Success in 'space elevator' competition (Update 3)

That's the best thing I've seen all day. However, could anyone tell me, how would lift a cable up to 26,000 km? Surely it would be too heavy for a rocket to carry without costing zillions of dollars.

This is going to fail, the idea only looks good on paper. However, at least they might find a better way for us to design elevators for skyscrapers. That one in dubai is what, a mile high?

^nuge
The concept is to launch a satellite with a light and thin cable or ribbon which it spools down to the ground. Then a very light climber ascends the cable or ribbon and lays down another one, increasing the strength. This is done until the cable or ribbon is strong enough to support the heavy climbers.

Okay fair enough, but even a very thin ribbon will be freaking massive if its 26,000 km long.

Nanotubes cables are the way to solve at least some of these problems.

is it theoretically achievable to have a geosynchronous orbiting anchor, with cable spaning down to the ground?
I mean even if the space anchor is in geosynchronous orbit, the cable will not be. The gravitational pull on the cable will pull the orbiting anchor down, won't it?

In this scenario I'm not taking into account the air resistance of the cable, which will induce some more pulling which won't be downwards-only.

Giant lightning rods are not a good idea.

nuge is right, at 26000km a string's mass will destroy itself, not to mention effects of differing pressure, upper level winds, temperature difference, and the junkyard in low earth orbit. Carbon nanotubes are a step forward, but I don't think they even come close to the tensile strength needed for this to work. There may come a day when this IS possible with new materials, but I think the answer is in a different structure or method. Maybe Earth's gravity well is just too deep for a surface to orbit system, I don't know, but I think we can beat it somehow, someday.

Here is my solutions...feel free to patent them.

We need to mine the universe. Find a few big asteroids full of Rhodium and Platinum as well as other useful space material like deuterium. Then you can reverse the problem. It then becomes...
How do we counter weight a big ol rock falling thru space onto the earth? With a 26000km long rope with a bucket full of people and supplies on the other side. And because the cold vacuum of space, the pully shouldnt be a problem to engineering.

Or if you dont like that one...

Collect lots of fusion feedstocks, have a reactor floating around @ 26000km. Have a mega cable shooting KWH's down to earth. And the way up will just pilfering KWH's charging the on board batteries. We could have them all over the planet serving multi functions of power generation and space travel. Again, space makes fusion easier.

Carbon nanotubes are strong enough to handle this, but we are many years from a manufacturing technique to make them long enough and thick enough. There's a lot of other engineering issues to overcome with this, but I think it might happen by 2060 or so.

As for the weight of the cable, it would cost big bucks to get an optimally thin cable in orbit. But then making the cable thicker would be as cheap as driving a progressively larger car a couple hundred miles and dropping more cable down. In the long run the initial costs will be offset by cheap access to space. People smarter than me have done the math and see the concept as feasible and profitable once the technology is there for it.

The technology must be further developed. The technology of the propulsion hase a lot of potential. Only the strenght of the rope or the long wire is a problem. Surely over a larger distance then 10km. A lot research and more money hase to be invest to make it succesfull. It have great potential thats for sure!

We don't have the tech. to make the tether yet...but it is theoretically possible with some modest advances in nanotech.

This will be an interesting story in about 15-20 years....

"Cable" is a misleading term; the current designs look more like a ribbon - maximizing climbing surface while minimizing weight.

So what are the consequences of a catastrophic failure of such a space elevator - due to lightning, LEO space junk, corrosive compounds in the atmosphere, or even intentional attack? 26K Km of anything under that kind of tensile stress has got to be a big concern.

MikeKier, 26K km falling thread. How long time would it take for all of it to fall to the ground? Wouldn't it accelerate to very high speeds, since it is a thread it would have a minimum of air resistance. It would be rolled up around earth maybe? Like a giant razorblade cutting through the landscape.

Why don't you people read up on something before posting ill-informed opinions.
A lot of research has been done on this over the years.
Why not search the internet to find out why:
1: A 26km falling thread/ribbon/ whatever can be easily designed to be fall safely even if it did break. No more dangerous than any other falling lightweight ribbon.

