Inflatable space elevator gets a lift

Tom Kalbfus · 2015-08-05 17:39:01

Inflatable space elevator gets a lift

CNET
CNET

Eric MackAugust 5, 2015

This article, Inflatable space elevator gets a lift, originally appeared onCNET.com.
6b67bb3561e648efdfa2b45236b1e229
Top floor, please. Thoth Technologies

Technically speaking, getting to space hasn't become any easier over the past half century or so. It still requires using huge rockets to create a massive enough amount of force to push a payload beyond the grip of Earth's gravity.

Enter the concept of the space elevator, which uses much simpler gravity-defying technologies to access space.

So far, most space elevator concepts have been the stuff of sci-fi, and any plans to actually build one have remained on the rather distant horizon. But "push button" access to space took a step toward reality in late July when the US Patent and Trademark Office granted apatent to a Canadian company for its invention of an inflatable space elevator tower.

Thoth Technology, based in Pembroke, Ontario, devised a tower design using pressurized segments that reach up to 20 kilometers (12.4 miles) into the stratosphere where a platform could be constructed for purposes of communications, tourism or as a launch platform for reaching space. Unlike blasting off from near sea level, as most space launches do now, getting into orbit or beyond from the top of a space elevator more than 20 times taller than the highest structures on Earth would be more like an aircraft takeoff.

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"Astronauts would ascend to 20 km by electrical elevator. From the top of the tower, space planes will launch in a single stage to orbit, returning to the top of the tower for refueling and reflight," Brendan Quine, the inventor, said in a statement.

This elevator is far less ambitious than others we've reported on like plans from Japan's Obayashi Coroporation, which hopes to extend aspace elevator a quarter of the way to the moon by 2050.

The company sees space elevators leading to a new era of space travel when paired with other new technologies like self-landing rockets of the kind that SpaceX is working on.

Getting to that point will involve some new innovations that this patent doesn't really address, however. The invention here is focused on the construction of the tower itself, but how to construct and maintain a strong, reliable elevator cable 12 miles long is the real challenge in the space elevator universe. In fact, it's the focus of a space elevator conference taking place later this month.

The patent does suggest "the mechanism for elevating and lowering cars may be provided by frictional contact, at least one winch mechanism located along the length of the elevator core structure, or by inductive means" but each of those mechanisms would still need to be invented or customized to this design.

For now, we're stuck having to ride fire to space, but the "slow space" movement is well under way and the invention of the new genre of space elevator music can't be far behind.

RGClark · 2015-08-06 09:22:21

Thanks. Pretty cool.

Bob Clark

Tom Kalbfus · 2015-08-11 17:24:28

What if we built one on Venus that was 50 km tall? I think the best place to do that would be at the North or South Poles of Venus, that way the wind is not super-rotating as fast, and you also eliminate the problem of those very long nights and days on Venus due to the planet's slow rotation. You build a dome on top of the tower where humans live and its anchored to the ground and stays in place at a fixed geographic location.

6b67bb3561e648efdfa2b45236b1e229
Imagine this on Venus, instead of a runway on top, you have a dome and perhaps a landing pad for Venusian shuttles.

SpaceNut · 2015-08-11 19:29:18

I could see this being possible on Mars if we could get enough air/gasses to fill each chamber to make it rise up. The most volume of air to volume will be in the base of the structure with the top having the least.

