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Hermit
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Space Elevator
« on: 2008-10-04 07:12:04 » |
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A new space race is officially under way, and this one should have the sci-fi geeks salivating.
[ Hermit : The elevator could be constructed beginning today. It needs a port, a manufacturing facility and a nuclear power station at its base. It needs the cost of Carbon Nanotubes to come down by at least an order of magnitude. It needs an automated space based carbon Nanotube factory. It needs a low cost recyclable heavy lift to orbit delivery system that does not use fuel wastefully (likely relying on aerostatic high altitude staging platforms at 100 to 300 mile altitudes). All of these things can be worked on immediately, and some have good answers immediately. In parallel, a space solar project, which will not rely on "solar panels," needs to be begun. This will require huge, resilient, light weight and low cost solar mirrors, a high efficiency low cost converter from dense photon energy to high power electricity, seriously high power focused laser and wide area microwave transmitters and receivers (to power mobile and stationary power receivers respectively), and position keeping drive systems. None of this is so far outside the scope of existing technology to present major threats to the project. Both of these projects need emergency funding and focus, because if we don't have them before fossil fuel becomes too expensive for this project to maintain support, then we will never attain this. And given that no source of energy other than the solar system's only functional fusion reactor, collected in space, has the potential to deliver more-than-adequate supplies of extremely cheap power, to maintain the existing population of the planet as fossil fuel becomes too expensive to fill that position, people need to recognize that this is a genuine "existential threat" and desperately needed life saving technology.
The down side is that every day wasted by not supporting this project makes it less likely that we will ever attain it. And if we don't have it by 2030 or 2040 the industrial society required to support and instantiate this will almost certainly no longer exist. ]
Source: CNN
Authors: Mike Steere
Dated: 2008-10-04
The project is a "space elevator," and some experts now believe that the concept is well within the bounds of possibility -- maybe even within our lifetimes.
A conference discussing developments in space elevator concepts is being held in Japan in November, and hundreds of engineers and scientists from Asia, Europe and the Americas are working to design the only lift that will take you directly to the one hundred-thousandth floor.
Despite these developments, you could be excused for thinking it all sounds a little far-fetched.
Indeed, if successfully built, the space elevator would be an unprecedented feat of human engineering.
A cable anchored to the Earth's surface, reaching tens of thousands of kilometers into space, balanced with a counterweight attached at the other end is the basic design for the elevator.
It is thought that inertia -- the physics theory stating that matter retains its velocity along a straight line so long as it is not acted upon by an external force -- will cause the cable to stay stretched taut, allowing the elevator to sit in geostationary orbit. [ Hermit : Rather than "it is thought" which is very weak, "Physics we have understood since the 1700s tells us," which is extremely strong, would be much more appropriate here. ] [/i]
The cable would extend into the sky, eventually reaching a satellite docking station orbiting in space. [hermit : the elevator would begin in the center and extend out in both directions. ]
Engineers hope [i] [ Hermit : Politicians "hope." Engineers, if they are engineers, calculate. This reporters apparently cannot tell the difference. ] the elevator will transport people and objects into space, and there have even been [ Hermit : Amazing. Why "even been" with its implicit skepticism? Disposal in space is a perfectly viable use of "nuclear waste", although I personally think that "future fuel" is a better name for it and that we should be cautious disposing of anything which is scarce where we cannot put our hands on it should we or our successors discover that we need it. ] suggestions that it could be used to dispose of nuclear waste. Another proposed idea is to use the elevator to place solar panels in space to provide power for homes on Earth.
If it sounds like the stuff of fiction [ Hermit : To this reporter perhaps. ] , maybe that's because it once was.
In 1979, Arthur C. Clarke's novel "The Fountains of Paradise" brought the idea of a space elevator to a mass audience. Charles Sheffield's "The Web Between the Worlds" also featured the building of a space elevator.
