Stairway to heaven

[T_i_B]

http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2005/09/25/wspace25.xml&sSheet=/portal/2005/09/25/ixportal.html

Space may still be the final frontier, but getting there could soon be almost as simple as stepping into the office lift at the start of the day.

The race is on to build the first "space elevator' - long dismissed as science fiction - to carry people and materials into orbit along a cable thousands of miles long.

In a significant step, American aviation regulators have just given permission for the opening trials of a prototype, while a competition to be launched next month follows in the wake of the $10 million (£5.6 million) "X Prize'', which led to the first privately developed craft leaving the Earth's atmosphere, briefly, last year.

Supporters of the elevator concept promise a future in space that is both cheap and accessible, and contrast it to Nasa's announcement last week that it will be relying on 40-year-old technology from the Apollo programme for its $105 billion plan to return to the Moon by 2018. The companies behind the space elevator say they will be able to lift material into orbit for as little as $400 a pound, compared with $20,000 a pound using existing rockets. That would open up the possibility of tourists visiting a sky hotel in stationary orbit 22,000 miles above the Earth, with a view previously enjoyed only by astronauts.

[ClintonTyree]

1. Oh god.........

I thought you were going to post the lyrics or something. I was going to have to kill you but I see everything's alright now. ;)

[T_i_B]

2. What? You mean like this?

Where's Rolf Harris when you need him?

There's a lady who's sure all that glitters is gold
And she's buying a stairway to heaven
And when she gets there she knows if the stores are closed
With a word she can get what she came for

Woe oh oh oh oh oh
And she's buying a stairway to heaven

There's a sign on the wall but she wants to be sure
And you know sometimes words have two meanings
In the tree by the brook there's a songbird who sings
Sometimes all of our thoughts are misgiven

Woe oh oh oh oh oh
And she's buying a stairway to heaven

There's a feeling I get when I look to the west
And my spirit is crying for leaving
In my thoughts I have seen rings of smoke through the trees
And the voices of those who stand looking

Woe oh oh oh oh oh
And she's buying a stairway to heaven

And it's whispered that soon, if we all call the tune
Then the piper will lead us to reason
And a new day will dawn for those who stand long
And the forest will echo with laughter

And it makes me wonder

If there's a bustle in your hedgerow
Don't be alarmed now
It's just a spring clean for the May Queen

Yes there are two paths you can go by
but in the long run
There's still time to change the road you're on

Your head is humming and it won't go because you don't know
The piper's calling you to join him
Dear lady can't you hear the wind blow and did you know
Your stairway lies on the whispering wind

And as we wind on down the road
Our shadows taller than our souls
There walks a lady we all know
Who shines white light and wants to show
How everything still turns to gold
And if you listen very hard
The tune will come to you at last
When all are one and one is all
To be a rock and not to roll
Woe oh oh oh oh oh
And she's buying a stairway to heaven

There's a lady who's sure all that glitters is gold
And she's buying a stairway to heaven
And when she gets there she knows if the stores are closed
With a word she can get what she came for

And she's buying a stairway to heaven, uh uh uh.

http://www.brave.com/bo/lyrics/stairhea.htm

[Nomad559]

4. Stairway To Gilligan

http://www2s.biglobe.ne.jp/~pennywiz/Funhouse/gilliganE.html


:evilgrin:

[oneighty]

3. If there were a stairway

to earth orbit one could climb it. Stopping at about fifteen thousand feet for oxygen equipment and a few thousand feet further for a pressure suit of some sort. There would have to be way stations (and porta-potties) for body functions bath and perfumes and such not to mention food and drink.

It would be quite a hike.

I bet.

180

[T_i_B]

13. Well, maybe more of a cable lift

"Stairway" just makes for a better headline. :eyes:

[oneighty]

14. Yes

But you must admit the stairway has much more charm than a mere cable car.

Yes?

180

[RC]

5. Some questions.

How the hell are they going to anchor the ribbon cable to the earth; with a "floating anchor" in the ocean yet?

Has anyone calculated the stress along this 800, ton, 22,000 mile long cable?

This 3 foot wide ribbon will act as a very, very large sail in the wind. There is no getting around that. What happens if it starts to flutter? And it will.

Where are we going to get the power to operate this thing? It is still going to take a tremendous amount of power to get something into orbit because you are still escaping Earth's gravity. And yes, I understand power and gearing.

