h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Who knows anything about nanofibres/tubes?

Just skimming through this website - www.highliftsystems.com, I was surprised to see that the company is already looking for funding. Does this mean that research into nanofibres is extensive? Can we construct a chain of nanos' now? Or is it still a few years off?

Incidentally, their cost projections reckon construction of a space elevator would only cost 10 to 15 billion dollars (US), that's NASA's budget for one year.

The nano tubes stuff was a spin off from the Buckyballs stuff wasn't it? After discovering Buckminsterfullerene they also discovered they could make tubes out of it.

Leastways that's my recollection. Probably wrong tho'!

Can't say I've heard of Buckminsterfullerene. But you could be right. I think nanotubes are a way of constructing a certain type of carbon together.

Buckminsterfullerene is the 3rd form of carbon - C60 - was discovered mid nineties I think and involves arranging 60 carbon atoms in a ball - kinda football (soccer ball!) ish shape.

Nanotubes came out of that research and, as you mention involve making a seamless tube of atoms. Just plugged it into google and yes they do exist. And not only for Carbon but also for other atoms.

Apparently the tubeas are sdo far up to 1mm long, don't sound much but consider you are working with atoms and it is qignificant.

Dunno if you can get external sites, but this is the first one I went to.
http://www.pa.msu.edu/cmp/csc/nanotube.html

I see. So, in theory, construction of a space elevator could begin tomorrow?

C60 is very rare... it would have manufactured atom by atom....

I don't think Buckyballs are that hard to make these days... there just doesn't seem to be much practical use for them other than studying them to see if there are more practical uses for them, if that makes any sense.

The idea of a 'space elevator' in his story "Songs of Distant Earth". In Clarke's words, "Building this would require a material strong enough to stretch all the way from stationary orbit down to the Eqator, without being snapped by Earth's gravit. Such a material was discovered in 1993 by chemists at Rice University, Texas: it's the tubular form of C60, better known as Buckminsterfullerene." (Taken from the 'sleeve notes' for "Songs of Distant Earth" by Mike Oldfield.)

So the people who are looking to build the 'space elevator' probably got the idea from Clarke's book.

There is also some great examples in Kim Stanley Robinson's Mars trilogy. There is a report on the website that explores the constuction methods that both writers employ in each book. It is very interesting.

The Clarke story was "The Fountains of Paradise", which was coincidentally published around the same time as Charles Sheffield's similarly themed "The Web Between the Worlds". The latter includes, in some editions, an addendum with specific engineering calculations laid out for how such a device would/could be constructed.

A device of this nature was depicted (albeit rather unclearly) in the Star Trek: Voyager episode "Rise".

Buckminsterfullerene was first syntesised by accident in the late eighties, although it was certainly recognised as a physical possibility before it had ever been made (my organic chemistry lecturer - who is rather surprisingly now a Labour MP! - referred to it as "soccerballane", I believe before anyone had ever made it).

The space elevator is a necessary, sensible way to get to space - but we'll likely only get one when we have an effective single world government with no pesky dissenting states. Luckily, we appear to be working towards that right now...

H.

Subtle.

At the moment it costs between $25000 and $40000 to get 1kg into orbit. With a space elevator, high lift systems predict it will cost only $400 per kg.

Plus, think of the revenue gained through space tourism!

We should start a pressure group called -insert witty name- that endevours to make NASA see sense.

I agree that Arthur C. Clarke wrote a book called 'The Fountains of Paradise' which featured a space elevator, but the idea *may* have originated in a novella he wrote in the late 1950s. This was 'The Songs of Distant Earth' which was later turned into a full length novel, and inspired Mike Oldfield to write the music of that name. I haven't read either book, or the novella (love the CD, though!), so I don't know where the elevator first appeared.

"I agree that Arthur C. Clarke wrote a book called 'The Fountains of Paradise' which featured a space elevator, but the idea *may* have originated in a novella he wrote in the late 1950s."

I'm pretty sure "The Fountains of Paradise" was his first use of the idea, because he had to point out that he hadn't nicked the idea from Sheffield, and also pointed out that Sheffield hadn't nicked the idea from him - something people were accusing them both of at the time, since they both *first* used the idea at around the same time.