But, jump out of the storybooks and fast-forward nearly three decades, and Japanese scientists at the Japan Space Elevator Association are working seriously on the space-elevator project. [ Hermit : I, Keith Henson and many others have been monitoring this field and the required technologies since the early 1970s when it became apparent to anybody with a functioning forebrain that this was the only rational low cost route into space, exactly how large the threat of resource depletion was, and that space solar power was the only viable sustainable, low cost solution to our power requirements. It became clear to some at least, with the advent of the long predicted tubular form of Buckminster Fullerenes in 1991 that we had a material with the strength required and that all the other technological requirements could be met and that we should be focusing all our energy onto this project. Keith also theorized a method that will likely produce a two order reduction in the cost of producing the needed buckytubes, but has instead wasted his time chasing and being chased by scientologists and their allies (which may be one of the most stupidly expensive mistakes ever made by any society anywhere at any time). ]
Association spokesman Akira Tsuchida said his organization was working with U.S.-based Spaceward Foundation and a European organization based in Luxembourg to develop an elevator design.
The Liftport Group in the U.S. is also working on developing a design, and in total it's believed that more than 300 scientists and engineers are engaged in such work around the globe.
NASA is holding a $4 million Space Elevator Challenge to encourage designs for a successful space elevator. [ This is a small fraction of the required resources and ought to be regarded as an embarrassment proving how horribly incompetent NASA is at allocating resources.
Tsuchida said the technology driving the race to build the first space elevator is the quickly developing material carbon nanotube. It is lightweight and has a tensile strength 180 times stronger than that of a steel cable. Currently, it is the only material with the potential to be strong enough to use to manufacture elevator cable, according to Tsuchida. [ Hermit : Actually I'm sure this reporter is mistranslating. The strength of an object (which is a far from simple term, in this case actually requiring tensile strength, stiffness and toughness (resilience) depends solely on the material and the structure chosen. The tubular fullarenes are already quite strong and stiff enough to produce a space elevator, not potentially strong enough. All that is required is a suitable structure, a number of which are viable, and which is chosen will depend mainly on the fabrication technique selected. Personally I favor a strutted pentagonal arrangement as proper design would allow the failure of any one strut without imperriling the structure as a whole. ]
"At present we have a tether which is made of carbon nanotube, and has one-third or one-quarter of the strength required to make a space elevator. We expect that we will have strong enough cable in the 2020s or 2030s," Tsuchida said.
He said the most likely method of powering the elevator would be through the carbon nanotube cable. [ Hermit : I am partial to a system design that will have Hydrogen and Oxygen being formed at the base and pumped to many small distributed generators powering aluminum track coils embedded in the structure. The track would then act as a magnetic monorail as well as a power distribution system. This has the virtue that the generators could produce power to be stored between cars passing them, and easily deliver the power in the brief moment during which a car passed them. This seems to me to be the lightest failsafe method of powering them over the distances involved while requiring only moderate design compromise to establish the needed gas passageways. ]
So, what are the major logistical issues keeping the space elevator from being anything more than a dream at present?
Massachusetts Institute of Technology aeronautics and astronautics Professor Jeff Hoffman said that designing the carbon nanotube appeared to be the biggest obstacle.
"We are now on the verge of having material that has the strength to span the 30,000 km ... but we don't have the ability to make long cable out of the carbon nanotubes at the moment." he said. "Although I'm confident that within a reasonable amount of time we will be able to do this."
Tsuchida said that one of the biggest challenges will be acquiring funding to move the projects forward. At present, there is no financial backing for the space elevator project, and all of the Japanese group's 100-plus members maintain other jobs to earn a living.
"Because we don't have a material which has enough strength to construct space elevator yet, it is difficult to change people's mind so they believe that it can be real," he said.
Hoffman feels that international dialogue needs to be encouaraged on the issue. He said a number of legal considerations also would have to be taken into account.
"This is not something one nation or one company can do. There needs to be a worldwide approach," he said.
Other difficulties for space-elevator projects include how to build the base for the elevator, how to design it and where to set up the operation.
Tsuchida said some possible locations for an elevator include the South China Sea, western Australia and the Galapagos Islands in the Pacific Ocean. He said all of those locations usually avoided typhoons, which could pose a threat to the safety of an elevator.
"As the base of space elevator will be located on geosynchronous orbit, [the] space elevator ground station should be located near the equator," he said.
Although the Japanese association has set a time frame of the 2030s to get a space elevator under construction -- and developments are moving quickly -- Hoffman acknowledges that it could be a little further away than that. [ Hermit : Too late and not sufficiently aware of the other factors at play. Had one asked Theodosius I how long the Roman Empire would last, I am sure he would have responded "forever." Yet only 14 years after his death, Rome was sacked. The factors leading to this were many and complex, yet the result was predictable to a number of observers of the day. So too with us.]
