Inflatable Space Elevator to 20 kilometers
August 18, 2015 9:06 AM   Subscribe

Wild Inflatable Space Elevator Idea Could Lift People 12 Miles Up

The space elevator concept has long been a dream of space enthusiasts. Unfortunately, the technology is also held to be unfeasible because no known material can support itself at such a height.

Now, a Canadian company, Thoth Technology*, has been awarded US and Canadian patents for a space elevator design using existing technologies. The design avoids the material strength problem by proposing a flexible free-standing structure 'only' 20km tall.

Announced today in the US Patent Office Gazette, the freestanding space tower would be pneumatically pressurized and actively-guided over its base. It would stand more than 20 times the height of current tall structures and be used for wind-energy generation, communications and tourism. The tower would be topped by a commercial spacecraft launch pad and runway.

SpaceX is testing self-landing rockets, and has made several attempts at landing a rocket on a sea barge, in a move that SpaceX says will eventually decrease launch costs.

“Landing on a barge at sea level is a great demonstration, but landing at 12 miles above sea level will make space flight more like taking a passenger jet.”
-- Thoth CEO Caroline Roberts

US Patent text
A space elevator tower . . . comprising: a pneumatically pressurized structure formed from flexible sheet material . . . divided into a plurality of segments along a length of the space elevator tower, each of said plurality of segments containing a plurality of cells defining a core, and a plurality of stabilization devices distributed along the length of the space elevator tower; wherein the plurality of cells are pressurized with a gas to support the pneumatically pressurized structure; and wherein said plurality of stabilization devices is configured to provide active stabilization of the space elevator tower using a harmonic control strategy.
Why we'll probably never build a space elevator
  • No Known Material Will Be Strong Enough
  • It Would Be Susceptible to Dangerous Vibrations
  • Climbers Will Create Too Much Wobble
  • Satellites and Space Junk will wreck it
  • Social and Environmental Risks aplenty
. . . But it would work on the Moon

Should we give up on the dream of space elevators?
This is extremely complicated. I don't think it's really realistic to have a space elevator . . . It's not the thing that I think makes sense right now. But if somebody can prove me wrong that'd be great.”
-- Elon Musk
“I love the outrageousness of the idea. . . . [But] even if we could overcome the considerable engineering challenges involved in building this thing, it paints a rather terrifying picture of a giant cheese wire scything through space taking out space vehicles and being itself hit by all the space debris already up there.”
-- Kevin Fong, Centre for Altitude, Space and Extreme environment medicine at University College London

-------------------------------------
* I'd love to be able to say, 'Thoth was the Egyptian god of x', but Thoth's place in the pantheon is so complicated, I'll just recommend you read the Wiccuhpeedia page if you're interested. One [among several] manifestations of Thoth depicted him as a human with an ibis head, and you'll see the company uses an ibis in its branding.
posted by Herodios (70 comments total) 7 users marked this as a favorite
 
And by "people" we mean Elon Musk and Jeff Bezos.
posted by Naberius at 9:11 AM on August 18, 2015 [1 favorite]


Oh Pembroke. My home County: Lots of dreamers, very little money.
posted by Popular Ethics at 9:16 AM on August 18, 2015


It seems to be a tower made of kevlar balloons, quite possibly hydrogen and/or helium ones. So it's somewhere between a classic ribbon elevator design and an aerostat, a tethered blimp. High altitude balloons get to 20 miles+ altitude now, so we know that part works.

That doesn't sound impossible, only wildly impractical. Lots of big projects sound crazy at first, but this is the first one I've seen that didn't seem impossible.
posted by bonehead at 9:18 AM on August 18, 2015 [2 favorites]


My first though is, what is it filled with? 20 cubic miles of hydrogen seems like a bad idea, and does that much helium even exist on Earth?
posted by T.D. Strange at 9:24 AM on August 18, 2015 [1 favorite]


Yeah, the patent specifies 'a gas' and then 'hydrogen' or 'helium.'

Ha.
posted by mrdaneri at 9:32 AM on August 18, 2015 [1 favorite]


That doesn't sound impossible, only wildly impractical.

Wind is a thing.
posted by Sys Rq at 9:32 AM on August 18, 2015 [1 favorite]


This might be interesting for getting access to the upper atmosphere, but it does pretty much nothing when it comes to putting things in orbit. Space isn't high, space is fast.

