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Notes From 3rd Annual Space Elevator Conference
colonist writes "The Space Elevator: 3rd Annual International Conference was held recently. Blaise Gassend, a PhD student at MIT, took notes. The main obstacle is still the material: transferring the strength of the nanotube to the ribbon. Other topics include: the nanotube tether Centennial Challenge; Elevator 2010, a challenge for a 250 kg climber to climb a 16 km tether; objections and refinements to Bradley Edwards' design; non-equatorial space elevators; replacing the term 'space elevator' with 'space bridge'; testing the space elevator material on cable cars; science; defense and economics."
This page seems to have some good links. Just check out the bottom of the page as it indicates if you're new to the idea of space elevators.
How on earth are they going to cope with the wind forces, the jetstream, gravity, the earths spin, earpopping, in transit entertainment, lightning, costs, kids, aliens, terrorism and the fact that their's nothing in space to go up to yet.
P.S.
EMACS already does this.
May the Maths Be with you!
Wikipedia have a very good article on space elevators
Normal GPS satellites are not in geosynchronous orbit.
Some augmentation satelites are though.
Jeroen
Secure messaging: http://quickmsg.vreeken.net/
The space elevator is a great idea but no human has the mental strength to listen to elevator musak for the length of time the trip will require and still retain their sanity.
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
I think that it should be taken into consideration that almost every major project of construction was deemed impossible. Very good examples of these are the famous Golden Gate Bridge and the EuroTunnel. Everyone said it was impossible, yet they were completed. As technologoy in this area continues to develop, I think that this may be able to become a real and practical idea sometime down the road. It may not be possible now, but in ten years, who knows?
Ursäkta, men jag fattar INTE vad du säger?
SIG: TAKE OFF EVERY 'CAPTAIN'!!
I believe the point is to make access to space economically practical. Burning massive amount of fuel is pricey and pretty bad for the environment. If we really want to be doing stuff in space we either use space elevators or wait for someone to invent anti-matter drives or something.
---
We spoke for about a half an hour. I don't recall a thing we said. - Colorblind James Experience
Blaise Gassend's page mentions Andrew Price's list of alternative names:
space bridge
space way
space rail
'Space bridge' got the most approval from the audience.
Forgive my ignorance, MEMS and Nanotech has fascinated me for a while, but I don't know enough of the math behind them to tell if this is true. My grandfather, rest his soul, once told me of something called the Sailor's Rope Rule, which effectively says that the weight a rope can support is diminished by its length. Thus, a 500 lb. rope might support 500 lbs when there's less than a foot or so in length between the pully and the weight, but might only support 250 lbs when there is a good 100 ft. or so... The actual support degradation of course depends upon the width of the rope and the material the rope is made of.
So what I'm wondering is, does the same apply to the weight supported by nanotubes and other molecular chains. I figure it has to be less of a degradation due to the ionic bonds involved, but it would seem to me that, unless some Quantum rule is involved dealing with extremely small-scale weight supporting chains, that they might never overcome this problem due to the sheer thinness of the tubes, chains, etc. It might be extremely strong material, but if it's width is only a few atoms wide, wouldn't this material be, at least in single lengths, more or less useless by the time it got to a respectable length? This is, of course, excluding bundles, which make the most sense, I'm really just curious if the same rule applies to nanotubes as applies to rope.
-The Libra
"Please be patient--The future will begin momentarily."
Not in the fairytail....
But there is archeological evidence for a lot of towers in what is now Iraq and Iran.
Among them some very big ones in babylon.
Jeroen
Secure messaging: http://quickmsg.vreeken.net/
According to new Nasa research http://www.nasa.gov/news/highlights/index.html they can fully fund a new US$2 billion research project by selling the franchise to the revolving restaurant at the top and logo placement along the length of the ribbon itself. Already, they have received competitive bids from Chez Panisse, McDonalds, and Bert Farnsdale's New York hotdog stand. This is the start of the holy mothership of bidding wars.
consider coffee a lubricant that helps one penetrate the coding zone
Well, actually, a little further out than GEO, so that the center of mass is at GEO.
As for wind -- well, you situate it where the wind is minimal. Remember, since it's synched, it's not generating "wind" by slicing through the air. All you'd have to worry about is the wind that is actually blowing past the (stationary) Earth.
The Mongrel Dogs Who Teach
Not insightful... just flamebait... Are you also concerned about terrorist attacks on satellite launches or the X-Prize?
We're talking about an isolated platform in the middle of the south pacific ocean with nothing around it for hundreds of miles..... there have to be better targets for a terrorists with ICBMs at their disposal.