"I don't know if it's going to be in our lifetime or if it's 100 or 200 years away, but it's near enough that we can contemplate how it will work."
Building a space elevator is a matter of when, not if, said Hoffman, who believes that it will herald a major new period in human history.
"It will be revolutionary for human technology, and not just for space travel. That's why so many people are pursuing it," he said. "This is what it will take to turn humans into a space-bearing species." [ Hermit : With this I have no disagreement. ]
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With or without religion, you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion. - Steven Weinberg, 1999
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Fritz
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Re:Space Elevator
« Reply #1 on: 2008-10-05 12:59:10 » |
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Well it seems some Memes are in fact expressing themselves; from last year, TopGears class clown no less.
Lets hope this starts to be taken seriously
Cheers
Wally
Source: Times
Author: Jereny Clarkson
Date: 2007.02.04
A couple of weeks ago Sir David Attenborough went on the BBC — an Establishment double act that’s hard to top — and explained exactly what global warming would mean for Britain.
In short, some householders in Worcester will need new carpets every time it rains, the Glasgow sewers will burst and a farmer in Abingdon will be moved to make way for a new reservoir. It was not even slightly terrifying, but nevertheless at the end Attenborough came onto the screen in big nose-hair close-up to explain that we must do something now — now, d’you hear — to prevent this catastrophe.
Doubtless a party political broadcast from such an authority as Attenborough will have had you scampering round the house turning off the lights. And maybe the next day you walked to work instead of taking the car. Though I doubt this, because much to the annoyance of the producers the next day was bitterly cold with snow falling in many parts of the country.
And anyway, even if every nation meets its obligations under the Kyoto agreement, the Earth won’t be saved. In fact, the heat expected in 2020 would arrive in 2026. So we ruin our lives to buy just six more years.
The fact is this. Global warming’s coming, so you can don your King Canute hat and stand on the beach waving your Toyota Prius at the advancing heatwave, but it won’t make a ha’p’orth of difference.
But don’t worry, because I have a plan. The biggest threat we face, according to the British Broadcasting Corporation, is rising sea levels. Apparently, seawater expands when it’s heated, so the entire population of Britain will have to spend the rest of time perched on top of Ben Nevis.
Plainly, then, there is too much water in the world, so why don’t we just call Nasa and ask it to take some of it into space? Technically this is not difficult. Build a fleet of space shuttles. Fill them with seawater. And move it into orbit.
If necessary the water could be stored in a huge balloon so that if the world cools down at some point in the future the shuttles could go up there and bring it back again.
Brilliant, yes? But having given the matter some thought, I think there is room for improvement.
Space is only 75 miles from the surface of the Earth, so why not make a giant hosepipe, dip one end in the sea and take the other end out into the void, where, of course, there is a vacuum. That means the water will be sucked up the pipe without the need for any energy-absorbing pumps.
Of course there is a small problem with this idea. Gravity means the hosepipe will keep falling back to the ground again, but I’ve thought of that.
Initially, I reckoned it could be tethered to the moon, but having studied astrological charts I’ve realised that in a day or two the pipe would be wrapped round the world. And as any gardener knows, this will cause a kink at some point, which will stop the water being ejected.
There are two ways of addressing this. We could either build a tower 75 miles tall to which the hosepipe could be fixed. Or we could fit the space end of the pipe with a watering can sprinkler attachment that is turned to face Earth. This would direct the water downwards and that would invoke Newton’s third law. Hey presto: the effects of gravity are overcome and the hosepipe stays up.
Now I’m just a middle-aged bloke with no engineering qualifications whatsoever and yet, in the space of one afternoon, I have devised a simple method that will save the life of everyone in Norfolk, Holland and the Maldives.
Which brings me on to an important question. What, exactly, are those who do have engineering qualifications doing to fill their days in these dark and superheated times?
Are they developing an airborne vacuum cleaner that cruises through the upper atmosphere sucking up the carbon dioxide and turning it into money or cheese or something? Are they working on waterproof carpets for the people of Worcester or pills to reduce the amount of sewage produced by Glaswegians? Sadly not. In fact they’re all down at the Dog and Spanner wondering if a front differential might tame the understeer in a powerful front-wheel-drive hatchback. <snip>
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Where there is the necessary technical skill to move mountains, there is no need for the faith that moves mountains -anon-
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