Slashdot Mirror

See the Space Elevator Reference story for more information on this hyped story.

Crash it on the moon instead, then mine the heck out of it. Or else orbit it around the moon and push the ore back to Earth.

Realistically, though, this stuff is going to need a space elevator to economically get the ore back down to Earth.

I used to believe those nations who control the skies will be the top powers, but now I think more likely it's those nations or corporations that control the ladders up to the skies that will really hold all the cards.

Anyone interested in this issue should read the NIAC report http://www.spaceelevator.com/docs/521Edwards.pdf which discusses the issues in detail and the technical problems. Space elevators would make space travel much cheaper. But the technical issues are immense. The NIAC report carefully outlines the major issues and how they might be handled. We would need to make extremely high quality carbon nanotubes at an immense scale. We also would need to put into space a structure orders of magnitude larger than anything we've put in space. Indeed, a space elevator would be one of the largest physical structures ever made by humans. And the engineering hurdles, such as the problems of wind in the lower atmosphere, are massive. But there's nothing about the idea that is physically impossible. The primary issues are issues of scale. And the issues are being worked on. Right now, there's a lot of work on making carbon nanotubes of high quality in a large scale. Since such nanotubes would have many different applications there's a lot of funding for that and that will likely be extremely beneficial to humanity well before it scales up to anything near that needed for a space elevator. Since the nanotube manufacturing is the primary technical hurdle, this is a good thing. I doubt we will see a space elevator in my lifetime, but maybe my children, or their children, will see it. And on that thing ribbon, space travel will finally become as cheap as so many have envisioned it.

Space Elevator. Now. .... I honestly don't know why there isn't a lot more effort in this direction already.

Dammit, I can't believe this keeps coming up. Because it DOES NOT EXIST! It's a science fiction fantasy. Will never work without massive leaps in technology that no one knows even how to approach solving. Might as well research magic at this point.

That's an unfair characterization. The technological hurdles are large but they are well-understood. There's an excellent 2002 report by NASA's Institute for Advanced Concepts http://www.spaceelevator.com/docs/521Edwards.pdf which discusses the technical problems in great detail. The primary issues preventing a space elevator are related to the tensile strength of the ribbon/line. Carbon nanotubes are in theory strong enough, but they need to be able to be manufactured at a much larger scale, with higher quality (especially in regards to average tube length) and need to be placed in a reliable matrix. The reason that it looks like there isn't much space elevator research is really because there's very little that would need to be researched that specifically about space elevators. The primary issue is carbon nanotube research and that's happening now at a quick pace because carbon nanotubes have lots of different applications. The technologies necessary for a space elevator are already being developed for other applications.

You don't build a straight cable, rather a tapered one (which is where I get the bubble gum comment). The current guys are shooting for ~8x increase in strength over today's strongest materials. That is due (largely, IIRC) to limitations in current lift systems (i.e. chemical) and maintenance requirements.

If we deployed gas core nuclear lift, everything changes.

Orion was a fascinating concept, but the approach isn't scalable on a very important axis -- number of flights per year. Sure, you could launch a lot of payload with one launch, and that might be useful from time to time, but getting to orbit on demand at a lower cost than we can do today is more important. If we invest, at a consistent steady pace, we can build systems to reduce the cost of getting to orbit. If we invest in technologies like VASIMR, we can reduce the amount of fuel we need to haul up to LEO to get somewhere else, which has a very nice multiplier effect.

Reducing the cost of access to space will make it possible to do many things, great, interesting, useful, economically beneficial, and fun. Rather than a few trips to the Moon a year, and a trip to Mars once or twice, and then nothing for fifty years, we could have ongoing routine exploration, manned and unmanned, expanding our reach, for the same price. Focused and continued R&D is the key. We have come tantalizingly close to setting the right, attainable goals, and nearly reaching them, with the X-33, VentureStar project, which sought to develop a set of specific technologies in such a way that the end result would be a transportation system. Had we stuck with it, we would have it by now, at a cost which would have appeared to be modest by STS standards. More importantly, it would liberate substantial sums which are currently hostage to the operational budget of the STS. Other technology approaches to similar cost-per-kilo performance and reduced operational cost are possible, such as Skylon. Unfortunately, the Orion / Aries approach is not designed to meet these goals, and will never achieve meaningful increases in flight rates.

