http://www.spacedaily.com/news/materials-03w.html

Seems the space elevators of science fiction fame may not be so far off, after all.

"The NASA Institute for Advanced Concepts (NIAC) commissioned Dr Bradley C Edwards to study all aspects of the construction and operation of a space elevator, and Phase I of the report was published in late 2002.

The report very specifically addresses design and operations, which had until then escaped close scrutiny.

Firstly, the elevator would not be a cable. It starts as a 1-micron thick piece of tape 91,000km long, tapering from 5cm wide at the Earth's surface to 11.5cm wide near the middle. This tape would be taken up by shuttle together with some booster rockets. It would then be 'flown-down' to the surface whilst the booster rockets provide the required counterbalance beyond geosynchronous orbit.

Centripetal force throws the higher part of the tape away from the Earth, whilst the effect of gravity on the lower mass of the tape keeps it in tension. This first link is capable of supporting 1238kg before breaking."

This won't work, is very risky, and costs billions if even tried to build. The thinbg could fall down and it would crush anything under it. It would get in the way of aircraft. It would just collapse onto itself for nothing can hold that much weight for any length of time. Terrorists could blow it up. Where would it ne built, they won't want it to fall onto them. This project shouldn't even be discussed for everything about it screams it's IMPRACTICLE and USELESS.

this stuff weighs less then paper, it won't kill anyone. Rockets, now they kill people. I believe brazil just lost 20 people as they were testing a rocket engine. Nanotubes are far stronger then anything else ever made, its definetly strong enough to build a space elevator out of. They plan on having the space elevator anchored to an ocean platform, which can then move around and avoid things like hurricanes. Also it will reduce the costs of going into space at least a 100 fold, instead of a 1000 dollars per pound we're talking about 10 dollars per pound. Spave elevators will undoubtedly open space for humanity, and not just astronauts. Cosmic, you are a stupid person.

Plans seem pretty feasible.

We will probably figure how to make really long carbon wire/tape within 5 years and from that point human curiosity to explore will inevitably find a way to find the money to invest.

The thing is it is, it is a financial risk cause it aint proven launch platform/technology, it would be nice if we have another space race like we had with usa/russia in the past, but this time usa/chine. You could bet the americans could suddenly find the resources/people and money to make this thing fly if they fear china might become the first to have a stairways to heaven...

Or even better, some rich muslim oil state should have the spare pocketmoney to build something like this, surely the americans / cristians could not bare the thought of former goathearding muslims having the largest twin towers (Petronas) AND a spacetower, this would be the kind of competition we really need to make big things happen fast.

How is it that paper can lift something that weighs over 5 tons? How is it going to actually lift anything without power and where's the power going to come from? A moveable barge won't move fast enough with that much weight on it to get out of the way of a hurricane.It isn't logical whatsoever and shouldn't be built or even thouight about. Whoever builds it is a damn fool and wacko for spending that kind of money on a worthless project like this.

This does seems rather inexpedient and haphazard. One has to consider the likelihood of lightning, hurricanes, volcanic and/or surface conflagrations, other natural calamities, and the risks these pose to such flimsy fibers. Besides, wouldn't the heat absorbed by the cable in be immense? There could be stupendous levels of thermal expansion and consequent weakening to deal with.
Imagine the tension of that material! Gravity and centripetal force and probably a dozen other extreme factors! So these Carbon Nanotubes are that durable?

hey, neat article, thanks for posting it!

ive always had the Aurthur Clarke/Kim Robinson vision of an elevator in my mind (therefore 150 years away at best - not to mention the devastation a failure could cause) so its interesting to read about this more plausible (for our century) and safer design.
Whoever builds it is a damn fool and wacko for spending that kind of money on a worthless project like this.
were your parents killed in an elevator crash or something? your getting pretty worked up considering its still a theory. you call it worthless? if you want to discuss worthless projects lets talk international space station - now that truly does nothing (the worst part is we knew that before we built it) yet we spent an ass load on it anyway. Unlike the space station an elevator actually has potential uses.