2: The tensile stress is not a problem.

3: The whole construction could be achieved for a fraction of the cost of establishing alternative (eg chemical rocket) infrastructures for getting stuff to geosynchronous orbit...
... The list goes on.... Have fun.

Ensa has the right idea. The objections raised in this thread are almost all addressed. Liftport has a pretty good FAQ and forum all about space elevators - i suggest everyone go and read a bit of it.

The prospect of reducing costs to orbit from $10,000 / lb to $10 / lb is enough to invest heavily in this dream.

yea vlasev. That needs to be accounted for; as the "geosynchrosity", if you will, needs to be pushed farther out than it normally would be. Keep in mind, though, that the cable's apparent weight goes down (and could even turn negative) as it gets further away from earth.

Why dont they invest in something worth while like desertification or clean water.

As someone said: Bad idea.

These types of cables need to be fairly thin in order to not collapse under their own weight. But once they are set up you can't move them out of the way of hazards:

- Thunderstorms. These cables are glorified lightning rods. Carbon nanotubes are especially bad at not melting when lightning strikes them. NO place on the equator does not experience a thunderstorm every once in a while.

- Hurricanes. Wind force could cut them. If the wind doesn't do it then the debris will. Again: the equator has lots of those kinds of storms.

- Space-junk. We have gazillions of tiny, sharp and incredibly fast particles flying around in earth orbit. Not to mention all the rocky stuff the universe constantly throws at us. Notice how they move the ISS out of the way every time something gets close? Well, you can't do that with a tether.

- Terrorism. Can you say "perfect and easy target"? You could sabotage them with a ground based laser or a model airplane.

lightning rods -- not really -- like apples there are many different types of carbon nanotubes and not all of them are great conductors

They don't need to be. A thunderstorm is usually accompanied by rain. A cable (of any material) that is wet is a great attraction for lightning. Remember: all you have to have is a BETTER conductivity than air in order for lightning to choose the cable over another route. The temperatures that are created by a lightning strike are way in excess of that needed to melt a carbon nanotube cable. (Low conductivity means high resistance, which in turn means high conversion of power to heat once lighning does strike)

Another issue I just thought of:
How about the weight of ice forming at high altitudes on such cables? Apart from stopping all the nifty elevators robots it might be enough to tear the whole structure down.

lots of new advances in material surfacing for the purpose of shedding water. possibly, the tether could also be employed to "harvest" lightning as a power source and/or to contribute to the grid. also- the tether itself could be engineered to in effect be a power supply/transmission conduit to transmit, say solar power from geosynch orbiter to earth, and simultaneously power the lift vehicles. not difficult to conceptualize, and probably closer to actuality than expected-possibly even well within the 10-15 year zone.

Caliban:

lots of new advances in material surfacing for the purpose of shedding water

a) They don't leave the surface dry (not DURING a thunderstorm)
b) they make the surface slippery (which you definitely don't want since it would make your robots slip off the surface, too)

the tether could also be employed to "harvest" lightning as a power source and/or to contribute to the grid.

The energy content of a lightning strike is very low (an average bolt of lightning has enough to power a lightbulb for a year). Only the POWER of a lightning bolt (energy/time) is high.

Burning a piece of wood in your back yard every day would be a more efficient (not to say less expensive) power plant than an entire space cable used to harvest lightning strikes.

I have to say I finally registered simply to comment on this article. I used to think the idea of a space elevator was retarded, but after hearing the logic behind it the idea makes a lot more sense than conventional rockets. As for the strength needed to support the ribbon, I was always under the impression that a station floating in orbit at the end of the ribbon would act as a balloon to hold it up. And wouldn't the station also act as the caboose? Any movement from winds or such would be detected and could be immediately compensated for... But hey I only got a D in high school physics. I assume the people involved in such projects are much more intelligent and creative than myself; I have no fear of a giant ribbon slicing through my home. But what would be nice is if instead of carbon we could get something in a nice pink satin....

is it theoretically achievable to have a geosynchronous orbiting anchor, with cable spaning down to the ground?
I mean even if the space anchor is in geosynchronous orbit, the cable will not be. The gravitational pull on the cable will pull the orbiting anchor down, won't it?