Get real... this is not political.... and it is virtually isolated from any sort of assault, whether it be from China or from Osama...
The only reason the towers were vulnerable is that they were within range of a very short sighted attack... which had no impact on our security, our national security... but only caused devastating damage to innocent families.
A fool throws a stone into a well and a thousand sages can not remove it.
The Spaceward Foundation is creating the Elevator:2010 program:
If we suddenly have 100 miles of superstrong material slamming down at hypersonic speed, it's going to be extremely bad
It'll be more like a 100-mile piece of paper fluttering to the ground. The ribbon will be extremely light. It needs to be, or it can't hold up its own weight. Why don't you go read the Space Elevator FAQ before displaying your ignorance?
Any sufficiently advanced libertarian utopia is indistinguishable from government.
I recall Arthur Clarke pitching the initial concept for a Space Elevator some time back, and revisited the idea in 3001 : The Final Odyssey - in which he depicted planet Earth having a fully functional ( four actually ) space elevator system; which facilitated a subset of human civilisation living in low earth orbits in reduced gravity - thus invoking presumed benefits of doing so.
Anywho. He spoke a couple years ago, subsequent to 3001's release on how at the time of writing, such a feat was nigh on impossible at this stage - as the materials to construct the 'elevator' were yet to be developed. Until now. The carbon molecule Buckminsterfullerene ( C60 ), also known as 'Fullerene', is supposedly strong enough to actually make such a concept a reality - which is in part the reason the space elevator was hurled back into the limelight of late.
I think its a fascinating idea - which until we develop propulsion systems beyond the primative scope of the 1,000+ year old firecracker concept, certainly seems a more elegant way for the species to venture into Space more regulary. Or, at the very least, be the catalyst for what could perhaps become the initial stepping stones to establishing a permanent presence in space which will hopefully later lead to space initiated launches.
What happened to the intermediate designs that don't provide all the benefit but also don't require two decimal orders of magnitude performance improvements? I didn't see anything in the
Brin's electromagnetically boosted tether design (Tank Farm Dynamo, 1983) would reduce the amount of delta-vee needed for orbit, at least allowing for cheaper shuttles. It's not much of a benefit, but we could build it today.
A rotating tether that dipped into the atmosphere would allow much greater safety margins and have a much less dangerous failure mode. You could practically rendezvous with one from an X-prize vehicle, and you wouldn't need to build a climber... just grab the tether, hold on for one rotation, and let go.
The big problem of course is that extra delta-vee isn't free, and the tether would lose altitude every time it's used (this is a problem for all tether designs, really). So, the throughput rate would be limited by the time needed to re-boost the tether between launches: using a high-efficiency low-thrust drive would be cheapest but require the longest "recharge" time.
Longer term, it would get a boost from de-orbiting mass from space: if you return a ship of the same mass to Earth at the same time as you boost one to orbit the net delta-vee is zero. If you have more ships going up than coming down, bring a nickel-iron asteroid into orbit and just feed a chunk of metal that weighs the same as the ship in from a higher orbit, it'd get de-orbited and released at 100km. Make it in an airfoil shape (a crude glider) and you can recover it... just deliver it to an asteroid-iron junkyard out in the middle of New Mexico or something.
THAT would make Rutan's barnstormer spacecraft a stage in developing a new industry, instead of a stunt.
The America / "The West" actually gets off its backside and builds it before China decides to.
Ripping an new rectum in the fabric of spacetime.
The text of Tank Farm Dynamo is online.
Something I never heared anybody about: Where does the kinetic energy come from that the cargo gains when ascending into orbit? Somehow the cargo needs to gain a huge amount of kinetic energy, because the top of the elevator moves several km/s faster then the bottom. If nothing compensates for this energy, the counter weight would gradually slow down and deorbit, so there must be some kind of propulsion in the counterweight, pushing it prograde whenever cargo ascends and pushing retrograde when cargo descends. Anybody got more info on this?
you're forgetting the big upside of the space elevator: the owners of the space elevator can drop shit on you from space! heavy things like big rocks, kitchen sinks, and 2000 pound gps-guided bombs. and let it be clear, there is no defence against kitchen sinks falling on you from space. we're talking afforable space based weapons platforms. the weapon of choice of the future may be raindrop-shaped ceramic projectiles with spent-uranium cores, raining unstoppably from above and smashing their way through tanks and into underground bunkers, or sinking an aircraft carrier battlegroup.
the military of the country that builds this wonderous weapons platform will let see to the safety of the tether, you can bet on that.
