Space Colony

[Moontanman]

Without water the whole topic is null and void. 

 

Very difficult to bring water.. Maybe there could be advancement in recycling urine and feces.

Sounds gross, but its the only realistic way at this point.

 

of course CraigD makes excellent statements regarding realities.

 

 

Space colonies will have to be made where the resources are, boosting them from earth is simply too expensive but other places are available and the Trojan points of Jupiter contain billions if not trillions of tons of consumables in orbit and there for the taking. Only the technology to use them needs to be developed.

 

In reference to materials to build these colonies carbon comes to mind, metals are too heavy and weak to be used as structural materials.  

Edited October 31, 2014 by Moontanman

[Eclogite]

In reference to materials to build these colonies carbon come to mind, metals are to heavy and weak to be used as structural materials.  

They are not especially heavy in space. :)

[Moontanman]

They are not especially heavy in space. 

 

 

They still have mass   :naughty:

[Moontanman]

As everyone here who knows me is I am sure aware of my liking for torus style colonies, like an endless suspension bridge. Metal is just to heavy to make really large structures but carbon nanotubes, sheets and fibers are stronger than steel and much lighter. Even Kevlar would be a much better construction material to make a torus that rotates to make artificial gravity on the inner surface.

 

Such structures made mostly of carbon could be made every place there is carbon containing ices or solids. The ort cloud, the Kuiper belt, such areas have everything needed to make colonies and the colony could ad water and other materials from nearby icy bodies when necessary.  In fact if we ever manage to control fusion in a way that produces energy instead of using it there would be no need to travel back into the suns gravity well and a colony could take up orbit around one of these icy bodies and have raw materials to last millenia.

 

Just my two cents...  

[Moontanman]

I wonder if there is a computer program that would allow me to design things, mechanical drawing type stuff, any one know? 

[Buffy]

I wonder if there is a computer program that would allow me to design things, mechanical drawing type stuff, any one know? 

 

You might want to take a look at this list of free CAD programs. There are lots of others too, but I don't really play with them.

 

 

Design is a funny word. Some people think design means how it looks. But of course, if you dig deeper, it's really how it works, :phones:

Buffy

[CraigD]

As everyone here who knows me is I am sure aware of my liking for torus style colonies, like an endless suspension bridge. Metal is just to heavy to make really large structures but carbon nanotubes, sheets and fibers are stronger than steel and much lighter.

Though I’ve not (and, having only a amateur grasp of engineering, likely couldn’t well) validate it in detail, the 1975 Stanford University/Ames Research Center study from which the Stanford Torus takes its name had a lot of engineers in it, and concluded that an 830 m radius torus capable of providing 0.9 g of centrifugal pseudogravity to 10,000 people could be made from conventionally refined and fabricated aluminum. Their plan called for it to be mined on the moon and thrown to the construction site, in loads of a few tens of kgs, by a big superconducting electromagnetic accelerator. See (and be prepared to wade through material before the age of widespread hyperlinks) NASA’s “Space Settlement: A Design Study”

 

Because of the much higher strength and lower mass of present-day carbon fiber material – technology in its infancy in 1975 - I’m pretty sure a better Stanford Torus could be made using them. However, even now, strong carbon fiber material is expensive, difficult to manufacture in the quantities needed for a 10,000 person spacecraft, and more difficult to handle (ie: it can’t simply be melt-welded or bolted together) than metal. The Lunar surface is 15-25% Aluminum oxide, but carbon is rare.

 

Given this, I’m far from sure that a modern revisiting the of design study that gave us the Stanford Torus would chose carbon fiber or more exotic non-metals (eg: diamond) over Aluminum.

