assuming accidental failures. I am not. Deliberate sabotage can be carried out by a spaceship or by a bomb in the cargo going up the elevator, and a deliberate saboteur would go for the most damage by severing higher up the chain.
As far as burning on re-entry - to be strong enough this thing will be very massive. It will burn, but will it burn all the way through? What kind of materials do we have that are strong enough to handle the tensions this thing will be under, and yet still skinny enough to 100% burn into gasses on re-entry?
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
Also, one type of accidental failure is a malfunction partway up the ladder while carrying a load up. If a part of the ladder is getting weak, this could happen. The assumption that the only kinds of stress on the structure to be worth worrying about are the environmental ones at the base is a rather dangerous presumption.
I do like the idea of trying to make it out of something that will burn into gasses on re-entry, but I'm having a hard time imagining it being strong enough to be a space ladder, and yet skinny enough to not have any remaining mass in the core of it survive the burn. (i.e. how large do meteors typically have to start out in order for enough to survive re-entry to hit the ground?) If worst comes to worst I suppose it could be rigged with a mechnamism to deliberately separate it into smaller bits when it starts hitting re-entry (i.e. fasteners designed to melt easily).
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
> If too much energy is released too quickly in too small a space you will have some serious conseqeunces.
True-- but what does that have to do with broken space elevators? There is NO physically reasonable scenario in which all or most of the ribbon encounters the atmosphere EITHER in a small space OR in a short time. No matter how you model it, the encounter is stretched over tens of thousands of miles and at least a few hours, more likely several days. So with all due respect, I find your joules to kilotons conversion meaningless -- because the latter is a unit exclusively used for very sudden, very local processes.
I'm in the middle of a multi-MEGATON event right now -- but since it's otherwise known as a sunny September day in southeast Pennsylvania, I'm staying pretty calm about it.
I agree that there's plenty of "real science and engineering" to be done yet. But I'd be a lot more worried about, say, a 20-ton climber+payload that somehow falls off the ribbon at a worst-case altitude than about the ribbon itself.
Really? What do you base that on? I just watched the animation again. In this model, about 25% of the fastest moving end of the cable breaks off and a away, the rest falls. The last 5-10% of the cable slaps the earth in a couple of the final frames. So what are the energy dynamics?
Is it inconceivable that that last 5% of the ribbon length carries 30-50% of the entire kinetic energy of the system? So how bad is a terajoule released over a million square meters for 10 minutes? It's about 2000 Watts/m^2. Probably nothing to worry about. About twice the mean solar intercept for the area in question for 10 minutes.
"I'm in the middle of a multi-MEGATON event right now -- but since it's otherwise known as a sunny September day"
Righto. Please notice I'm actually using the solar intercept energy as a comparison point. Remember your multi-MEGATON event is spread over a much vaster area (the hemispherical area of the planet surface) then a one meter by 1000km ribbon impact.
Even so, that solar energy, at lower density, fuels large atmospheric effects (hurricanes, tornados) known to produce substantial destructive effects on human habitation :) I want to see some atmospheric modeling. Does the cable fall and disintegration seed the largest storm system we've ever seen? Not unimaginable.
Further, what happens 15 years later when we have not the one, but dozens, or hundreds of elevators, including "heavy lifters" weighing in at 70,000 tons instead of 700 tons? Will the catistrophic fall of one ribbon, sweep down 20-50% of the others? They're all placed in a very tight equatorial band.
First, the bottom (meaning lower 150 km or so) will still be much easier for saboteurs to reach, and therefore the more likely target.
Second, it can't be something "massive/thick" as you are assuming, since it wouldn't be able to support its own weight. It will be more like a very strong carbon fibre ribbon than a mondo steel cable. And carbon (a.k.a diamond, bucky tubes, etc.) burns very well. Strength, in this case, prety much implies easy-to-burn.
-- MarkusQ
-IF- the elevator's ribbon was severed at GEO in a worst case scenario, two things would happen: Some of the ribbon would flutter down and make a long trail of cooperative ribbon to clean up (it would be like a super-strong trail of newsprint, essentially) or The upper ~30,000km would gain enough velocity to burn up in the atmosphere. Even if the whole thing did come down, it wouldn't break anything, we'd just have to cut it into sections and roll it up.
> The last 5-10% of the cable slaps the earth in a couple of the final frames. So what are the energy dynamics?
Just work the magnitudes of your own words: "the last 5-10% of the cable" is roughly 40 to 80 tons, stretched over roughly 5000 to 10000 kilometers. Were there big weather effects when the ~45-ton Skylab or the ~120-ton Columbia burned and disintegrated within a much smaller zone of the atmosphere? A falling SE cable would be moving faster, but not *that* much faster.
I agree that the "fratricide" issue (also discussed at Blaise Gassend's MIT pages) needs more analysis, and that much more massive SE cables *would* make a worst-case catastrophic failure a real concern. There'll be a trade-off somewhere between "more" and "bigger."
-Monte
I'll believe in this super-strong ribbon when I see things being built with it.
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
>>Except if the cable breaks and wraps around the planet 3 times!
>1) it's not that long
Well, it is, almost: Earth's circumference is about 25k miles, and a space elevator would extend out to 62k or so, according to LiftPort.
But the point is there's no danger from such a system breaking and falling. The ribbon will be remarkably flimsy as far as doom-from-the-sky things go, and will just shred into little pieces.
- Peter
INsigNIFICANT
This is from a colleague at a well-known public university: AIR FORCE ACADEMY TEAMS WITH LIFTPORT FOR CADET-LEVEL SPACE ELEVATOR RESEARCH Senior-level US Air Force Academy cadets are performing independent astronautics studies with LiftPort Group to conduct research on the first commercial space elevator, which could ultimately send cargo--and perhaps humans--into space. The Bremerton, Washington firm will provide the academy with a list of proposed research topics on the space elevator, and cadets can select the topic of their choice for end-of-semester papers. Throughout the course, LiftPort is offering cadets assistance in accessing the latest resources on the space elevator concept, from interviews with leading industry experts to access to the latest studies. "My students are fascinated with the concept of the space elevator," said Major Tom Joslyn, USAFA instructor of astronautical engineering and mentor for cadets conducting space elevator research. "They are young enough to see such a program come to fruition and many of them see it as a next generation launch system that could revolutionize access to space."
Well, I will concede this point. But the economic impact of the destruction of the ladder must still be seriously considered. Given how much it will take to build this thing, even if it is destroyed in such a fashion that nobody gets hurt, it is still very devastating to have the world's biggest project, constituting a signifigant percentage of the GNP, get flung away.
The ladder will not be practical when it is first buildable. It will be practical when the means to build it is cheap enough that it can be replaced with ease.
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
That's still bad science. Are they going to change the theories of the fabric that makes up space to allow their equipment to stay lofted? Two stationary objects in space will move towards each other dispite their distance from each other. Their is not distance in witch the object in space, away from earth, will not have a decaying orbit, unless it is influenced by a larger body, such as Jupiter or the Sun. Facts!