The elevator idea actually first appeared in Komsomolskaya Pravda in 1960, the idea of Yuri Artsutanov. He specifically used the idea of LOWERING a cable from a geostationary satellite - a more practical solution than a previous idea proposed by one of the great visionaries of history, Konstantin Tsiolkovsky, who looked at the Eiffel tower and thought "Why not just keep building up?". A tower such as that would collapse under its own weight - indeed, the lower levels would literally flow out from under it - because it would be under compression. The Artsutanov idea is that the cable is under tension - something which could, possibly, be physically buildable.

More info: http://www.eurekasci.com/SPACE_ELEVATOR/intro.html

Crucial excerpt from that link, for those who can't follow it:

"For the last two years a detailed design study of the space elevator concept has been funded under NASA's Institute for Advanced Concepts (NIAC)."

...

"With a concerted and well-funded effort the raw technologies could be ready in two years, further engineering would be three more years. Once construction begins it will take 6 years to complete construction and launch the initial spacecraft. Two and a half additional years will be required to build up the cable to a 20,000 kg capacity. An operational space elevator could be launching 13,000 kg payloads every 3 days within 13.5 years. Recent analysis is also finding that the first space elevator might be built for less than $10 billion total, including launch costs, and a second elevator would cost a small fraction of the first. "

"The NIAC work has illustrated that not only can a space elevator be built but because of the scheduling aspects of constructing the first and additional cables the institution (country, entity) that builds the first one would have a dramatic lead in space activities for decades if not centuries. "

And finally, and most bafflingly of all:

"Funding for continued development and investment proposals are being sought. "

Given the self-evident incredible advantage that this would offer the institution/country/whatever that builds it, why is funding even an issue?

I'm absolutely AMAZED the French, Germans and Russians haven't already started building the damn thing, frankly - a quicker and more cash- efficient way of permanently stepping on American ideas of "full spectrum dominance" would be hard to imagine.

Then again, given the current administration's dedication to that idea, could we believe that the EU or any other nation would be allowed to develop that technology without having it removed by US military action? Surely the US would not permit such competition from other powers, no matter how peaceful their intentions? And surely, at least until the project was completed, the rest of the world would have no way, no way at all, of stopping the US from preventing the development of the system by use of overwhelming military force?

H.

Wow, this is exactly what I wanted. Well done Hoovooloo, have a pie.

I had no idea NASA were considering it!

The only problem that i can see is the devastation that the cable would cause if it were to fall out of orbit, it could wrap around the world many times. but apart from that, i dont see any problems. why isnt it under construction?

Thank you very much, but as anyone who knows me will tell you, I already ate all the pies...

H.

Hmm, the devestation... that's depicted in Kim Stanley Robinson's Mars trilogy as well, the Martian elevator gets its ballast asteroid blown up and proceeds to wrap itself twice around the planet. Obviously if that had happened on Earth it'd have made much more of a mess, what with tsunamis and so forth, and a much, much higher population (about 10 to 12 billion on Earth at that point I believe, compared to 12 million on Mars at most).

This is one thing I've never quite got my head round the physics of...

The Line (as it is referred to in "Strata", by Terry Pratchett, yet another novel to use the concept, although not centrally, and in 1981) works because it's under *tension*, rather than compression, right? Which means the net force at the tether is UP.

Wouldn't the simplest thing be to have explosive bolts holding the thing in place at the tether point, and if there's any problem at Line Top, blow the bolts and let the whole thing be flung off into space under its own centripetal acceleration? Or am I missing something? And if so, what?

H.

Surely some form of tensioning device would be required at either end. If this incorporated a reel or winding system then perhaps it would be possible to wind up the cable before it did any significant damage. How thick would the "line" be?

In the Mars trilogy they said that if they took out the cable's tether at the Mars end it'd just stay exactly where it was... which is why some of the revolutionaries decided to take out the top and let it fall instead. In the way the cable was envisaged for that series, in order to get it to fly away from Mars they would have had to install a bunch of engines of some sort on it to propel it away from the planet.

Given its proximity to such a large gravitational mass, I suspect most disruptions of a cable like that would probably end up with it falling to the planet eventually, barring further intervention to prevent it that is.

Oh, and in that same trilogy Earth ended up with six space elevators, so if they all came down it'd make a very, very big mess.