[Moontanman]

Though I’ve not (and, having only a amateur grasp of engineering, likely couldn’t well) validate it in detail, the 1975 Stanford University/Ames Research Center study from which the Stanford Torus takes its name had a lot of engineers in it, and concluded that an 830 m radius torus capable of providing 0.9 g of centrifugal pseudogravity to 10,000 people could be made from conventionally refined and fabricated aluminum. Their plan called for it to be mined on the moon and thrown to the construction site, in loads of a few tens of kgs, by a big superconducting electromagnetic accelerator. See (and be prepared to wade through material before the age of widespread hyperlinks) NASA’s “Space Settlement: A Design Study”

 

Because of the much higher strength and lower mass of present-day carbon fiber material – technology in its infancy in 1975 - I’m pretty sure a better Stanford Torus could be made using them. However, even now, strong carbon fiber material is expensive, difficult to manufacture in the quantities needed for a 10,000 person spacecraft, and more difficult to handle (ie: it can’t simply be melt-welded or bolted together) than metal. The Lunar surface is 15-25% Aluminum oxide, but carbon is rare.

 

Given this, I’m far from sure that a modern revisiting the of design study that gave us the Stanford Torus would chose carbon fiber or more exotic non-metals (eg: diamond) over Aluminum.

 

 

So you assume that this difficulty will always be true? We make kevlar fibers rather easily, kevlar is much stronger than aluminum.  

[Moontanman]

I was thinking more along the lines of weaving the fibers together, I have an image in my mind but I can't make an image of it. The torus would be three miles across and one mile thick, carbon nano tubes would be woven much like a Spirograph drawing appears to be. The fibers would anchor in the middle by weaving around each other. 

[Moontanman]

I would spin it for 1/4 earth normal gravity.

[Moontanman]

It's also interesting that kevlar is strong enough to use to build a space elevator on Mars... 

[CraigD]

… Given this, I’m far from sure that a modern revisiting the of design study that gave us the Stanford Torus would chose carbon fiber or more exotic non-metals (eg: diamond) over Aluminum.

So you assume that this difficulty will always be true?

Not at all. I’m considering what could be done right now, present day, to build a space habitat.

 

Assuming that a Stanford Torus or other kind of space habitat can’t be built using present day technology promotes, I think, an attitude of inaction and waiting for new technology that may or may not be soon available. Building a space habitat soon – say in the next 10 years – largely using technology that’s existed for 50+ years doesn’t prevent better technology from being developed. Rather, I think, it encourages it.

 

We make kevlar fibers rather easily, kevlar is much stronger than aluminum.

Kevlar fiber has a very high tensile (pulling) strength, making it an excellent for rope cores. It’s nearly standard for rigging and railings on high-end sailboats these days, and has been used for suspension cables in this 22000 kg, 114 m long foot bridge.

 

I can see 2 killer drawbacks to replacing the aluminum in a Stanford Torus with materials like Kevlar, though:

• First, the same property that makes it ideal for fabric and rope – flexibility – means that Kevlar and other fibers have practically no compressive strength. So while they’re excellent for parts of structures like a suspension bridge or space habitats, other materials are needed for most of the structure’s material.
• Second, aramid fibers like Kevlar are hydrocarbons, synthesized from hydrocarbons. Because of biology, Earth is rich with petroleum, from which the benzene and hydrogen precursors manufacturing Kevlar can be extracted. But hydrocarbon sources are rare in space, including the surface of the Moon. So you’d have to lift the Kevlar used in a space habitat from Earth, which is much more energy and money costly than the Stanford scheme of launching aluminum ore from the Moon.

The best reference I’ve found on Kevlar is this Dupont technical guide.

[Moontanman]

Not at all. I’m considering what could be done right now, present day, to build a space habitat.

 

Assuming that a Stanford Torus or other kind of space habitat can’t be built using present day technology promotes, I think, an attitude of inaction and waiting for new technology that may or may not be soon available. Building a space habitat soon – say in the next 10 years – largely using technology that’s existed for 50+ years doesn’t prevent better technology from being developed. Rather, I think, it encourages it.

 

Kevlar fiber has a very high tensile (pulling) strength, making it an excellent for rope cores. It’s nearly standard for rigging and railings on high-end sailboats these days, and has been used for suspension cables in this 22000 kg, 114 m long foot bridge.