The reason a classical space elevator is so attractive is because as you're making the long climb to geostationary orbit, you're getting the orbital speed for free.
posted by Sokka shot first at 9:34 AM on August 18, 2015 [20 favorites]


Wind is a thing.

It has "active stabilization", you know, with umm...stabilizers.
posted by T.D. Strange at 9:35 AM on August 18, 2015 [3 favorites]


You could use Neon and make it big and glowy, or water vapour, and make it drippy, or Methane or Ammonia and make it smelly.

Or very very theoretically you could use some sort of sealed aerographite structure supporting a hard vacuum, but I don't think anyone has got that to work.
posted by Just this guy, y'know at 9:36 AM on August 18, 2015


They mention 'gyroscopes.' Ya' know. Hundreds of thousands of them, needing repair, maintenance and carrying catastrophic consequences upon failure. NBD. Clearly everyone involved has thought everything through.
posted by mrdaneri at 9:40 AM on August 18, 2015 [1 favorite]


The invention claimed is:

1. A space elevator tower for location on a planetary surface.....
...
18. The space elevator tower of claim 1, wherein the gas is air.
19. The space elevator tower claim 1, wherein the gas is not.
20. The space elevator tower of claim 1, wherein the gas is hydrogen.
21. The space elevator tower of claim 1, wherein the gas is helium.

So they're patenting filling it with air first of all, then with not air then specifically (and unnecessarily, hydrogen or helium)

Actually, thinking about it, you have a bunch of surface area there, you might be able to just paint it black and use that to heat up the air inside. That would give you lift.
posted by Just this guy, y'know at 9:41 AM on August 18, 2015


This is a silly idea that's wildly impractical and jesus christ I hope it works.
posted by Brandon Blatcher at 9:45 AM on August 18, 2015 [10 favorites]


That would give you lift.

So might one of these jobbies. Stick the balloon structure on top of a solar updraft tower.
posted by bonehead at 9:46 AM on August 18, 2015


Sokka shot first, you don't get the velocity for free. The energy has to come from somewhere. I'm not really great at physics, but I imagine that if you had like, a very rigid space elevator that didn't bend much, you'd be getting orbital velocity by slowing down the rotation of the Earth. If the elevator is flexible, then you will probably instead be sapping the orbital velocity of the elevator itself, which will make it list over. You'd need something like a bunch of thrusters at the top of the elevator to add that energy back into the elevator system as you sent payloads up it. Now ideally, you could use ion drives with really good specific impulse, and power them either via power sent from the ground, or generated in orbit via solar panels or something. Alternatively, you could try to carefully balance the mass differential of payloads going up, which will gain energy from the system, with payloads going down which will lose energy.
posted by rustcrumb at 9:47 AM on August 18, 2015 [1 favorite]


This is a perfect example of why the patent system is stupid. They have solved none of the engineering issues involved - the patent is best seen as a bad science fiction story. But if someone does ever spend the hundreds of thousands of hours of work and billions of dollars to actually create it, these losers will expect to collect all the profits.
posted by lupus_yonderboy at 9:55 AM on August 18, 2015 [21 favorites]


Wild Inflatable Space Elevator appeared!
It uses Amaze!
Amaze is ineffective.
posted by Splunge at 9:57 AM on August 18, 2015 [8 favorites]


Sokka shot first nails the big problem. Space isn't high, space is fast.

But there are a couple of advantages to starting 20 miles up. You're above the clouds, so no worries about a storm messing with your launch window. You're also well above a good part of the atmosphere -- basically, you're looking at an ambient pressure of 10 millibars at that altitude. That means you can use engines designed for vacuum, rather than sea level, and most importantly, you're not fighting through that atmosphere! So, rather than having to launch basically vertically to get out of the thick part of the atmosphere as fast as possible, you can get right into the gravity turn and start building horizontal velocity. You can't ignore aerodynamic drag -- when you start rolling past Mach 5, even fractional millibar pressures mean you're dealing with real friction and drag, but it's not the wall that ground based boosters have to fly through.

You still need to get to orbital velocity, but it will be easier starting up there. The hard part, of course, will be hauling the booster up there, but that's much easier on a elevator than on a rocket. It will result in a much different design -- a booster that basically a large second stage and a final shaping stage, rather than the big "get out of the atmosphere stage" and a second stage we have now.