I wouldn't worry about being killed by a carbon fiber making meteoric reentry. It wouldn't be like the disaster in the Mars trilogy, or even like shadow square wire... by the time it hits it'll be more like laser toner, the stuff is strong in tension but it burns quite nicely: Nanotube Explosions
While Arthur C. Clarke certainly popularized the idea of a space elevator in his science fiction novel "The Fountains of Paradise", the original concept is credited to the Russian engineer Yuri Artsutanov, who published it in 1960. See, for example, here
Ubi dubium ibi libertas: Where there is doubt, there is freedom.
Harsh? Yeah.
--- Ban humanity.
It is not necessary to use a heavy mass at geosynchronous orbet. Instead, make the cable twice as long, and put the center of mass OF THE CABLE at geosynchronous orbit. That way you get extra-orbital launching basically for free.
Did you mount a military-grade, variable-focus MASER on an unlicensed artificial intelligence?
It's easier than most people think, you don't need to capture an asteroid. You send up a small counterweight along with the initial spool of cable, and as the first cable unspools downward from geosync, the counterweight moves up. You end up with the first strand of cable fully extended with a small counterweight, just enough to hold itself and a small payload. From there it's trivial, to add more cable you carry it up the initial cable, and to add more counterweight you have the cable-laying climbers go all the way to the end and become part of the counterweight, and/or send separate climbers to carry up the counterweight.
Current proposals for implementation of the Hans Moravec's original design rely on a hypersonic air-breather of advanced aerodynamic design like the Boeing DF-9 (that exists only on paper).
Can /. readers think of anything likely come along in the near future that could take
paylods to 100km and mach 12?
Probably the same thing that is driving the bureaucrats to make all this noise about space elevators now.
A key to the Rotovator(tm) is getting hub mass in place to keep it out of the atmosphere while it picks up mass from 100km@mach12 -- but that mass can be any old space junk -- at least at the hub where it counts the most for high strength materials like carbon nanotubes. However, you can do a Rotovator(tm) with off-the-shelf commercially available fibers and still have a factor of 2.
Nice thing about Rotovators(tm) is that they can be built with much lower capitaliztion over a much shorter period of time using existing commercial materials. All you need is a bunch of mass orbiting near earth, some quite-doable tethers, and sufficient manuverability and speed in the atmospheric leg to hook up with the tether as it reaches the nadir.
Seastead this.
And what if the tether breaks and drops on Earth
1. Everything above the cut would stay in orbit. Everything below the cut would fall to Earth. The base will be on the West side of the Atlantic Ocean and will therefore have hundreds of miles of water to its East. Most of the dangerous things that can cut it are in LEO, which is less than "hundreds of miles" away. So more than likely everything that falls to Earth will fall into the Ocean.
2. Just because the cable has high tensile strength that doesn't mean it is indestructible. You can bind a person's hands with speaker wire and no matter how strong the person is, they wont be able to break free. But that doesn't mean the wire is magically indestructible. It's just wire.
3. In the current issue of Discover Magazine, the concept they write about calls for a cable a few feet across, but only as thick as a sheet of paper. I don't know why so many people assume we are talking about an elevator to lift humans. The first several incarnations will be for light cargo only. Anyway, a cable as thin as a sheet of paper will mostly burn up as it falls through the atmosphere. If any of it survives, it will be shattered into pieces (not together as a whole cable) and will have the same terminal velocity as a sheet of paper. It will just flutter to the ground without hurting anyone. If you are lucky enough to live in the debris path, you can collect the stuff up and sell it on ebay.
So many people make the mistake of assuming that there is some horrible danger that only they will recognize. As if hundreds of scientists around the world are diligently studying this and then Frans Faase of slashdot comes along and says, "what about this problem here?" And all those scientists will just throw up their hands and say "oh god, we all have PhDs but we didn't think of that - we aren't as smart as Frans." Right.
Only if your phallus is less than one millimeter in diameter and stretches for miles.
Oper on the Nightstar
Don't forget the really big rocket you need to attach to the kitchen sink in order to kill nearly all of its momentum so it doesn't just sit there in orbit with you making you look really foolish.
Nothing.
It's a ribbon. It's literally nearly equal to the weight of an equal width of Saran Wrap.
How much unrolled saran wrap do you have to drop on someone before it hurts them?
How many buildings will be devastated by having something that flimsy dropped on them?
The devastating space elevator fall is bad science fiction. If it breaks, stuff above will stay in orbit, and stuff below the break will fall harmlessly.