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I think he's referring to atmospheric turbulence that could cause catastrophic levels of mechanical stress on large rigid structures.
The question remains, what is it about the Venusian atmosphere that makes it an attractive residential target for colonization?
Combination of air pressure, temperature and normal gravity. On Venus, these are right conditions for humans in the upper atmosphere.
Also, the abundance of Solar energy gives it an advantage compared to Earth and Mars. There are a few useful chemicals in abundance in its atmosphere like sulphuric acid, nitrogen (useful for making Earth like breathable air).
The thickness of the atmosphere will also give limited protection against solar radiation and meteorites.
Admittedly, you have to import a lot materials to live here but once they're there put in the right location - it can become a very good place to live. Asteroids and various moons have a lot of the right materials, but they lack the gravity, atmosphere and closeness to the sun to be useful places for supporting human life.
Eventually, The materials on the surface of the planet will become exploitable but we don't have to live on the surface to do that.
Terraformer -
All fluids can have vortices can they not? And all "light fluids" like air can experience sudden pressure drops where aircraft can fall tens of thousands of feet in a few seconds. I doubt we know enough about the Venusian atmosphere to say how difficult it would be to live in.
Aircraft don't fall tens of thousands of feet in seconds during turbulence. Its a small small fraction of that. The air doesn't experience a sudden pressure drop, the aircraft flies in to an area of lower pressure.
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Gregori -
There are catastrophic drops in pressure where aircraft do fall out of the sky, literally. I'm not talking about normal turbulence.
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Oh, that's what you mean. But seriously: How often do planes fall out the sky? People still fly on Planes.
Use what is abundant and build to last
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Oh, that's what you mean. But seriously: How often do planes fall out the sky? People still fly on Planes.
not very.
Mars has equally bad problem for those proposing a 'dome'. Its thin atmosphere will be crap at screening even small meteors. A meteor could quickly depressurize a settlement and kill everybody in it. Even regular a mechanical failure could destroy a settlement. The temperature fluxes very quickly between extremes on Mars so mechanical failure will happen more often.
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Terraformer: More often than you'd think.
Gregori: Obviously small meteorites are not a problem for entrenched inflatables covered by regolith.
However, I agree the issue is more complex with domes and will need to be looked at.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Ok, what do we do about the acid?
Presumably your going to want to use as much carbon in your structures as possible, how does it react with acid, and what can we use to protect it and other materials?
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Ok, what do we do about the acid?
Presumably your going to want to use as much carbon in your structures as possible, how does it react with acid, and what can we use to protect it and other materials?
That was discussed a little bit here ...
Floating Venusian cities or Venus vs Mars vs Titan revisited
http://www.newmars.com/forums/viewtopic.php?t=5322
... you can use a diamond coating ( e.g., see http://www.sandia.gov/media/diamond.htm ). Also, the sulphuric acid is very concentrated and actually isn't as reactive as the more dilute kinds (i.e., diluted with water). It would be a problem analogous with rust rather than with clouds of lava that dissolve your floating city.
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Ok, what do we do about the acid?
Presumably your going to want to use as much carbon in your structures as possible, how does it react with acid, and what can we use to protect it and other materials?
Bottle it and use it!
Apart from that, there will be some material that can resist sulphuric acid. Use that as the outer coating on the installation. It doesn't have to be a carbon outer layer. A useful material for the protective coating could come from elsewhere in the solar system.
Living on Venus doesn't mean that all the necessary materials need to come from Venus. Asteroids, The Moon, Mars could provide useful minerals
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The material you are looking for that doesn't react with Sulpheric Acid is called... Sulpher. All that is needed is a Sulpher coating; the Sulpher will be a Byproduct of extracting Water and Oxygen from the Sulpheric Acid.
Check out these two Wikipedia articles. They're partly what convinced me Venus is a better target.
http://en.wikipedia.org/wiki/Colonization_of_Mars
http://en.wikipedia.org/wiki/Colonization_of_Venus
It's interesting the surface of Mars is the third most hospitible place in the Solar System, Venus's cloudtops being the second.