SSTO from the top of that tower also looks much more probable, but I've only quickly run the math and haven't really checked it thoroughly -- in particular, I haven't run *any* atmospheric drag work and that's always a mistake when you say "Oh, yeah, that'll work."
posted by eriko at 10:01 AM on August 18, 2015 [5 favorites]


you don't get the velocity for free. The energy has to come from somewhere. I'm not really great at physics, but I imagine that if you had like, a very rigid space elevator that didn't bend much, you'd be getting orbital velocity by slowing down the rotation of the Earth.

IANAP, but I think the traditional space elevator is a long rope with a weight on the far end, twice as far out as you want to go. It is held taut by centrifugal* force, like the earth is swinging around a dead cat on a string. The elevator car climbs up the rope. The win is that you can provide power (e.g., electricity) to the car as it goes up via the rope -- you don't have to carry all the propellant on board, burn it and throw the exhaust out the back.

As for conservation of energy, I think you're correct that you're stealing energy from the rotation of the earth. That's OK, there's plenty there, we'll never run out.**

* Yeah, I know, centripetal acceleration.
** And 640k is enough for anybody.
posted by spacewrench at 10:02 AM on August 18, 2015 [5 favorites]


So you're saying it's a 20 km version of this guy?
posted by Existential Dread at 10:04 AM on August 18, 2015 [3 favorites]


But if someone does ever spend the hundreds of thousands of hours of work and billions of dollars to actually create it, these losers will expect to collect all the profits.

Most likely they're hoping to cash in on a long play and sell this crap patent to Space X or someone else who actually does the work. Patent trolls gonna troll.
posted by T.D. Strange at 10:04 AM on August 18, 2015


the patent system is stupid

This would have been an ideal time for the examiner to request a demonstration. They have specific rules for perpetual motion machines and, I think, cancer cures, but they can ask in other situations:
With the exception of cases involving perpetualmotion, a model is not ordinarily required by theOffice to demonstrate the operability of a device. Ifoperability of a device is questioned, the applicantmust establish it to the satisfaction of the examiner,but he or she may choose his or her own way of so doing.

MPEP 608.03
I think this patent, if ever asserted, would run into serious problems with inadequate written description -- they failed to describe the invention in a way that allows a person having ordinary skill in the art to make and use the invention.
posted by spacewrench at 10:07 AM on August 18, 2015 [10 favorites]


Agreeing with spacewrench; I'm surprised the examiners actually allowed this patent to issue, because it obviously has not been reduced to practice. I would imagine that this patent has essentially no value, because once you get to the point of actually trying to build such a thing, there will likely be a whole host of new innovations required to actually get it off the ground, leading to a whole portfolio of patents.

The claims are extremely broad, but engineering around them is extremely likely to happen, if this ever gets off the ground.

rimshot
posted by Existential Dread at 10:15 AM on August 18, 2015 [1 favorite]


Okay cool, but it's more of a wild inflatable lower stratosphere elevator idea.
posted by sfenders at 10:16 AM on August 18, 2015 [2 favorites]


As for conservation of energy, I think you're correct that you're stealing energy from the rotation of the earth.

Conservation of angular momentum means that there is basically no way to steal energy from the Earth's rotation without ejecting stuff into space or permanently redistributing the Earth's mass. As the elevator goes up the Earth will slow down a bit, but when the elevator goes back down the Earth will regain that speed.
posted by Pyry at 10:24 AM on August 18, 2015 [2 favorites]


The way I understand it, patenting something means that you get exclusive rights to the object of the patent for 20 years, in exchange for the documentation. Since I doubt we'll see this implemented in the next 20 years, this may just be a good way of making sure that when its time comes, if ever, it can't be re-patented or patent-trolled.
posted by Blackanvil at 10:24 AM on August 18, 2015 [1 favorite]


I haven't run *any* atmospheric drag work and that's always a mistake when you say "Oh, yeah, that'll work."


Nah, that (usually) works fine in KSP.
posted by Brandon Blatcher at 10:26 AM on August 18, 2015 [7 favorites]


It is available in several of the links, but since no one else will just say it, the patent number is 9,085,897. Now you can find the full document, including diagrams, on your platform of choice. (Google Patents is pretty good.)