No that's not a problem, its the centre of mass of the anchor and cable that is in geosynchronous orbit, not the anchor. The anchor is even further out.

By the way, in my first comment I wasn't saying that the tension on the cable is a problem, I'm sure modern materials could handle it; I was just saying that lifting a 26,000km cable into orbit would take a big effort and a lot of money because that wire would weigh many, many tonnes. As someone pointed out, the best way to overcome this would be to make the cable in orbit, and drop it down. I think whats needed is to make a space station like a big spider spinning a web. I certainly agree that most of the problems could be addressed, but achieving this would be a big challenge.

I also decided to register to comment...

Let's start by assuming that the issues the arm-chair engineers are bringing up have been thought through and there are solutions at least in the concept stage. Next, lets get out of the box and look at some great applications for a space elevator outside of Earth. Having one on the moon would be much easier than on Earth. Mars is also a good place for one. So, why would we want to build a space elevator on Mars and the moon? Because moving raw materials from Mars to the moon is cheaper than from Earth to the moon (i.e., we'll feed our moon station from Mars). What moon station? The one we build there that is sending resources back to Earth and being fed from supplies from Mars. I realize this sounds bit strange, but it's all pretty well documented. Earth is the worse case use for a space elevator, but even here it's a better long term solution than rockets.

I feel like all of the complainers are extremely lacking. First off, a thunderstorm occurs because their is a negative charge in the clouds and a relatively neutral charge on the ground. A direct link between the sky will not attract lightning, it will join the electrostatic gap.
In terms of space debris, it turns out that carbon nanotubes are among the strongest things we've ever dealt with. What makes anyone think that with enough nanotubes stronger than diamonds, there are still enough floating screws orbiting the earth to chip away at it? I challenge anyone to put a chip in a diamond with a steel screw.

At up to 18,000 miles per hour, I don't believe anything would withstand a glancing strike. Still, I think that it a cheep enough endeavor that it's worth the risk and expense.

If they can get this to work, it would be a massive leap for energy and space exploration. I would definitely like to see this, even if they use Kevlar.

One of the things to consider is yes this will be a big lightening rod if electrically conducting nanotubes are used. This could be a good thing.
As the platform rises or lowers, the electrical potential will change proportionally. This thought inspired the power cable experiment that destroyed itself when reeled out from the shuttle. The power generated melted the cable at the reel. More reliable data about the power generated would allow engineers to take this into account. Then we wouldn't need lasers at all.

I feel like all of the complainers are extremely lacking. First off, a thunderstorm occurs because their is a negative charge in the clouds and a relatively neutral charge on the ground. A direct link between the sky will not attract lightning, it will join the electrostatic gap.
In terms of space debris, it turns out that carbon nanotubes are among the strongest things we've ever dealt with. What makes anyone think that with enough nanotubes stronger than diamonds, there are still enough floating screws orbiting the earth to chip away at it? I challenge anyone to put a chip in a diamond with a steel screw.

True enough nanotube composite diamonds are +10 on mohs hardness scale, but a hammer will crush them all. Increadibly hard, not so tough.
The ribbon though, yes it will be under tension, but it will still be flexible. trying to crack a ribbon is a different matter. More likely it will catch anything hitting it.

Antialias

Caliban:

lots of new advances in material surfacing for the purpose of shedding water

a) They don't leave the surface dry (not DURING a thunderstorm)
b) they make the surface slippery (which you definitely don't want since it would make your robots slip off the surface, too)

Micron texturing only beads up the water preventing whetting no slippery surface.

the tether could also be employed to "harvest" lightning as a power source and/or to contribute to the grid.