Mars is kind of a non-issue, as we can't actually land. We can crash though, if that's how you intend to get someone there.
Use what is abundant and build to last
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Terraforming is a slow process in better case.
If we talk about colonization, i think that any subterranean colony is easy to construct that a floating like the propositions for Venus
A subterranean site and enough deep is protected from ratiation and could be sustained artifially. Light, air, even gravity using artificial pseudogravity with rotation in a cone rotating building (like space torus, but with partial gravity, the geometric form was a cone).
I think the best place for a colony is the moon, because colonization will be maked using controled remote robots and we are at Earth enough near to control robots very similar to real time.
The experience in total autonomous closed colonies could be easily exported to Mars.
But I see Mars the most attractive place to live (with exception of Earth, of course) in medium times, because is the better place to build outer domes colonies where living could be enough comfortable.
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I think people are vastly overestimating the difficulty of constructing a floating city in Venus's atmosphere.
Use what is abundant and build to last
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I think people are vastly overestimating the difficulty of constructing a floating city in Venus's atmosphere.
Ohhh It will be very very difficult! It will take some amazing engineering and trillions of dollars to make it work. But living on Mars will also be very difficult. We probably won't see a viable colony on Mars for 50-100 years time
The important point is that its not impossible.
When we do settle outer space, I don't think we should put all our eggs in one basket. Settling in several locations and trading useful good between them would be a much better idea.
An infrastructure should be built up to facilitate this.
I think the first step is designing a machine to extract useful amounts of oxygen from the Lunar Regolith for refueling spacecraft and providing breathable air.
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Gregori -
"But living on Mars will also be very difficult."
Let's assume we can get to Mars. What then is the great difficulty in living on Mars? I don't really see it myself. Is it in principle so very different from living in Antarctica over winter given there is also no soil, no natural vegetation, no running water, and extreme cold? An Antarctic winter has the added disadvantage of no natural light of course.
And yet, crops are now being grown at Antarctic bases. I haven't actually heard of any base workers actually dying because of the extreme conditions.
We have lived on the Moon for several days. People have lived in the ISS for a year or more. People have survived in Antarctica.
What is it about Mars that makes it impossible to set up a colony in the next say 10 years (leaving aside the difficulties of getting there, which I accept are a challenge).
When you say "colony" are you thinking of some grand metropolis? I can understand why that will not be viable for some time. But a modest colony focussed on research is well within our grasp I would say. Essentially that is because we now have an energy solution (solar), a food solution (hydroponic farming), and a habitat solution (entrenched inflatables with aerogel insulation). Added to that we have the ability to import industrial capability in the shape of a range of small scale machines: oxygen and other gas extractors, smelters, automated glass blowing, computer controlled lathes etc etc which will give us the products of an industrial society from a tiny, tiny mass.
I think we can go rapidly from the landing to a colony of 20 people - maybe within 10 years. In the ten years after that I think we could go to 100. Once we are able to construct domes using ISRU, we can think in terms of 1000s of colony residents.
What is stopping us?
I think the only serious brake on colony development will be the cost of interplanetary travel. That is still a big unknown. But development of a lunar base does hold out the promise of reducing space travel costs through LEO refuelling.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Gregori -
"But living on Mars will also be very difficult."
Let's assume we can get to Mars. What then is the great difficulty in living on Mars? I don't really see it myself. Is it in principle so very different from living in Antarctica over winter given there is also no soil, no natural vegetation, no running water, and extreme cold? An Antarctic winter has the added disadvantage of no natural light of course.
And yet, crops are now being grown at Antarctic bases. I haven't actually heard of any base workers actually dying because of the extreme conditions.
We have lived on the Moon for several days. People have lived in the ISS for a year or more. People have survived in Antarctica.
What is it about Mars that makes it impossible to set up a colony in the next say 10 years (leaving aside the difficulties of getting there, which I accept are a challenge).