As far as it being dangerous, im sure dangers are involved (as with anything) but compared to having to ride a controlled explosion to escape the planet's gravity (as is the case in every method used to date) it seems hard to argue an elevator would be more dangerous.
There could be stupendous levels of thermal expansion and consequent weakening to deal with.
Imagine the tension of that material! Gravity and centripetal force and probably a dozen other extreme factors! So these Carbon Nanotubes are that durable?
I think the article mentioned that excess energy may be a problem and methods of dispersal are being looked at, I assume they won't start construction until these issues are addressed. After all this is just the start, there is still a long way to go.

arg, thank god I'm moving to that biology forum...tired of this junk. First off the only heat the elevator is exposed to is that from the sun, nothing major. The heat you probably are thinking about is that created when an object enters the atmosphere, and that is created by the friction with the air. Since the space elevator is *NOT* moving through the air at 10,000 milers per hour, it will NOT burn up in the atmosphere. And yes, nanotubes are freakin strong. The space elevator will essentially be one enormous molecule. Contruction would cost roughly 20 to 30 billion dollars, and be a solid money maker once constructed. An elevator would climb the shaft, using power sent to it by a laser.

A space elevator would need to taper, as all the weight of the lower parts will be carried by the upper parts. Any breaks would be likely to occur in the thin lower levels; the thicker upper levels would then fall upwards, strange as this may seem.

There are many different configurations involving shorter tethers and lifting mechanisms; lofstrom loops, skyhooks, rotating tethers, space fountains and dynamic orbital rings.

Of these the skyhook and rotating tethers are relatively easy to achieve, and involve a rendevous between fast moving atmospheric craft and a moving tether suspended from a satellite.
Before beanstalks become possible I would expect something along these lines to be tried in earnest, as the cost of lifting mass to orbit is so great.
__________________
SF worldbuilding at
http://www.orionsarm.com/main.html

Did you guys ever read Battle Angel Alita?

The weight on the bottom is supposed to be counterbalanced from the other end (the one in orbit). That means, first of all, that the stresses would tend to be in the middle.

Second, this thing doesn't need to be attached to the ground. It could instead be counterbalanced at 10km off the ground, or some such distance, and easily be above the range of ground fires, hurricanes, volcanoes and so on. The most major problem that occurs to me is stabilizing the thing in geosynchronous orbit, which would take vast amounts of power for something so large.

Anyway, remember that something OUTSIDE of geosynchronous orbit moving at geosynchronous speeds will tend to fall AWAY from the Earth, and anything INSIDE it will tend to fall TOWARDS the Earth, hence the counterbalancing effect. We need only be sure that it weighs about the same on both sides.

Simple:D

The weight on the bottom is supposed to be counterbalanced from the other end (the one in orbit). That means, first of all, that the stresses would tend to be in the middle.

That is true, but in most design studies the end that points away from the centre of gravity terminates in an asteroid or other heavy counterweight, and is much shorter;
the end that reaches earth does not need a wieght on it, as it is heavy enough as it is.
__________________
SF worldbuilding at
http://www.orionsarm.com/main.html

As an engineer, I'll repeat my position on the space elevator: impossible, impractical and waste of money to even try with today's technology*. Doesn't even make good sci-fi. You're far better off keeping your eye on fusion tech for that magic space launch system.

While it's good that they're looking into it, the practicality of this is so far off that I wouldn't be surprised a bit to learn that this is a trojan project to see what interesting technologies fall out of it. I think that everyone here will have long since passed out of living memory before any meaningful moves are made toward a space elevator, and maybe a generation after that when it becomes practical.

* And the projected technology of the next half century, so don't get your hopes up.

Some alternative concepts that have 'fallen out' so far

rotating tethers
http://www.space.com/businesstechnology/technology/tether_tech_030618-1.html

mass pellet driven space towers
http://www.islandone.org/APC/Tethers/03.html

dynamic orbital rings
(ok this one is mine, and it's sf, but based on an idea by Paul Birch of the British Interplanetary Society
http://www.orionsarm.com/eg/d/Du-Dz.html#dynamic_orbital_rings

What a bunch of bullshit!

Curses- someone noticed!

more-
lofstrom loop-
http://www.islandone.org/LEOBiblio/SPBI116.HTM

--------
rotavator
http://members.aol.com/Nathan2go/lunavat.htm
--------
skyramp
http://www.skyramp.org/

---------
mooncable
http://home.earthlink.net/~jedcline/mcbl2.html

Lets build space station Babylon 5, Deep Space 9 or the Death Star in Orbit ..........it might make more sense:(

I think a maser or laser launch vehicle system would be cheaper more versatile
http://www.islandone.org/APC/Beamed/06.html
as opposed to
http://www.islandone.org/APC/Tethers/03.html

Why not use the tree from Jack and the bean stalk

how long would a launch ramp need to be in order to maglev/railgun equipment into space without destroying it? it seems like it might be easier to railgun our materials into space and assemble them there. perhaps have very small robots build larger ones, which would then build larger ones, which would then build our space stations. All of it starting small enough, and hardy enough, to withstand a railgun's acceleration. just a thought.