And beaming power through the the Earth's very turbulent atmosphere to a 2-3 foot target several thousand miles away?



I wonder how much of a tax cut it will take to pay for this thing? With the money involved, you know "private enterprise" will not be able to afford the full cost.

[Richard D]

7. I'd imagine

That there will be some sort of counterweight like regular elevators use.

But what about storms?

[Salviati]

8. Answers to a few questions...

At least the ones that I know off the top of my head at least...

The LiftPort group is planning to anchor to ribbon to a large floating platform.

Calculations on the stress on a space elevator cable was one of the first things done when people came up with the idea over 100 years ago, so this part of the physics is well known about.


They plan to use solar power collected at the spaceside anchor, and beam it back to the car and to earth. The target is likely going to be on the order of 20-30 feet collectors, and hitting them won't be a problem. As it is, we've got people bouncing lasers off of targets left on the Moon, targets that are much smaller, and much further away. (granted, at those distances, even the best laser spreads out quite a lot, but it's still no easy feat.)

Here's their website with a FAQ that covers a lot of info http://www.liftport.com/

[Salviati]

9. dupe

[Pepperbelly]

11. That is why God made ...

engineers.

:eyes:

Geosynch orbit and a floating anchor on terra firma, so to speak.

[mainegreen]

6. Yes, and we can make how much nanotube wire a year?

:rofl:

[Salviati]

10. This is one problem that looks solved now...

Just like a rope is made up of small fibers woven together to prodce a big, strong rope, the carbon fiber ribbon they plan on using isn't made up of a single ginormous carbon nanotube, but rather many small nanotubes woven together to make a ribbon. A new process demonstrates the ability to make about seven meters a minute of ribbon out of millimeter sized lengths of cabon nanotubes.

http://www.dallasnews.com/sharedcontent/dws/dn/latestnews/stories/081905dnmetnanosheet.1c9439ac.html

[Meldread]

12. Hmm... could this be a solution?

What if magnetic levitation were used? You would not need cables.

Here is how I theorize it would work, and keep in mind I'm not a physicist or anything like that and I am only going on my limited knowledge of electro magnetism.

There would basically be two parts, a base and a "ship". The base would basically be a VERY powerful electromagnet. The ship would also be an electro magnet, and I think the best shape for it would be something like this:



or



Minus the holes, of course.

The ship would also be an electro magnet, though its power wouldn't be as strong.

Somehow, to keep the ship stable and from tipping over, it would have to spin in a circle. Once that is happening, you could then turn both the electro magnets on, having the bottom electro magnet's pole going north, and the ships electro magnetic northern pole pointing south - so that they are "repelled" away from each other. The spinning should, in theory, keep the ship stable and from tipping over.

There is, of course, the issue of centripetal force. Perhaps the ship has an outer shell that is the electro magnet that "floats" around the inner shell.

Anyway, the idea is to combine magnetic levitation with magnetic propulsion. While the ship is stable, have the bottom electro magnetic energy increased.

In my head I imagine having the ship levitating using magnetic levitation, and then "floating up" into space using magnetic propulsion - essentially forcing itself away from the Earth.

Not sure if it would work, but it seems feasible. I'm just not sure how much energy it would take and if the energy required would be too much.

[mainegreen]

15. I can't imagine that if that worked it would be a good idea.

First off, don't magnetic fields get exponentially weaker as the distance from the source increases? You might make it half a mile up, but after that you power needs would be huge. Plus I don't like the idea up setting up HUGE magnetic fields all over the earth. Think of all the bad things that might happen. Migratory birds get confused, compasses become unreliable with multiple poles all over the earth, perhaps even new paths for high-energy particles to earths surface will be opened up due to this. It seems mighty dangerous to me.

[phantom power]

16. fields decrease as the inverse cube.

Doesn't change your main point. They're unuseable over any significant distance.

[Salviati]

17. Actually, as the inverse square of the distance...

But likewise, it doen't change the gist of the arguement...

[phantom power]

18. As distance grows, behavior asympotically approaches inverse-cube.

Somebody actually posted the derivation:

http://www.math.bcit.ca/examples/elex/algebra_geometry/

[Salviati]

19. That's true...

For the case of a bar magnet (or any simple magnet really), since it acts like a dipole field. I was thinking of just a monopole field, which is not really applicable for magnets, my bad...

[phantom power]

20. Maybe someday we'll isolate monopoles. That would be cool.