When you say "colony" are you thinking of some grand metropolis? I can understand why that will not be viable for some time. But a modest colony focussed on research is well within our grasp I would say. Essentially that is because we now have an energy solution (solar), a food solution (hydroponic farming), and a habitat solution (entrenched inflatables with aerogel insulation). Added to that we have the ability to import industrial capability in the shape of a range of small scale machines: oxygen and other gas extractors, smelters, automated glass blowing, computer controlled lathes etc etc which will give us the products of an industrial society from a tiny, tiny mass.
I think we can go rapidly from the landing to a colony of 20 people - maybe within 10 years. In the ten years after that I think we could go to 100. Once we are able to construct domes using ISRU, we can think in terms of 1000s of colony residents.
What is stopping us?
I think the only serious brake on colony development will be the cost of interplanetary travel. That is still a big unknown. But development of a lunar base does hold out the promise of reducing space travel costs through LEO refuelling.
its looks easy on paper, when you don't consider the practicalities.
We could do a research station on Mars. It's difficult but feasible. A self sustaining colony is a different matter altogether. Antartica bases aren't built from insitu resources, its' all shipped to Antartica. Most of its residents are not permanent. The Same will be true of Mars for a long long time. It will be a research base that mainly subsists from Earth supplies.
If it where easy, it would have been done by now. However its hasn't. We aren't even sure of all the difficulties that will face us as research on this planet is still a young field.
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How can you liken living on Mars to living in Antartica? In Antartica you still have a 1 bar atmosphere with Oxygen. Mars is a 1 millibar CO2 atmosphere.
You don't seem to be grasping quite how much lift Hydrogen would give on Venus. In a 1 bar nearly all CO2 atmosphere, quite a lot. A colony would have a central stalk hanging below and a landing strip for craft on the top.
Use what is abundant and build to last
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I have been reading the post about going to Venus. My question is Why? If I understand it right the sun is only going to get hotter and hotter. I thing we should be heading out.
Vincent
Argument expected.
I don't require agreement when presenting new ideas.
-Dana Johnson
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It's true that most consumables in Antarctic research stations are not produced from ISRU (although I believe they do use solar and wind power).
However, the only reason is that the earth based cost of flying in or shipping consumables to the Antarctic is far cheaper than would be using ISRU.
But these expenses would need to be seen, in relation to Mars, in the context of perhaps a $40billion project over ten years. It would NOT cost a billion dollars to to provide the ISRU structure for a small colony of up to 20 people. It wouldn't cost even 100 million dollars I think. Probably somewhere between 10 and 100 million dollars. Essentially all the machines are in existence. They just need to be adapted to Mars conditions and made as light as possible to reduce the mass we are carrying to Mars. Particular attention will need to be paid to those machines that will be operating in the outside environment e.g. the digger. However, we know from the Mars Rovers that such machines can be produced. Remember also that with humans around these machines can be made a lot less sophisticated.
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I have been reading the post about going to Venus. My question is Why? If I understand it right the sun is only going to get hotter and hotter. I thing we should be heading out.
Vincent
Yeah, but what happens in a Billion years is hardly relevant to a colony now.
Venus has a shitload of useful energy and a habitable zone now.
It's true that most consumables in Antarctic research stations are not produced from ISRU (although I believe they do use solar and wind power).
However, the only reason is that the earth based cost of flying in or shipping consumables to the Antarctic is far cheaper than would be using ISRU.
But these expenses would need to be seen, in relation to Mars, in the context of perhaps a $40billion project over ten years. It would NOT cost a billion dollars to to provide the ISRU structure for a small colony of up to 20 people. It wouldn't cost even 100 million dollars I think. Probably somewhere between 10 and 100 million dollars. Essentially all the machines are in existence. They just need to be adapted to Mars conditions and made as light as possible to reduce the mass we are carrying to Mars. Particular attention will need to be paid to those machines that will be operating in the outside environment e.g. the digger. However, we know from the Mars Rovers that such machines can be produced. Remember also that with humans around these machines can be made a lot less sophisticated.