The energy content of a lightning strike is very low (an average bolt of lightning has enough to power a lightbulb for a year). Only the POWER of a lightning bolt (energy/time) is high.

As mentioned earlier, the upper atmosphere and ground act as capacitor plates, the ribbon would ground that. The resistance of the ribbon would limit the current.

I also decided to register to comment...
Next, lets get out of the box and look at some great applications for a space elevator outside of Earth. Having one on the moon would be much easier than on Earth.

I think the moon would be a problem. The moon rotates once in about 28 days right? Where would the geostationary satellite be? On the Earth?

How is the cable controlled when a large thunderstorm storm passes across the lower part of the cable? It might look good on paper but I see it as being in the same league as dirigibles, a fair weather machine only and in danger in a storm.

People, please read the wikipedia articles on the Space Elevator concepts before posting all manner of problems you see. Most have been solved by very clever scientists.
http://en.wikiped...elevator

If I read the wiki link correctly (especially the further link to spacce elevator safety) almost NONE of the hazards has been adressed to the point where the cost could be justified (i.e. where a multi-year operation could be guaranteed) and many of the 'adressed' points (floating anchor/laser broom/metal coating, etc. ) are highly speculative in their approach.

No. Let's just do something more sensible like a launch loop or a mass driver
http://en.wikiped...t_launch

Its a shame they cannot conduct these space elevator tests in a vacuum, because then they could use space elevators with 1KW VASIMR engines

I haven't bothered to read all comments in this thread so forgive me if I duplicate someone's point here, but in case nobody's mentioned it yet, the idea is this: Build a cable out of pure single-strand multi-walled Carbon Nano-tubes which are around 1/10th the weight of Steel, and 100X as strong. This type of cable would be both light enough and strong enough to be capable of being not just the length of Geosynchronous orbit, but twice that distance, which is the actual required distance due to the need to add enough centripital force to keep up the orbiting platform under the weight of the cable.

I read a series of books recently about terrforming Mars, called Red Mars. They build space elevators by capturing an asteroid, putting robotic manufacturing plants on it, and building the cable and spooling it down from the asteroid. That sounds like the best way to do it to me, once technology reaches that level. They also made the tether out of different materials at different heights, to deal with different conditions. Of course, the same novels had the cable severed intentionally and it wrapped around the planet and struck with the force of a nuclear bomb continuously. Still, I think a space elevator is a great idea and would be an amazing acomplishment. I'm sure people will solve all the various problems with it soon enough.

Maybe we will build space elevators on the moon. Because there is no atmosphere, we can use VASIMR engines to power the space elevator.

I also decided to register to comment...
Next, lets get out of the box and look at some great applications for a space elevator outside of Earth. Having one on the moon would be much easier than on Earth.

I think the moon would be a problem. The moon rotates once in about 28 days right? Where would the geostationary satellite be? On the Earth?

Exactly, the earth is at the stationary orbit of the moon, if you neglect the gravity of the earth.

Arthur Clark hypothesized the space elevator. The thought is that his idea of Satellites came true so maybe the space elevator idea is good.
Space junk is a huge problem. The recent tests of space tethers were "cut short" due to space junk severing the tether (sorry for the obvious pun).
My own view is that the space elevator be self supporting/thrusting and be remotely powered by ground and space based lasers. Perhaps it uses a fuel pellet that is vaporized by the laser for thrust. That means no cable is needed, only powerful lasers.

Arthur Clark only supported the idea in the 90's as his age increased.(3001, novel)2 factors virtualy ignored even now are Inertial Shear, and Orbital Shear.Different levels of force on mass will be present at different altitudes.Far beyond strength of nano materials.

Why the complainers dont go make some research before posting crap here?