Tom Kalbfus · 2015-08-12 18:28:25

Getting off of Mars is not really a big problem, getting off of Earth is Towers on Mars could probably be built three times as high, which in this case would be 60 kilometers. What could these towers be used for? I have a good idea, what if they were used to provide additional light and heat for the Martian surface, if we were to simply paint the towers black so they absorb more sunlight, or perhaps even cover them with solar panels, the extra energy collected could be used to warm the planet's surface, if you don't mind a planet that is studded with these towers all over its surface. You effectively increase the absorptive surface of Mars, making Mars appear darker in our night skies, Artificial light at the ground level would make it more habitable, roofing would be a trivial problem at this point, you just compress Mars atmosphere under this roof to 1 atmosphere, alter the mixture to make it breathable. Probably additional mining activity will liberate more carbon-dioxide. People would live in these towers much as I described for Venus in my other post, and Mars will become another city planet with way more living space than we'll possible need for a long time. We could do something similar for the Moon by the way, but in that case the towers would be 120 km tall! the shadows cast on the Moons surface would allow us to provide artificial lighting on the ground level suitable for humans on a 24 hour cycle. A roof would contain a breathable atmosphere under glass.

RobertDyck · 2015-08-12 19:49:37

I see Thoth is a going concern. Good for them. And Caroline is still with Brendan. Good for them. I met them at the 3rd Canadian Space Exploration Workshop, hosted by the Canadian Space Agency. I was trying to network. It started with a cocktail mixer. I felt awkward and was worried I wouldn't fit in. Then met a couple members of the Canadian chapter of the Mars Society; we knew each other. One guy with a Ph.D. didn't have his paperwork for the workshop, I was better prepared. Ok, so I fit in. I tried to screw up the guts to talk to new people; that's what I was there for. I noticed one beautiful red-head woman having a spirited conversation with someone. I tried to screw up courage to talk to her, and wait for a break in their conversation; say long enough to breathe. Then a beautiful blond lady approach me with a huge smile and her hand out for a handshake. My instinct is to respond to beautiful women the way Raj does on "The Big Bang Theory", but I screwed up the courage to not look away. She wanted to network as well. We talked about what we were trying to do with our respective businesses, and it sounded like cooperation was perfect. I glanced at the red-head, who glared at me with a huge pout. Apparently she noticed. Oh well, thinking I blew that one, I focused on the blond. I had a wonderful enthusiastic conversation with this beautiful woman. She said her company was named "Thoth", and asked if I knew what that was. I said it was the ancient Egyptian god of technology. Yes! She was impressed I knew that. Then noticed a group of guys had surrounded us. One asked me to ask her what her Ph.D. was in. I didn't know what that was about, so I just asked her. She looked defensive, and said ancient history. I tried to reassure her by saying I didn't even have a Ph.D. But as soon as I said that, all the guys turned their back and walked radially away. One guy stayed, with an incredible sad puppy dog face. I looked him, looked at her, then she said "Don't worry about him. He's just an employee." He dropped his head a skulked off. But I noticed she had a diamond ring on her left ring finger. Employee, eh? I didn't want to get in the middle of that. I wanted to keep it just business, but there never was any business.

I was afraid I had spoiled it with the red-head, but she and I did flirt the whole weekend. But I had to compete for her attention with another guy. Never did get anywhere with her.

A couple years later, at the 4th Canadian Space Exploration Workshop, I saw Caroline again. She noticed me sitting in the lecture hall. She took one step down the row of seats, looked at me, took another step, looked at me, etc. But the same guy she called an "employee" followed every step. As soon as they sat down, he got up and left the room. She got up and ran after him. Uh, huh. All very flattering for a nerd like me.

Today Caroline is named as the President and CEO of Thoth. That guy following her is Brendan, the Chief Technical Officer for Thoth. Good for them.

Ps. One project the Winnipeg chapter of the Mars Society looked at was building a dish array that could be used to receive telemetry from Mars probes past their normal mission life. For example, Mars Global Surveyor could have remained operating. We looked at getting a bunch of big satellite TV dishes that people threw away in favour of the small digital ones. Couldn't find enough to make it work. Then noticed an array of 3 metre dishes for radio astronomy was being decommissioned. Tried to get the Mars Society Canada involved to get our hands on that. But that array was taken by someone else. After trying for a couple years to get support for this project, Caroline and Brendan got a contract to operate the abandoned big dish in Algonquin park. It's a single steerable 46 metre dish. Out in the middle of a nowhere, in a large park that forms a radio quiet zone. And there's a small motel beside it. The Algonquin dish had sat abandoned for decades. Their first advertised application is telemetry, tracking & control services. Did my attempts inspire them? Good for them! They are accomplishing things much better than my failed attempts.