 

I can see 2 killer drawbacks to replacing the aluminum in a Stanford Torus with materials like Kevlar, though:

• First, the same property that makes it ideal for fabric and rope – flexibility – means that Kevlar and other fibers have practically no compressive strength. So while they’re excellent for parts of structures like a suspension bridge or space habitats, other materials are needed for most of the structure’s material.
• Second, aramid fibers like Kevlar are hydrocarbons, synthesized from hydrocarbons. Because of biology, Earth is rich with petroleum, from which the benzene and hydrogen precursors manufacturing Kevlar can be extracted. But hydrocarbon sources are rare in space, including the surface of the Moon. So you’d have to lift the Kevlar used in a space habitat from Earth, which is much more energy and money costly than the Stanford scheme of launching aluminum ore from the Moon.

The best reference I’ve found on Kevlar is this Dupont technical guide.

 

 

 

Hydrocarbons are rare in space? Hydrocarbons are everywhere, comets to asteroids are lousy with carbon and hydrocarbons. 

 

If such a body was rotating, air tight, and pressurized I can see no reason why it wouldn't be strong, remember the idea is a stressed structure like a suspension bridge. The fibers would comprise the outside coil around the tube and the rotation would keep it's shape. I wish I could draw what i am thinking of, I've been trying to figure out why my new cell phones has started sending all my video as mp4 files which my computer will not read, it didn't do that the first few times, I haven't had the chance to check out the drawing sites Buffy recommended.. 

[Moontanman]

I used to work for DuPont, the fibers division, I've watched kevlar being made and helped train people to make it. 

[CraigD]

I used to work for DuPont, the fibers division, I've watched kevlar being made and helped train people to make it

With which stages of making Kevlar are you familiar, Moontanman?

 

I’m not a chemist (have had the 8 lab/lecture hours usual for a science undergrad), and would love to see someone with more skill at it lay out the details of making hydrocarbon polymers and polyamides from ET resources.

 

As with most synthetic fibers, there are a lot of them: getting raw precursor stuff (on Earth, drilling or shale-mining oil, and any of many ways of getting ammonia), then several chemistry steps to get the precursors for the last step mentioned in its Wikipedia,

C₆H₈N₂ + C₈H₄Cl₂O₂ -> 2HCl + C₁₄H₁₀O₂N₂ (=Kevlar!)

, then physically cold-extruding/spinning and gathering the fibers (unlike fibers like Nylon Kevlar isn’t extruded as a melted liquid).

 

Hydrocarbons are rare in space? Hydrocarbons are everywhere, comets to asteroids are lousy with carbon and hydrocarbons.

I’m neither a chemist nor a planetary astronomer (Though I did intern for a few months as one :)) but I think I have a reasonable idea of the problems of making hydrocarbon polymers and polyamides in space with technology likely to exist in the next few decades. Breaking down my “hydrocarbons are rare in space” point:

 

By usual manufacturing standards, everything is rare in space, the space where we’d be building a large (10000 people) space habitat. Space is nearly a perfect vacuum, with a faint flux of hydrogen gas and plasma, and barely detectable traces of larger atoms, molecules and particles.

 

To get practical amounts of any material, you’ve got to go to a body – Earth, the Moon, an asteroid, comet, or ET planet or moon. With present technology, sizable quantities of stuff can be gotten from Earth, the Moon, perhaps Mars and Venus, and a few favorably orbiting asteroids and comets.

Of these, big bodies like Earth, though rich in the stuff you need, take a lot of energy and machinery to throw it out of their deep gravity wells to your space construction site. Small bodies like comet and asteroids have practically no gravity well, but take a lot of energy and machinery to reach and return stuff from, or capture and deliver whole. ET moons have moderate gravity wells, but also take a lot of energy to reach and return stuff from.

 

This leave us at the same conclusion the Stanford team reached in 1975: the Moon as the most practical source of materials for a space habitat.