Also I feel the need to offer a qualified defense of the patent system here; those claims where the patent recites "a gas," (cl. 1 ) and then "hydrogen," (cl. 20) and then "helium" (cl. 21) - that is called "dependent claiming." The idea is, you write the general, "independent" claim as broadly as you can get away with, and then in case the more general case is found, down the road, to be obvious, or to be disclosed in the prior art, or whatever, you still have the narrower, more specific embodiment as a backup. So this is not a case of "he said gas, then he said helium, har har that's redundant, what a moron." The "redundancy," i.e., specifying more narrowly within the broader category already stated, is the entire point. See MPEP section 608.01(n).

There's no excuse for claim 19 though, ending in "the gas is not." Definitely sloppy drafting and sloppy review there.
posted by Joey Buttafoucault at 10:34 AM on August 18, 2015 [2 favorites]


The way I understand it, patenting something means that you get exclusive rights to the object of the patent for 20 years, in exchange for the documentation. Since I doubt we'll see this implemented in the next 20 years, this may just be a good way of making sure that when its time comes, if ever, it can't be re-patented or patent-trolled.

Technically, you get the right to sue anyone who practices the idea, provided you pay the patent office the issues fees and maintenance fees at 3.5, 7, and 12.5 years. A more cost-effective approach would be to write this up and publish it; anything that has been previously published is no longer eligible for patentability. If you have no intention of actually commercializing the technology, the patent has no value and is just sunk costs. Likewise, if you have no intention of suing infringers, the patent has no value.
posted by Existential Dread at 10:37 AM on August 18, 2015


You could use Neon and make it big and glowy, or water vapour, and make it drippy, or Methane or Ammonia and make it smelly.

No, methane is odorless. You would use methane to make it big and flammable.

Which for me is a key feature in a massive sky structure.
posted by nickmark at 10:39 AM on August 18, 2015 [6 favorites]


A more cost-effective approach would be to write this up and publish it

In theory, that would work to create prior art that the patent office could find to reject subsequent patent applications, but in practice, most of the prior art the examiners find and use is in patents and patent applications. For the relatively small cost of filing a patent, they've put the information in exactly the place a future examiner will look. They must think it's worth it (and frankly, I would agree, even if you ignore the VC-attracting buzz these guys will get from having obtained a patent.)
posted by spacewrench at 10:42 AM on August 18, 2015


Conservation of angular momentum means that there is basically no way to steal energy from the Earth's rotation without ejecting stuff into space

But that's the whole point of a space elevator: to take some mass off earth (say, mass that looks suspiciously like a spacecraft) and fling it into space. Sure, the elevator car comes back down, but the spacecraft is going to carry some of the earth's angular momentum energy to ... Mars, maybe?

Of course, when the craft lands there, it will transfer that energy to Mars, but if it can do it in a controlled manner, people could hitch a ride pretty safely!
posted by spacewrench at 10:44 AM on August 18, 2015 [1 favorite]



Conservation of angular momentum means that there is basically no way to steal energy from the Earth's rotation without ejecting stuff into space or permanently redistributing the Earth's mass. As the elevator goes up the Earth will slow down a bit, but when the elevator goes back down the Earth will regain that speed.

Ah, cool, I wasn't clear on that part. The implication is that mass that doesn't come back down will not speed the Earth back up, so you need to balance any spacecraft leaving for Mars with spacecraft returning from Mars, or else you get a slight slowing (or, more entertainingly, just keep on receiving rocks from the Belt and keep on sending them down to Earth to get a continual accelerating).
posted by Mogur at 10:45 AM on August 18, 2015


For the relatively small cost of filing a patent, they've put the information in exactly the place a future examiner will look. They must think it's worth it (and frankly, I would agree, even if you ignore the VC-attracting buzz these guys will get from having obtained a patent.)

I agree, if your goal is to attract VC funding, this is a great way to do it.

If you want to establish prior art, a patent application would be sufficient; no need to pay the issue fees once the patent application is published.
posted by Existential Dread at 10:47 AM on August 18, 2015


What could possibly go wrong with these here giant, wax, wings?
posted by Oyéah at 11:06 AM on August 18, 2015 [2 favorites]


It's my belief that they are entirely in earnest:

A free-standing space elevator structure: a practical alternative to the space tether, Acta Astronautica v. 65, Issues 3–4, August–September 2009, Pages 365–375, B. M. Quine (a,b), R. K. Seth (b) and Z. H. Zhua (a) Department of Earth and Space Science and Engineering, York University
(b) Department of Physics and Astronomy, York University

See also:
J.Storr Hall's Space Pier (a hybrid space-launch tower concept), from his book Nanofuture: What's Next for Nanotechnology (2005).
 
posted by Herodios at 11:10 AM on August 18, 2015 [1 favorite]


Nobody seems to see the real danger here. The year is 2050. A 12 mile high inflatable tower, um, towers above the landscape. A monument to human genius and technological prowess. All revel in its glory. The future is ours to claim.