Even tiny sums of investment and tiny prizes have stimulated technologies like electromagnetic rail launch (pioneered with a grass roots donation campaign, which funded research spanning decades, by the Space Studies Institute) and tether climbers for space elevators. Even a well-funded, focused R&D effort might not bring an Earth to orbit space elevator for a long time, but without the effort it will certainly take longer. A fascinating intermediate step would be a space elevator from the lunar surface to lunar orbit. No atmosphere or weather to contend with, shorter elevator system and smaller gravity well. The payoff would be dramatic reductions in fuel mass required to sustain a base on the lunar surface -- a huge multiplier effect.

Spending on research like this takes place on Earth. The benefits would be substantial. Now is the right time to start.

Missed the bit where you couldn't use Google or Wikipedia.

Here's a paper looking at the economics and compares it to current rocket programs: http://www.spaceelevator.com/docs/iac-2004/iac-04-iaa.3.8.3.09.raitt.pdf

Here's one of the most comprehensive proposals: http://www.spaceelevator.com/docs/472Edwards.pdf

Note that they propose using a small cable and shooting climbers up it, which them reel themselves out and become the counterweight. You also lift additional strands of cable to strengthen it, so you can lift more. The initial material that needs to be lifted by rocket is quite small -- everything else is bootstrapped up the cable itself.

Missed the bit where you couldn't use Google or Wikipedia.

Here's a paper looking at the economics and compares it to current rocket programs: http://www.spaceelevator.com/docs/iac-2004/iac-04-iaa.3.8.3.09.raitt.pdf

Here's one of the most comprehensive proposals: http://www.spaceelevator.com/docs/472Edwards.pdf

Note that they propose using a small cable and shooting climbers up it, which them reel themselves out and become the counterweight. You also lift additional strands of cable to strengthen it, so you can lift more. The initial material that needs to be lifted by rocket is quite small -- everything else is bootstrapped up the cable itself.

Corrode? How?

Atmospheric effects (oxygen I assume among other things), random effects, micro-meteorites and so on. And of course the climber has to do just that CLIMB the thing, that constant contact will likely cause damage over long periods of time.

This is something effectively the same as sheets of graphite in the high strength direction which is going to be in contact with the same material in a vaccum. Also by breaking - by what mechanism? Wouldn't the design be such as to spread the load to somehting the fibres can take.

Nothing is perfect or indestructible.

I think you'll also find that the joining you describe is about bundling the fibres axially and not sticking bits on the end of individual fibres longitudinally otherwise you would lose an order of magnitude or two of strength.

No right now it's about using short fibers as we have no foreseeable technology to make massively long fibers. Pretty much short of specialized advanced nanomachines there is no sane way to make something that long, random problems will crop up and cause breaks or problems in every fiber before it gets even close to that long. The original designs involved using actual epoxy and apparently calculation still gave the result enough strength. Also current design have a tapering cable that is much thinner at the bottom than the top.

Please explain the theory of high temperature superconductivity that shows it is not possible - all the theories I know are empirical and actually pretty confusing.

As I said some theories, in other words someone claims it is not possible. Given current problems and the complexities of the best superconductors it may be the truth.

he MBAs I am talking about are the ones that are running the space elevator consortium which is not linked with NASA since NASA is doing other stuff.