RobertDyck · 2015-08-12 20:42:48

Now to tear Brendan's idea apart.

A launch pad 20km in the air is very high in terms of structure, but not very high in terms of orbit. Communication satellites are in geosynchronous orbit, so they orbit once per day. That's 36,000km above Earth's surface. The advantage is low air pressure. Pressure at that altitude is 6 kPa, sea level is 101.325 kPa. That means rocket engine exhaust nozzles can be optimized for vacuum.

Stratolaunch is a giant aircraft designed to launch a rocket from high altitude. The aircraft doesn't provide significant speed or altitude, again the advantage is launch in near vacuum. Stratolaunch would launch the rocket from 30,000 feet (9.144 km). Air pressure is 32 kPa.

Could a tower stand that high? The patent talks about multiple segments with multiple cells each, using air pressure for structural support. The patent claims various gasses, so if anyone else builds this, they can claim royalties. The patent covers air, hydrogen, helium, and "not" which comes right after air so would imply "not air".
Patent: 9085897

Structural material is "cells consist of a material with high mass-to-tensile strength properties". Talk about vague. It then mentions a list: boron, and Kevlar polyethylene composite.

"stabilization devices further comprise gyroscopic wheels", and "stabilization devices further comprise gas compressor machinery".

Although the legalese at the beginning sounds like he hasn't worked out the math, the text does go into math. I would have check detail, but let's just say I'm skeptical a tower this tall would stand. Besides, would it be more economical than Stratolaunch?

SpaceNut · 2015-08-12 21:06:31

What is funny is that at the altitude we are supporting atoms for mass and yet by time we get to sea level its now 101.325 kPa or 14.7 PSI; so what would an airport weigh plus a plane or rocket to get the rest of the way.....once we magnify its mass different of atom to it....

Tom Kalbfus · 2015-08-13 01:13:07

The current air pressure us 10 tones per square meter, but what if we had a column of air that was 100 tons per meter at sea level? If it was 1000 tons per square meter, we could have a column of air that was 10 tons per square meter at 50 km, much as the atmosphere of Venus shows. A tower that high could support a 1 meter wide object that weighed 10 tons!

Spaniard · 2015-08-13 07:05:30

I don't know if balloons could ascend a "railgun" enough high to allow the "ship" to be launched to orbit speeds or enough speed to allow a SSTO.

Instead of a simple platform you could ascend a group of balloons to ascend a complete big magnetic rail launcher.
Bad system for manned because the high acceleration, but it could be ok for a lot of cargo.

Which speed could be reached at balloon altitude without too much friction?
Enough to allow a SSTO with a good fraction of rocket mass/cargo?

Tom Kalbfus · 2015-08-13 12:30:15

You don't need to launch it by railgun at orbital speed, just at a sufficient fraction of that speed to as to reduce the problem of the rockets in a single stage to orbit vehicle. Lets suppose we had a launch arch 20 km in radius. To reach 2 km per second, it would take 20 seconds to accelerate to the top of the arch, the horizontal acceleration over that 20 seconds would be 100 meters per second squared or a 10 g acceleration over 20 seconds, could a human survive that? After the space vehicle is released at the top of the arch, it would need to accelerate for 200 seconds at 3 g for three and a third minutes to reach an orbital velocity of 8 km/second.

SpaceNut · 2015-08-15 17:51:07

The walls of the tower will need to be as solid as steel/carbon nano tube to support compression of atmosphere in each sealed chamber as the rising structors mass will be carried by the section before it as it rises to the clouds.

Tom Kalbfus · 2015-08-15 19:44:13

SpaceNut wrote:

The walls of the tower will need to be as solid as steel/carbon nano tube to support compression of atmosphere in each sealed chamber as the rising structors mass will be carried by the section before it as it rises to the clouds.

