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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.
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.
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.
I dare you to drop a penny off of the top.
Queue, the correction hordes...
The grass is only greener, if you don't take care of your own lawn.
No you can't, you can't stay in the Van Allen radiation belt for a long time, as it would be necessary in a space elevator. For more info have a look at Wikipedia - Van Allen radiation belt .
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!
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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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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.
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.
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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
A space elevator will be a cheap-to-operate lifter once it's in place, and it'll have the nice advantage of being able to take items FROM space as well.
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.
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This problem can be conquored with adequate shielding- and thus isn't really a problem.
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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?
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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!"
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...
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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.
Tell that to the victims of the previous attempt at a space elevator. That is what everybody is imagining.
Seems to me that every piece of modern technology we have was at one point considered scientific fantasy with countless people declaring that it would never work. Space flight, cell phones, computers, telephones, airplanes, electricity, radio, recorded sound. Every single one of them had problems that could 'never be solved'. And guess what? They were solved.
If you had been at Kitty Hawk, you would have been yelling that the glider would never fly. And as it passed over your head, you would start claiming that they would never get it down.
Technoli
"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
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
...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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Or, y'know, a small island. Assuming they can find a small island in the middle of the ocean.
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?
Wait a minute. You think shipping goods an extra few hundred kilometers via container ship is somehow economically prohibitive? It's obscenely inexpensive and easy to ship goods by sea. It's the getting it to space part that's tricky.
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.
Of course it creates its own problems. Namely, that we'd need to restrict air and sea traffic in a certain area, we'd need to find a suitable island for the project, and we'd need to create a special shipping lane for spacebound cargo. You seem to view these problems as showstoppers; I don't really see anything prohibitively challenging about the examples you cite.
When will you people get it through your heads that space elevators won't work?
Probably never. Then again, odds are I'm too dense to see the nuanced wisdom in your above statements, and my responses are all hideously naive.
Obliteracy: Words with explosions
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
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.
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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
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.
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.
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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?
And then watch it go sideways.
Real Daleks don't climb stairs - they level the building.
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.