The current power beaming competition is being funded by NASA, partially at least. There are a number of scientists/engineers in the group although the group isn't there to do research. Some of the research done for this can be found here:
http://www.spaceelevator.com/docs/

I really have no idea why people for some inane reason always claim others, despite being more qualified, are wrong while they, and their pet theories, are right WITHOUT even looking up the explanation for something. If you disagree with them you could have emailed them for justification, could have looked at the literature in the area, could have contacted people involved in the project and probably other bloody things. Let me be blunt, you're an atrocious debater, if you wish to claim that something is wrong then you need to do it in a LOGICAL fashion. That means you find out why something is done a certain way then rip it apart. If you don't know why someone is doing something one way how in god's name can you claim their reasoning is wrong? Instead you take up others time on slashdot, a place where pretty much no one is even close to qualified to discuss this subject.

The space elevator is amazingly thin first of all, millimeter thin at the bottom possibly and only meters wide. It is absurdly long, 35000km, and all energy need to be provided ground side for now. Each climber may require say 500watts of power for a 12day ascent which means you need to be supplying say 10MW to all the climbers at any given time (this is the energy they need to receive after all loses are taken into account, you need to send much much more). Carbon nanotubes aren't that amazingly conductive, an order of magnitude close to copper over long distances I believe. Graphite is for example a few orders worse than copper in that department I think. My quick calculation put the energy loss at over 50% easily (as in even when I'm being conservative) and I'd say it's way over 90% even in the mid point if you were to properly calculate it (with realistic values and considerations).

Well, just saw this

EuroSpaceward was just awarded funding by The National Research Fund of Luxembourg to hold a workshop on space elevator climber and tether design primarily focusing on systems for entry in the US and German competitions. The tentative dates are Nov. 14-16, 2007 and the workshop will be held in a yet to be announced venue in Luxembourg.

found at http://www.spaceelevator.com/

So it does seem there is still some interest outside US, albeit for entering a NASA based competition. I think that the immigration problems in the US for foreign students will quickly have some negative effect on innovation in the US in the long term. Innovation in the US has always been due to it's courting of students world wide to study and then contribute.

Perhaps EuroSpaceward is luckier. They're holding a workshop in November.

I have been following this for some time... Here are a few links for ya.
http://www.isr.us/Downloads/niac_pdf/contents.html Study
LiftPort Group. Company wants to beat NASA.
Reference Site



Place a curse on the RIAA/MPAA

You are right in saying that this is not enough energy to maintain an orbit. According to spaceelevator.com You would come off the cable at 3.1 km/sec and would need a booster to bring you up to enough speed to maintain Low Earth Orbit at 7.7km/sec.

But you saved on the lower stage and you don't have to worry about atmosphere anymore, so it would be a good Shuttle replacement. Even now when a sattelite is released from the shuttle, a booster is required if you want to get it to a higher orbit. On the other hand if the elevator is ever built low Earth orbit will probably not be used that much anymore. It may in fact be dangerous to have things that may hit the cable and most things would be brought to geosynchronous orbit.

Yes, it was a serious interview. The idea of a space elevator has been bandied around in scientific and science fields for a number of years, but the strength of the cable needed to hold it up was always a sticking factor. With the discovery of Carbon-60 (Buckyballs and Buckytubes) the strength factor is theoretically within reach.
The basic idea is an elevator with its center of gravity at geosyncronous orbit, making the elevator stay in one spot over the earth. It would allow for much larger space lift capacities and much lower costs per pound.
Read more at:
Wikipedia
The Space Elevator Reference
Liftport Group, a consortium of companies working on space elevator tech
Also, for a good sci-fi treatment of space elevators, read Kim Stanley-Robinson's Red-Gree-Blue Mars Trilogy

If at all plausible from a technical standpont, space elevators are probably the most sensible way for sending humans or loads to space. If you can't beat gravity, use it. Armchair engineers can send in their entries.

Face it: from a standpoint of physics, wind, water, and solar ...

The paper the article was based on is here: (276k pdf)

The space elevator was not created by science fiction writers. It was first theorized by Soviet scientist Yuri Artsutanov. Later there we some NASA papers that expanding on the theory. You can read about it here.