A year later the tower is pierced by a harmless prankster.

Almost instantly a massive fart sound begins to emanate from the structure. It will last for 7 days. Within a 100 mile radius of the deflating tower all structures are reduced to rubble within seconds. Within a 500 mile radius the ear drums of all living beings are ruptured rendering them permanently deaf. They are the lucky ones. A quarter of humanity dies over the course of the next 2 days from the direct impact of prolonged and uninterrupted laughter on pre-existing conditions. They drop like flies as they succumb to aneurysms, heart attacks and exhaustion. The rest continue to laugh. And laugh. And laugh. By day 5 the remaining three quarters of humanity with undamaged hearing have descended into utter insanity. Chaos reigns.
posted by Hairy Lobster at 11:14 AM on August 18, 2015 [9 favorites]


If they can solve the structural engineering problems, it would be self-powering — perhaps even energetically favorable. Imagine a structure that pulls solar panels above the clouds, and raises wind turbines to where it is windiest...
posted by a lungful of dragon at 11:16 AM on August 18, 2015 [1 favorite]


A 12 mile high inflatable tower, um, towers above the landscape.

Farmer [shakes fist]
posted by bonobothegreat at 11:33 AM on August 18, 2015 [2 favorites]


Conservation of angular momentum means that there is basically no way to steal energy from the Earth's rotation without ejecting stuff into space or permanently redistributing the Earth's mass. As the elevator goes up the Earth will slow down a bit, but when the elevator goes back down the Earth will regain that speed.

Fun fact: unless its exhaust escapes the gravitational pull of the Earth, a rocket-powered vehicle launched from the ground has the same effect on the total angular momentum of the Earth as a vehicle launched from a space elevator into a similar (prograde, equatorial) orbit.
posted by The Tensor at 11:47 AM on August 18, 2015 [1 favorite]


Imagine a structure that pulls solar panels above the clouds, and raises wind turbines to where it is windiest...

Disrupting bird migrations and weather patterns unpredictably....
posted by Existential Dread at 12:01 PM on August 18, 2015


Mogur, isn't this one part of the basic plot points in Heinlein's _The Moon Is a Harsh Mistress_? What goes up must come down, what goes down must come up, because otherwise we're mucking up the respective orbits of Earth and Moon, oh noes?
posted by elizilla at 12:02 PM on August 18, 2015


a lungful of dragon -- this tower concept actually crosses into the jet stream with the proposed platform at 20km sitting in the jet stream. Wind turbines wound be amazing assuming the structure doesn't get torn apart by 160km/h winds at altitude
posted by nathan_teske at 12:23 PM on August 18, 2015


That's actually a feral inflatable space elevator.
posted by srboisvert at 12:43 PM on August 18, 2015


The Moon is a Harsh mistress is concerned with loss of water and organics; something the moon is in short supply of. The fact that moon-earth launches are effecting rotation isn't mentioned.
posted by Mitheral at 12:49 PM on August 18, 2015


Mrdaneri - gyroscopes are just chips now (albeit ones with tiny flexible bars etched out of the silicon), costing cents and lasting forever. Your phone probably has one.

Of all the problems this proposal has, gyros aren't one of them.
posted by Devonian at 12:59 PM on August 18, 2015 [3 favorites]


gyroscopes are just chips now

And it's a good thing too, otherwise to keep them all spinning we'd have to spin the earth in the opposite direction, just a little.
posted by sfenders at 1:27 PM on August 18, 2015 [1 favorite]


I think wind forces would cause a light breeze to snap this thing off its moorings, unless they are using unobtanium cables.
posted by humanfont at 1:51 PM on August 18, 2015 [1 favorite]


Devonian: "Mrdaneri - gyroscopes are just chips now (albeit ones with tiny flexible bars etched out of the silicon), costing cents and lasting forever. Your phone probably has one. "

Fascinating.
posted by Splunge at 1:56 PM on August 18, 2015 [6 favorites]




Further, while the present invention has been described in terms of a structure that is largely or wholly supported by internal pneumatic pressure..