 

The Moon is believed to vents traces of CH₄ (methane) from its surface, and may have some from comet collisions in cold traps (frozen shadows). I think it’s very unlikely sufficient quantities for manufacturing even small quantities of hydrocarbon polymers and polyamides like Kevlar could be gotten on the Moon with any technology likely in the next century.

 

There are big deposits of CH₄ on many ET bodies. Comets are thought to have frozen deposits of them – though how much, and how they could be mined is uncertain, and the energy and hardware cost of comet intercept and return or capture missions is high, perhaps making them less economical than launching finished materials from Earth.

 

The atmospheres of Mars and many or all of the gas giant planets and some of their biggest moons have small fractions of methane. Collecting enough of it to build hydrocarbon-derived materials for a space habitat would, I think, take machines massing more than the space habitat.

 

The surface of Saturn’s moon Titan appears to have cryogenic pools of liquid methane and C₂H₆ (ethane) on its surface, and a thick (about 1.2 times denser than Earth’s) atmosphere with lots (about 1.6%) methane. It might even sands containing hydrocarbons like C₂H₆ (benzene), caused by sunlight reacting with its atmospheric methane. It likely has frozen surface NH₃ (ammonia) and H₂O (water), and a vast subsurface amonia-water ocean perhaps 10 times larger than Earth’s surface oceans. (Source Aricibo’s PHL’s “Liquid Water in the Solar System”) Except that it likely very metal-poor, with a hydrous silicate core, rather than the iron core, it’s likely an energy and chemical manufacturing dream world.

 

Getting stuff off of Titan would be an unusual spaceflight challenge. It has about 1.8 times the Moon’s mass, though only about 0.85 times its surface gravity, but the above mentioned thicker-than-Earth’s atmosphere.

 

Titan would be a wonderful moon to have near a planned space habitat.

 

The killer problem with Titan as a space habitat supply house is that it’s further (around 20 time further than Mars) than I can conceive of many humans, or substantial Earth-made hardware, traveling to.

 

If the challenge of human spaceflight of such distance could be solved, it would likely be more attractive for them to live on titan than in space near it.

 

Though a speculative stretch so far attempted only in SF (most notably in my reading, in Michael McCollumn’s 1991 hard-SF space adventure novel The Clouds of Saturn), it’s not beyond reason that the atmosphere of Saturn itself could be suitable for human colonization.

[Moontanman]

With which stages of making Kevlar are you familiar, Moontanman?

 

I’m not a chemist (have had the 8 lab/lecture hours usual for a science undergrad), and would love to see someone with more skill at it lay out the details of making hydrocarbon polymers and polyamides from ET resources.

 

As with most synthetic fibers, there are a lot of them: getting raw precursor stuff (on Earth, drilling or shale-mining oil, and any of many ways of getting ammonia), then several chemistry steps to get the precursors for the last step mentioned in its Wikipedia,

C₆H₈N₂ + C₈H₄Cl₂O₂ -> 2HCl + C₁₄H₁₀O₂N₂ (=Kevlar!)

, then physically cold-extruding/spinning and gathering the fibers (unlike fibers like Nylon Kevlar isn’t extruded as a melted liquid).

 

I’m neither a chemist nor a planetary astronomer (Though I did intern for a few months as one :)) but I think I have a reasonable idea of the problems of making hydrocarbon polymers and polyamides in space with technology likely to exist in the next few decades. Breaking down my “hydrocarbons are rare in space” point:

 

By usual manufacturing standards, everything is rare in space, the space where we’d be building a large (10000 people) space habitat. Space is nearly a perfect vacuum, with a faint flux of hydrogen gas and plasma, and barely detectable traces of larger atoms, molecules and particles.

 

To get practical amounts of any material, you’ve got to go to a body – Earth, the Moon, an asteroid, comet, or ET planet or moon. With present technology, sizable quantities of stuff can be gotten from Earth, the Moon, perhaps Mars and Venus, and a few favorably orbiting asteroids and comets.