The principle of gas compression is the same whether in inflatable bags or in metal cylinders, basically the idea is that the mass of the gas within is less than the mass of whatever solid you'd otherwise need to support the structure. For instance a column of air that is 100 km tall under Earth's gravity weighs 10 tons per square meter on the ground it sits on. Suppose we built walls around that column of atmosphere, and lets say we doubled the amount of air, you'd need walls that could hold in 10 tons per square meter on the sides near the bottom, the column of air within the column takes the place of steel girders. Now lets say we widened the tower to 10 meters by 10 meters, the top of the tower, all 100 square meters of it would experience an upward air pressure of 10 tons over 100 square meters, or 100 kg weights per square meter. You could place a 10 ton object on top of this tower and the air pressure underneath would support it and keep it at the 100 km altitude without it being in orbit or requiring the structure below to be lighter than air. (as it rests on the ground) A steel structure of similar height would be much more massive and would have to widen considerably towards the bottom to support its own weight, air tends to be less dense so the taper factor need not be as much as it would be for steel. There might be other uses for such things other than as launch platforms, for instance it could serve as a platform for a space telescope. A much more massive one than we could launch into orbit. Imagine the Keck telescope sitting on a tower 100 km above the surface, imagine what things it could see.

Tom Kalbfus · 2015-08-17 15:34:02

Altitude could be used to achieve orbital velocity if the tower was high enough. So how high would the tower have to be for a falling object to reach orbital velocity by the time it hit the atmosphere? Lets see, suppose you accelerated at 1 g lets call this 10 meters per second squared for ease of calculation, and lets say 8 km/sec is the orbital velocity, that is 8000 meters per second. Divide by 10 and you get 800 seconds. So how high above the atmosphere would you have to be in order to fall for 800 seconds?, average velocity is 4 km/second. 4km/sec times 800 seconds equals 3200 km, if we assume the atmosphere is 100 km high, we'd then have to build a tower that was 3300 km tall, drop something from the top of that tower and it will hit the atmosphere at 8 km/second, Maybe a small rocket can expend some propellant to make the falling object miss the Earth and go into an elliptical orbit.

tahanson43206 · 2022-11-07 16:30:10

The topic for this post was last updated in 2015...

Here is a link to a web site provided by a distributor of PVC pipe...

http://www.harrisonplastic.com/pvcsched … specs.html

I'm posting the link here because I have not given up on the development of one of Void's many ideas.

The web page at the link above shows a schedule of PVC pipe up to 24 inches OD.

The types of pipe are shown in two (I assume) grades: #40 and #80

It would appear (at first glance) that a mixture of the two types could be used to make a working model of an air-pneumatic lift.

This would be similar to the hydraulic pistons that are seen in service around the world, in construction and similar work.

(th)

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#1 2015-08-05 17:39:01

Inflatable space elevator gets a lift

#2 2015-08-06 09:22:21

Re: Inflatable space elevator gets a lift

#3 2015-08-11 17:24:28

Re: Inflatable space elevator gets a lift

#4 2015-08-11 19:29:18

Re: Inflatable space elevator gets a lift

#5 2015-08-12 18:28:25

Re: Inflatable space elevator gets a lift

#6 2015-08-12 19:49:37

Re: Inflatable space elevator gets a lift

#7 2015-08-12 20:42:48

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#8 2015-08-12 21:06:31

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#9 2015-08-13 01:13:07

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#10 2015-08-13 07:05:30

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#11 2015-08-13 12:30:15

Re: Inflatable space elevator gets a lift

#12 2015-08-15 17:51:07

Re: Inflatable space elevator gets a lift

#13 2015-08-15 19:44:13

Re: Inflatable space elevator gets a lift

#14 2015-08-17 15:34:02

Re: Inflatable space elevator gets a lift

#15 2022-11-07 16:30:10

Re: Inflatable space elevator gets a lift

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