Seems like the lower sections would have to be under some fairly ludicrous amount of pressure to support this 20km column of stuff. Is there any way to see the full text of this thing without paying? I'm very curious if they worked it out.
posted by Kikujiro's Summer at 2:20 PM on August 18, 2015


a lungful of dragon -- this tower concept actually crosses into the jet stream with the proposed platform at 20km sitting in the jet stream. Wind turbines wound be amazing assuming the structure doesn't get torn apart by 160km/h winds at altitude

I'm almost thinking that the space tourism aspect is almost tangential. Any engineer who can solve the structural problems could take a good stab at entirely solving the world's energy problems — just put up a tower and pull down free, non-fossil-fuel, non-nuclear, renewable electricity. The space stuff would be the punctuation on the writing on the icing on the cake.
posted by a lungful of dragon at 2:23 PM on August 18, 2015


Great pic, Splunge. One to add to my file of evidence that modern electronics is actually created by tribes from the Nasca Plain...
posted by Devonian at 2:42 PM on August 18, 2015


It's never gonna happen 'coz the first thing people would notice is the absence of any curvature when they look down at the Earth. And I'm not joking btw - we live on a flat Earth. You have been lied to... Photos of the Earth from space are either photos of high-res paintings or CGI. What is more likely - that we are glued to a ball that is hurtling through space at 1000 miles an hour by a force we can't see or even feel, or that we live on a flat plane? Look at a ship on the horizon with a telescope and you see the whole ship, not just the mast. I could go on... There are clues...
posted by Monkeymoo at 2:50 PM on August 18, 2015 [1 favorite]



Is there any way to see the full text of this thing without paying? I'm very curious if they worked it out.

The patent full text

The scholarly article full text

Both linked above. Neither is behind a paywall.
 
posted by Herodios at 2:55 PM on August 18, 2015


The only way I could see this being useful is as a platform for scramjet launches, and then only if scramjet's problems are worked out. I'm not sure whether this gets you anything beyond what a floating lighter-than-air runway might get you, which seems like it'd have fewer engineering challenges other than station-keeping.
posted by BrotherCaine at 3:13 PM on August 18, 2015


rustcrumb : "Alternatively, you could try to carefully balance the mass differential of payloads going up, which will gain energy from the system, with payloads going down which will lose energy."

It might not effect the total energy of the elevator itself (or the orbital energy of the Earth) but you certainly would want to balance the weight of elevator cars going up with other elevator cars going down. That way you're using gravity to do some of the lifting work for you.



spacewrench: "IANAP, but I think the traditional space elevator is a long rope with a weight on the far end, twice as far out as you want to go. It is held taut by centrifugal* force, like the earth is swinging around a dead cat on a string."

Yeah. And just putting the asteroid counterweight in geostationary orbit would cost as much energy as constructing the elevator. Then you start on the counterweight and build down towards the Earth. The Earth end of the elevator doesn't have to be attached to the planet at all. You could use some kind of vehicle to reach it, or embed the end in a large vehicle. That would give you the option of moving the end around a bit to counter vibrations.

Most space elevator schemes count on being able to use materials and energy harvested from space, because you don't want to haul all that stuff up from Earth's surface with rockets. So this is usually considered a medium to far future kind of idea. Something that we might be able to do someday when we have some serious industry set up beyond the Earth.
posted by Kevin Street at 3:32 PM on August 18, 2015


The Fountains of Paradise.

The Fountains of Paradise is a Hugo[1] and Nebula[2] Award–winning 1979 novel by Arthur C. Clarke. Set in the 22nd century, it describes the construction of a space elevator. This "orbital tower" is a giant structure rising from the ground and linking with a satellite in geostationary orbit at the height of approximately 36,000 kilometers (approx. 22,300 miles). Such a structure would be used to raise payloads to orbit without having to use rockets, making it much more cost effective.
posted by Splunge at 3:42 PM on August 18, 2015


No, methane is odorless. You would use methane to make it big and flammable.

Which for me is a key feature in a massive sky structure.