Of these, big bodies like Earth, though rich in the stuff you need, take a lot of energy and machinery to throw it out of their deep gravity wells to your space construction site. Small bodies like comet and asteroids have practically no gravity well, but take a lot of energy and machinery to reach and return stuff from, or capture and deliver whole. ET moons have moderate gravity wells, but also take a lot of energy to reach and return stuff from.

 

This leave us at the same conclusion the Stanford team reached in 1975: the Moon as the most practical source of materials for a space habitat.

 

The Moon is believed to vents traces of CH₄ (methane) from its surface, and may have some from comet collisions in cold traps (frozen shadows). I think it’s very unlikely sufficient quantities for manufacturing even small quantities of hydrocarbon polymers and polyamides like Kevlar could be gotten on the Moon with any technology likely in the next century.

 

There are big deposits of CH₄ on many ET bodies. Comets are thought to have frozen deposits of them – though how much, and how they could be mined is uncertain, and the energy and hardware cost of comet intercept and return or capture missions is high, perhaps making them less economical than launching finished materials from Earth.

 

The atmospheres of Mars and many or all of the gas giant planets and some of their biggest moons have small fractions of methane. Collecting enough of it to build hydrocarbon-derived materials for a space habitat would, I think, take machines massing more than the space habitat.

 

The surface of Saturn’s moon Titan appears to have cryogenic pools of liquid methane and C₂H₆ (ethane) on its surface, and a thick (about 1.2 times denser than Earth’s) atmosphere with lots (about 1.6%) methane. It might even sands containing hydrocarbons like C₂H₆ (benzene), caused by sunlight reacting with its atmospheric methane. It likely has frozen surface NH₃ (ammonia) and H₂O (water), and a vast subsurface amonia-water ocean perhaps 10 times larger than Earth’s surface oceans. (Source Aricibo’s PHL’s “Liquid Water in the Solar System”) Except that it likely very metal-poor, with a hydrous silicate core, rather than the iron core, it’s likely an energy and chemical manufacturing dream world.

 

Getting stuff off of Titan would be an unusual spaceflight challenge. It has about 1.8 times the Moon’s mass, though only about 0.85 times its surface gravity, but the above mentioned thicker-than-Earth’s atmosphere.

 

Titan would be a wonderful moon to have near a planned space habitat.

 

The killer problem with Titan as a space habitat supply house is that it’s further (around 20 time further than Mars) than I can conceive of many humans, or substantial Earth-made hardware, traveling to.

 

If the challenge of human spaceflight of such distance could be solved, it would likely be more attractive for them to live on titan than in space near it.

 

Though a speculative stretch so far attempted only in SF (most notably in my reading, in Michael McCollumn’s 1991 hard-SF space adventure novel The Clouds of Saturn), it’s not beyond reason that the atmosphere of Saturn itself could be suitable for human colonization.

 

 

I worked in the textile fibers division of the DuPont company, mostly on the lower end and not the upper. Our Plant made dacron out of liquid monomers but kevlar had some things in common with dacron, how it is spooled in continuous filaments being the most basic. 

 

I'm not sure what you want to know, oil was our main feedstock but complex hydrocarbons can be made from methane and quite literally kevlar is strong enough to use as hoses to pump methane up from the surface of titan, probably not practical but methane ice is quite common on small bodies like comets and small moons and hydrocarbons are in asteroids as carbonaceous chondrites.

 

I honestly think that the age of making stuff out of metal will end in favor of making things out of fiber reinforced plastics.

 

Methane should be quite common out as far as Jupiter as clathrates , they certainly exist on the earth in huge quantities.

 

the Trojans of Jupiter should be much easier to extract minerals from to build space objects than the moon and once you get into earth orbit those trojans are not any or at least not much harder to reach than the moon and much easier to remove since gravity is not a big factor.  

[Racoon]

Does anyone realize how weak the Astronauts will be after 7 monhs in Zero-Gravity??

 

They wouldn't have the strength to push a pencil...