If you are going to debate the con side of this issue please produce facts not emotions.

What we know is that higher income and education reduces number of children.

The question is actually how much people with income approx equal to US or that one in Europe the earth could sustain?

from my memory the estimation was about 10-15 billions people. And estimation of the population we have in hands say that earth population will not exceed 15 billions at least for coming 100 years.

as for sustaining energy for every one of 15 billions. There are alternatives see for example solar power from moon idea.

(Slashdot had an article on solar power energy report to congress last year, later I found the link to report of the author of idea see http://www.worldenergy.org/wec-geis/publications/d efault/tech_papers/17th_congress/4_1_33.asp )

Coupled with possible space elevator http://www.spaceelevator.com/ and new advances in solar panels with higher efficiency such as for example approach here http://www.lbl.gov/Science-Articles/Archive/MSD-fu ll-spectrum-solar-cell.html the paper http://www.lbl.gov/Science-Articles/Archive/assets /images/2004/Mar-24/Multiband%20Semiconductor.pdf it will cost to develop even less than estimated in original suggestion and thus cost of power will be even less.

also even though we are far from fusion power - but nuclear power on fast neutrons ( as we call it here in Russia not sure what is the proper call for the approach in English) ( so not that well known nuclear power stations on slow neutrons but that power stations based on new approaches with greater efficiency) could provide energy for the earth ( with the already known resources of uranium) for 2500 years! ) to reduce nuclear pollution it is possible to use such things as http://www.anlw.anl.gov/htdocs/anlw_history/reacto rs/ifr.html with recycling of nuclear waster.

That is - I think that rather than try to control growth of population it is better to devise and pursue clean ways to get power and provide better living standards for everybody - then there will be less pollution and the growth of population will stop.

Van Allen comments that 'the only surviving motivation for continuing human spaceflight is the ideology of adventure.'

Good enough for me.

Of course, last I checked, that's where this comes into play.... which pretty much invalidates his entire argument... As well, achieving something like this would put a few more nails in the coffin housing this guys argument.

In short, he's right... for now, but if these things come to pass he'll be as full of shit as this guy was when he said this (beware pop-ups if you aren't using Firefox)

>> Is there really a future for "horizontal launches of reusable spacecraft"?

Not if the space elevator is built in the next ten to twenty years. All that's needed right now is a good way to bond carbon nanotubes.

If you really want to make the USA into a Space Faring Nation again, we should put our money into space elevators.

In just 2 decades, this idea has gone from being impossible to far-out to design studies.

By comparison, the ISS is a waste and the Moon would be an expensive diversion. Space elevators would really open the solar system up for human - not just robot - exploration.

Sorry, forgot the link...
A nice explanation

I haven't seen any good ideas for something that will cheaply [make it above LEO].

Disregarding speed for a moment I think the most affordable way of getting mass into orbit may just be the Space Elevator

The science I'm most interested in is that which allows man to -stay- in space. (i.e. self-sustaining space environments, or nearly self-sustaining)

This is of the utmost importance, agreed.

Bush's Mars mission is more likely to approach this goal than any non-manned science mission, and as such I believe it to be a better use of funds.

Here's where I disagree. Bush's proposal as it stands doesn't have a snowball's chance in hell to succeed, but for the sake of argument let's assume it does, and that in, say, 15 years men stand on mars, at a cost of, say, $100B. Now that'd be a great achievement, but it still has a fatal flaw:

To send the *second* crew to mars will cost less, but not all that much less - let's say, $10B. To send the third, fourth, etc. crew will still cost $10B each, because of the high launch costs. Once everyone has gone home again, what you'll be left with is an American flag and another deserted "memorial station" or two standing on an empty world. This is precisely what happened to Apollo.