I have been following Lasermotive for years. The best material we have at present for a stationary space elevator is Colossal Carbon Tubes, not Carbon Nano Tubes. Wiki it yourself, you interested students. Beaming solar power from solar nano-powersats to earth is going to be the nearterm market for this technology. A winged resuable rocket first stage will launch a Vertical Takeoff Vertical Landing resuable second stage. The second stage VTVL rocket will take a 100 pound nano-powersat to a 100 mile altitude, where it will rendezvous with the end of a 200 mile long Zylon tether, called a MXER, in low earth orbit. (This Zylon MXER tether is capable of being built today.) After the nano-powersat is whipped to a 300 mile altitude by the MXER it will detach and inflate its solar panel. It will take 6 months and the energy from the solar panels to fly ITSELF up to GEO with a Nitrogen ion rocket. Once the NPS is at GEO it will beam 5 Kw of laser energy to any 5 sq m rectenna on the surface.

Why not position the space elevator above a dry piece of land, like a desert? Where there's no rain? Why is water such a huge concern when materials exist that easily repel water?

And people who think a space tether would be too heavy, think about this. If you attach a tether to the moon, would the moon fall? No. It's just a matter of getting something big high up in the sky, and it has to be just big enough to work. After that, you can use the smaller space elevator to build some really big ones by piecing them together in space.

Why not just build a skyscraper so tall it ends in space? The base would have to be quite wide. Once in the vacuum of space we can launch 1KW VASIMR rockets from there. We could get to Mars in 3.9 days using this kind of technology.

Why so much pessimism?
I hate you, all who just declare this as impossible. You know, never say never.
It is understandable to have doubts about the concept, especially if you're not an expert on all aspects involved. But instead of just declaring it impossible, you can do some research or even ask some questions and maybe you will see there is a chance for this idea.

Vlasev, yes the cable that is below geostationary orbit will be pulling the station down. But the idea is to also have a counter-weight mass on a cable above geostationary orbit, that will pull it up, and both should balance.

Everything that skeptics point out has a solution, it is just a matter of time and money. Eventually we will get it working.

I agree it is only a matter of time.
IMHO this is purely a structural engineering and materials science excercise. Clearly it obeys the laws of physics.

Wow, the non-engineer "we can do anything if we want it bad enough" trolls are out in force on this thread. Folks, just because someone posts a website documenting their theories doesn't mean they must be valid.

For the record -
1) just because someone isn't a true believer in "space elevators, now" doesn't necessarily mean they are ignorant, it means they've read the available info and came to a conclusion different than the one you came to
2) there is rain in desert (almost spit my coffee onto my keyboard on that one, thanks)
3) the technology doesn't exist to mass produce carbon nanotube cables or ribbons in quantities necessary to build a space elevator
4) the technology doesn't exist to build a long term and survivable mars base or moon base

The contest was about beaming power, not space elevators. And in that context, its really, really cool. Just accept the technological victory for what it is, we don't need fantasy to make this a great moment in engineering!

Many people have mentioned many different technological challenges for this hypothetical space elevator. The way our technology progresses is what will solve this. Each branch of engineering is improving and solving problems in a thousand different areas. Eventually they will converge to come to a solution to this problem. Most fields of science are dependent on others at this point. You need to look at the big picture on this one, not at one single "insurmountable" problem that we all think will never be solved. These problems will be solved, but not in the ways or time tables that we have envisioned. Maybe quantum computing will solve it. Maybe nanoparticles will. Maybe efficient solar power will. Maybe room temperature superconductors will. Probably a combination of all of them, just like today's "impossible" heavier than air flight machines.

Its amazing how people today can act like XIX century fools! They act like those who thought that airplanes were impossible, AC was a mistake, computers would be waste, etc, etc, etc ....

But today skeptics are worst because today we live surrounded by the advances those visionaries brought to us.

Sigh, a bunch of people make many reasonable arguments as to why this isn't feasable NOW, and the true believers ignore ALL the valid arguments and focus on the "non true believer ness" of the writers, and essentially compare us to flat-earthers and Luddites.

Maybe you folks should consider the possibility that dissent from the groupthink mindset needn't be quashed, but instead should be evaluated outside of internal biases, prejudices, and wishful fantasies.

Riiiiight, that'll happen.