All the comments are good, even the very negative ones. It appears the CNT ribbon will not be strong enough for a starter thread with a cross sectonal area of one square millimeter. Thicker and/or wider means rapidly escalating cost and the need for a heavy lift rocket to get it to Geo orbit or splice many separately lifted to space segments. A dozen other problems may be show stoppers. I agree a supersonic rotating tether has a better chance of sucess and will test in part the feasability of the much more useful space elevator. The motors that propel the lift robots/ climbers will get hot. Heat is difficult to dispose of in a vacuum. The laser beam that powers the lift robots will heat the ribbon dangerously close to the failure temperature of the epoxy binder at least occasionally. Neil

Hereis a paste from a tread I wrote about a year ago. Post subject: Alternative space elevator
Some apparently brilliant people think we can't build the space
elevator as Dr. Edwards envisions, so let's analyze some
alternatives. Space rated tether may fall short of projections
for CNT = carbon nano tube. Segments 3700 kilometers =
2200 miles long, 20 micrometers thick, 100,000 micrometers
wide = two million square micrometers = 2 square millimeters
= 0.02 square centimeters = 0.02 grams per cm length = two
grams per meter of tether = 7,400,000 grams of CNT =
7.4 metric tones of CNT if the average density is one
(same as water). This permits starting construction as soon
as 1% of the required CNT = carbon nano tube is available,
even if the CNT is slightly substandard. This can be launched
from the space shuttle or several other existing launch systems.
Corealis effect will make it more horizontal than vertical, but
an ion engine pulling one end to an atitude of 4000 kilometers
will make it approximately vertical in a few weeks. Gravity and
centripetal force help, but they are slow. A half ton climber
can start moving on the tether as soon as the first kilometer
has been unwound off the reel. The climber can get its power
from surface of Earth lasers just as Dr. Edwards plans, except
the solar panel is a moving target. If problems occur at 4000
kilometers, we may have to rethink laser propulsion. Control
of the climber should be temporarily from the space shuttle
as it may be some help in unwinding the tether. The climber
can start adding a thread before the tether reaches vertical.
At 37 kilometers per hour, average, it will take 100 hours to
add one re-enforcing thread. Hopefully improved models can
lay thread faster. After the thread is in place the reel will be
released making the climber lighter and faster. Fast start
and direction reversals will be tested making transients of
various kinds on the tether. A stretch transient will reflect
back and forth between the ion engine and the climber with
a period up to one day, if the transient moves at an average
speed of 308 kilometers per hour. Maximum resonance will
be attempted to learn how to make, utilize and surpress
transients. This tether should attempt to snatch a payload
from Earth's upper atmosphere with a compression transient
as this may be a partial alternative to a laser powered elevator.
A lot of energy is stored in a transient on a 100,000 kilometer
tether. The climber needs to be tested at full power, in
vacuum, in sunlight AND bathed in the energy from the Earth
laser to be sure it will not overheat. Likely a large radiator
will be necessary to dispose of waste heat.
Assuming the first segment looks good, ten are needed to
geo altitude, 27 to the far end = 100,000 kilometers altitude.
The tether slows as each segment is added, until the tether
is stationary (except for trancients) with respect to the
equator of Earth, before the last segment is added. This
shorter segment is designed to be reliable in Earth's
atmosphere. The weight of last shorter segment pulls the
entire tether downward slowly to the anchoring point on an
at sea platform. Ballast is enroute to the far end to stop the
tether from falling toward Earth. A properly timed
compression transient (10 day period?) can help restore
tension after the tether is attached to the at sea platform.
I'm sure I have some errors, so please correct, embellish
and/or comment. Neil

And then some jerk in a Cessna flies right through it!

The ribbon will be black so even an alert pilot could crash into the ribbon. The plane would likely be totaled. Any chance the ribbon would be unsevered? Neil

Space Taxi

Create a SPACE PULLEY instead of Space Elevator.

We can have a pulley hanging form space just above the atmosphere. The pulley hangs from a geo-stationary Space Taxi Station.

A small Space Taxi is released up using a very very large helium balloons. A platform can be made that has large number of huge helium balloons below it. The Space Taxi is stationed on this platform before the whole platform is released.