It's all down to economics: reduce launch costs by a factor of 10, and space exploration will thrive. Reduce them by a factor of 100, and space commerce (mining the moon etc.) will thrive. Reduce them by a factor of 1000, and space tourism will thrive. All by itself, without any need for "presidential visions" beyond giving NASA the one priority that should override all others: reduce the cost of getting us out of our gravity well. By itself it ain't sexy, but all else will follow from it.

But let's face it: sitting atop a giant barrel of explosives is *never* going to be cheap enough nor safe enough to let this happen. The shuttle was supposed to reduce launch costs (by being reusable), instead it increased them (by having to be *safely* reusable). The only technology I know of that may be capable of getting us into space cheaply is the space elevator. I would gladly forgo all other space projects for 20 years if the funds and effort went into building the first space elevator, because I know that once it's built, we could catch up with what we missed in no time flat, and then spread "up and out" for good.

- nic

Actually, if the current administration was serious about making space more accessible, while not build a space elevator. According to one study the cost is $10 billion and it takes 15 years to build it. More economical than a traditional trip to the moon, which cost was estimated to be closer to $400 billion by the previous Bush'es administration.

Although I admit, this is some cool ass shit, it's slower than watching paint dry. Of course with millions invested, they have to make sure they don't f*ck up, like some of the other doomed mars missions in the past (including the one where software "glitches" caused it to become like a bug on the grill of a speeding big rig; must've been an ex-M$ programmer who made the boo-boo). Or it could be the ol' adage of the $300 hammer and the $600 toilet seat comes to play.

Now, wait until the guys who brought us Robot Wars and Battle Bots do Mars Exploration....rovers that seek other rovers all while exploring. Of course, not until cheaper reusable rockets or an alternate method, it would be a bit hard for normal folk (aka the non-million/billionaires).

I think you need to have a look at Liftwatch. There are a lot of announcements such as these. There are nanotube advancements almost every month, and a whole bunch of universities and corporations worldwide are throwing rather large sums at putting it under heavy research. A 1km cable with 2% CN loading was already constructed a while ago. Smaller stretches were already made with 5% loading at the time the NIAC phase II was written, and was mentioned in said paper.

You neither need to grow a 35000km buckytube, nor do you need to reach a 100% CN-loaded ribbon.
Composites will be made with a higher and higher CN loading, and once a certain percentage is reached (feel free to check the NIAC 2 paper which draws this line quite clearly), you'll have elevator-worthy material. At the rate CN loading in composites has been increasing in the past decade or so, we should [hopefully] have elevator-worthy material in about 2 years.

Cheers.

It's called the Space Elevator. Problem is that it would take a mindboggling amount of capital expenditure (with no guarantees of success) before you launch your first load. After that, it's essentially free. Like anything else in the space business, that first step's a killer.

And of course it isn't rocket science. That's the whole point.

Let's see:

1986: NASA loses ability to put men in LEO following Challenger disaster
1989, Bush senior: let's put men on Mars!
2003: NASA loses ability to put men in LEO following Columbia disaster
2004, Bush junior: let's put men on Mars!

Diagnosis:

1. severe reality disconnect
2. inability to learn from experience
3. stuck in a "Groundhog Day"-type loop
4. possible violation of the ban on human cloning
5. reelection more important than future of humanity

If Bush wants space exploration instead of white elephants, he should fund more robotic probes. If he wants to be seen as a visionary, he should fund the space elevator, which would do more for manned spaceflight than any number of economically unsupportable, one-shot Apollo-type stunts. (That said, I'd take the one-shot Apollo-type stunt anytime over the ISS.) But what am I saying, I'm forgetting diagnosis #5 above.

- nic

"The administration examined a wide range of ideas, including new, reusable space shuttles and even exotic concepts such as space elevators" (my emphasis).

A space elevator, now there's a project worth pursuing. If we could only master the technology needed (superstrong materials, read Arthur C. Clarke's Fountains of Paradise or see this site for details) a space elevator would pay for itself in a matter of years and open up space for humanity like no other initiave we can even imagine today.