It's also renewable!
posted by Ray Walston, Luck Dragon at 4:00 PM on August 18, 2015


Physicist David Brin's Uplift novels, beginning with Sundiver, alluded to mankind's development of two equatorial towers in this vein, called the "Vanilla Needle" (Ecuador) and "Chocolate Needle," (Kenya) apparently owing to some popular crops in the vicinity. They used them as ballooning towers-- giant balloons lifted spacecraft above the atmosphere for high-altitude launch. The trick here was that the tower was pressurized to the top, so balloons worked up there as well as they do down here. Then the rocket or spaceship was offloaded and launched, while the balloon was allowed to descend back down.
posted by Sunburnt at 4:27 PM on August 18, 2015 [1 favorite]


So in that idea you have inflatables inside a tower instead of an inflatable tower. Intriguing.
posted by Kevin Street at 4:35 PM on August 18, 2015


The York University professor behind the story was interviewed tonight on CBC Radio's As it Happens (starts at 20:15). He makes it sound a bit more credible, but it's still a wacky idea - if you can build a 20km tall inflateable tower, there are lots of neat uses that are less difficult than spaceport!

This is the umpteenth time I've seen an FPP from Mefi appear on AIH the same day. I have a hunch their producers monitor this site for content. Hi guys! Love the show! :)
posted by Popular Ethics at 6:23 PM on August 18, 2015


Um. So I'll raise my ignorant hand here...

20km/12 mi is around 63,000 feet above sea level.

That's not exactly space. In fact, in matters where this sort of thing...matters...it's not even close.

Right?
posted by Thistledown at 6:24 PM on August 18, 2015


By my quick read of their paper 20km is the the point where there wpuld be a substantial fuel savings by reduced drag. The authors suggest higher towers would be possible using the same technique.
posted by humanfont at 6:39 PM on August 18, 2015


It's not space, no. That officially starts at 62km or so.

Doesn't matter though, being able to launch rockets from 12mi would be very useful.
posted by Brandon Blatcher at 6:39 PM on August 18, 2015


Depends on the proplusion of rocket.
posted by clavdivs at 7:36 PM on August 18, 2015


My guess is that 20km is near the point where fuel savings by building taller start to diminish rapidly, since you're already above such a large fraction of the mass of the atmosphere at that height. Rockets launched to some particular orbit are estimated to be 26% more efficient at 20km; maybe if they made it 200km it'd be 30% or a little more in fuel savings. Perhaps worth building just for that, but it's not exactly "space elevator" levels of awesome. An actual space elevator would reduce launch costs to GEO by more than an order of magnitude.

A more compelling motive to build a floaty sky tower might be to give some ambitious theocracy / plutocracy / dynamic emerging economy the bragging rights to having the tallest tower in the world by a large margin and for a good long time. If these guys look like they can actually build it, I expect they'll be hired or kidnapped away any day now to do so.
posted by sfenders at 8:28 PM on August 18, 2015


The whole structure will be kept rigid with passion fruit and yohimbe bark. Then won't the space plane take off make the whole business twing like a coiled metal doorstop? Is the deck of the elevator about the size of an aircraft carrier? This just sounds like a really big, expensive, exploding, problem that is basically a concept toy elite dreamer contractors, will make us afford, while making it seem we are saving energy and money.

The really scary stories today are the tiny man made brain, on a collision course with that headless robot they have tromping around in the woods, out front of its power cord. I can see that coming.
posted by Oyéah at 9:51 PM on August 18, 2015


All eyes see the figure of the wizard
As he climbs to the top of the world
posted by flabdablet at 6:07 AM on August 19, 2015


They mention 'gyroscopes.' Ya' know. Hundreds of thousands of them, needing repair, maintenance and carrying catastrophic consequences upon failure. NBD. Clearly everyone involved has thought everything through.
posted by mrdaneri at 12:40 PM on August 18


I'm willing to bet they put more thought and effort into it than you did, Mr. Internet Expert. Really? This system won't work because we can't make reliable gyroscopes, and/or don't understand functional redundancy?

Sigh. People who get things done NEVER listen to people who comment on these forums. They couldn't. The whole big-lever-move-things invention would have been ridiculed to death before the log was felled.
posted by IAmBroom at 11:08 AM on August 20, 2015


Here's what this is, folks: an idea to spark discussions. Even if space elevators are never a thing, they might be, and if they could be, we won't get there without lots and lots of ideas.

How many unworkable space ship ideas were proposed before Sputnik?
posted by IAmBroom at 11:09 AM on August 20, 2015


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