When the platform reaches to the limit that it rise up in the atmosphere, Space Taxi takes off form the platform using jets propulsion and quickly reaches to the hook of the Space pulley which is just above the atmosphere and hooks itself to it. After this the Space Taxi station just pulls up the Space Taxi.

Note : All this is done with minimum fuel requirements compared to the other technologies, so what say ?

PS. A compressor can be used to bring the balloon Platform back on earth.

A compressor needs lots of energy, otherwise it is a good way to reuse the helium. The world supply of cheap helium is inadequite for lots of "very,very large" balloons. Hydrogen presents a negligible fire hazzard as long as the balloons stay above about 50,000 feet. Mathematicians claim launch from 50,000 feet is not as beneficial as we think, but it is a valid method of getting into space. One of the problems is we need to accelerate about 17,000 miles per hour to reach LEO = Low Earth Orbit. Neil

1) A compressor needs lots of energy, otherwise it is a good way to reuse the helium.

2) The world supply of cheap helium is inadequite for lots of "very,very large" balloons.

3) Hydrogen presents a negligible fire hazzard as long as the balloons stay above about 50,000 feet.

4) Mathematicians claim launch from 50,000 feet is not as beneficial as we think, but it is a valid method of getting into space.

5) One of the problems is we need to accelerate about 17,000 miles per hour to reach LEO = Low Earth Orbit. Neil

PS> wont it be cheaper to launch from mount everest, or the tallest mountains in the world ?

Thank Neil Cox, Atleasts there are some brainy people left in this forum who would respond to my posts.

1) After lanching it dosent matter how long the balloons take to come back down, hence a solar compressor would help in reducing the launch pads weight.

2) I didnt knew that, why cant we make more ?

3) Why cant we create smart material balloons that will never leak the hydrogen, after all dont we use hydrogen for propulsion today ? these days people also talk of hydrogen cars.

4) I think Any cost saving should be welcomed. Are U telling here that balloons cant go beyond 50000 feet ?

5) So ? Wont it be better if we get low air resistance and greater height to reach there ?

Launching from tall mountains helps. Unpleasent for the humans is the main hold up. Improved robotics may make launch from moutain tops practical by the time we have a launch site constructed on a high mountain top. 1 Do you have a design for a solar compressor in mind? How long may matter. Time is money if there is a back log of customers ready to launch. 2 Nearly all helium is separated from natural gas and volitiles in petrolium in a few locations. At present helium is a low value by-product. High demand would increase the price by perhaps 100 times before it would be cost effective to extract the tiny amount of helium from the atmosphere. 3 Linde claims they have a non-leaking tank for hydrogen cars, so it is likely possible to reduce the hydrogen losses from balloons. 4 Potential cost savings are often ignored for various reasons. I think 130,000 feet is the record altitude for a balloon, but the payload decreases rapidly above about 50,000 feet. 70,000 feet might be the best trade off for your launch platform. 5 I agree lower air resistance is likely more important than being closer to space for your space pully and platform 6 mechanical friction at thousands of points along your pully system may be the show stopper which is why magnetic levitation is one alternative being considerd. Neil

how long would a launch ramp need to be in order to maglev/railgun equipment into space without destroying it? it seems like it might be easier to railgun our materials into space and assemble them there. perhaps have very small robots build larger ones, which would then build larger ones, which would then build our space stations. All of it starting small enough, and hardy enough, to withstand a railgun's acceleration. just a thought.
As far as I know the French Bullet train is the closest to a large scale fast rail gun built to date. Much faster would be necessary to reach GEO or low Earth orbit even starting from the top of a very high moutain, mostly due to air resistance. It might be possible to build a rail gun 29,000 feet tall using CNT = carbon nano tubes, but we need to work up gradually to such a monster or we will make too many costly errors. The CNT is not yet available in construction quantities, and it may not be worth the high cost for most applications when it is mass produced. Neil

" mechanical friction at thousands of points along your pully system may be the show stopper which is why magnetic levitation is one alternative being considerd.
- Neil Cox"

Whats that ? there is gona be only one point of friction.

Launching from tall mountains helps.

doesn't an elevator have to be anchored from the equator?

There isn't much equatorial land (above sea level) to begin with so I think just finding a place to put it, let alone one that could handle the kind of air/sea traffic an elevator would have, is a bigger issue than altitude or planes crashing into it. After all, illuminating the small part of the elevator that intersects commercial or military airspace is a tiny issue compared to actually building the thing.