That aside, I wonder if we will read about this period in 30 years time like we do today about Nixon's deliberations about what to do with the Apollo program, not to mention how special interests got the Space Shuttle funding even though there was little science to gain from the program which basically tied us to LEO for decades? I wonder how much frenzied scrambling has been going on inside NASA these past few months to come up with realistic programs while the Prez is in a benign mood (all part of the re-election strategies, no doubt).

Whatever comes from this, if anything at all, let's try to make it an international effort. First of all that would be good for international cooperation in general, it wouldn't look like one country was doing this for strategic purposes and it would ease the burden somewhat for the US taxpayer. Fair is fair, the entire human race will (hopefully) benefit from this, so we should all chip in.

One good way to get from Europe to the US is to get in a row boat and start rowing.
Another is to go work someplace for a month and use the salary to buy a plane ticket.

NASA's rowing. I've taken the time to read the Space Elevator Phase II NIAC paper. For a good many years now, composite fabric with a higher and higher percentage of carbon nanotubes loading(hence a higher and higher tensile strength) is produced each year. Moreover, each year the scale of production jumps higher and in a very non-linear fasion. They were at 5% CN loading in March 2003 (as of the writing of the NIAC Phase II summary paper), promising 15% in a few months and techniques that will allow 25% and higher.
According to the current estimates, this will get us to elevator-worthy fiber in mid-2006.

If NASA really wanted to get to Europa, they'd funnel the 10 bil at CN research, building power-transmission lasers, hammering out the political hurdles and building a working elevator. Then they could send a manned boomer sub to Europa if they wanted, probbably for less money than this new idea of a white elephant.

For those too lazy to go read the paper, here's the piece that'll interest us:

"The University of Kentucky has published and patented on fibers 5 km long with 1% carbon
nanotube loading that achieved a tensile strength increase from 0.7 GPa to 1.1 GPa. Recent
results have included producing fibers with tensile strengths of 5GPa with ~5% CNT loading.
Steel has a strength of 3 GPa and Kevlar is at 3.7 GPa. This process used multi-walled carbon
nanotubes. This implies a roughly 100 GPa carbon nanotube strength or an interfacial adhesion
roughly 1/3 of theoretical. However, we must remember that in the current process only the
outer nanotubes are being functionalized and attached to, the inner tubes are not being fully
utilized. Understanding this implies that by finding a method to utilize the inner shells would
enable production of material performing close to theoretical maximum. A complimentary
technique now being developed at Rensealler Polytechnic Institute allows for the pinning of
the walls in the multi-walled tubes together so that all of the tubes can be used. Techniques at Foster
Miller will also allow for dispersion and implementation of the carbon nanotubes in the
composite at much higher loadings. Loadings over 25% have been demonstrated and higher
levels are possible. By combining these techniques the resulting material should have a tensile
strength near theory of 150 GPa for 50% loading. Material at 12 GPa (4 times stringer than
steel) is expected in the coming months and the full strength materials should be available within
two years at the current research rate."

"Hear that, NASA? That is the sound of inevitablity..."

Linky

This talks a bit about the advances in nanotubes. HiPCO is gaining a lot of headway.
If you have IEEE journal membership there are a lot of papers on it.

An article written about the idea, this year:

Space Elevators Maybe Closer To Reality Than Imagined

Much more info here:

The Space Elevator Reference

CB

I hadn't really considered the 'vested interests' argument before; but it makes sense. If the price per kilo is to come down, it'll happen because of competition from a new source; most likely private enterprise.
Already we see China, Japan and Brazil expanding their space activities, with India planning a mission to the moon. More and more companies, too, are getting in on the act; I believe the Roton was mentioned here before.
The more countries and/or companies there are involved, the more incentive there is to lower the prices to something reasonable.

Of course, if we had a space elevator, it'd be far, far cheaper. And faster. And better.