It WILL cause Billions, make no mistake about that. Just look at the history of space exploration. The Apollo program didn't use any very advanced robotics but it cost bllions.
It requires lifting loads of very heavy machines all the way to Mars and landing them without damaging them.
That doesn't mean it can't be done but don't underestimate the task at hand. It can't be done on the cheap. If we want a good ISRU infrastructure it will cost us.
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Why? A few on this thread keep arguing for floating cities on Venus, but why? What's the point?
Mining asteroids can provide gold, silver, and the complete platinum group of metals: platinum, palladium, iridium, rhodium, ruthenium, and osmium. That's all 8 precious metals. The metal asteroids are rich in them. I have already made a presentation at a Mars Society conference how we can harvest them and bring them back to Earth economically. It would be automated, astronauts only going out to fix equipment and hopefully not even that.
On Mars we can transport setters from Earth. They can build homesteads using local materials, mined from the ground. A habitat the size of a farm house, with either sand bags filled with Mars regolith or dirt from a hillside pulled down on their roof for radiation protection. As long as the homestead is built below the datum, that's all you need. A greenhouse using ambient light, with fluorescent lights or white LEDs as backup. An aluminized mylar curtain that is strung horizontally across the ceiling of the greenhouse, as well as inside the walls; closed at night and open during the day to contain heat. During a sandstorm that can also reflect light from the light fixtures, keeping all the light inside. Use PCTFE film for an inflated greenhouse on a science mission, but glass for a permanent base built of in-situ materials.
I could go on and on, but the economics of Mars are different than many people expect. Settlers will sell their house and liquidate all their assets for a ticket to Mars. They'll arrive with only a few suitcases. That ticket will be paid in Earth dollars. However, the economy of Mars can maintain and operate the interplanetary spacecraft. Fuel for the return to Earth will come from either Mars or one of its moons. Fuel for the trip from Earth orbit will come from a near Earth asteroid, a C-type carbonaceous chondrite asteroid with ice crystals. With tickets paid in Earth dollars, but expenses paid by the Martian economy, revenue will come from settlers themselves. The company that owns the settler transport ship will also own Mars fuel facility, NEO asteroid fuel mine, and a city on Mars that receives new settlers. With all new arrivals coming there, expect it to grow as much as New York did; a new Ellise Island. That city will produce equipment, food, and other supplies to operate the interplanetary ship. The company will also hire new immigrants, who will have to work to earn a grub steak for equipment to build a homestead. It will also produce goods to supply those homesteaders.
A whole colonist economy. No physical thing has to come back from Mars to pay the Earth investors, return on investment will be in Earth dollars to pay for tickets. You do need to ensure settlers can build their homestead, and can live independent in a frontier environment free of overbearing regulation. It must be very libertarian, otherwise why would any citizen of Earth spend his/her entire life savings for a ticket? There must be great effort to ensure homesteaders live a successful life to sustain the dream that will draw new settlers. After all, new immigrants from Earth are the source of Return-On-Investment to be paid to Earth share holders.
So asteroids and Mars work. This comes back to Venus. Once Venus is terraformed it will have a full atmosphere, 90.695% gravity, 90.03% as much surface area as Earth, and plenty of sunlight. But how does a floating cloud city make money? I don't see private, single-family homesteads working in the clouds. You need a large industrial operation to extract enough hydrogen for lift gas, extract gasses to produce plastics for manufacture, or maintain aircraft that can descend into the intense pressure, heat, and corrosive of the lower atmosphere today to mine metals. If supporting private homesteaders is not the basis of the economy, and asteroids can produce precious metals for Earth much more cheaply, what would be the economic benefit?
To sumarize a long winded argument: where's the money?
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So what would these settlers be doing other than working in factories or farms, which they'd be doing on Venus? Mining?
I admit; Venus isn't the best off world place to Colonize. But that doesn't make Mars the best.
If you want somewhere near Mars to colonize, colonize the Moons. A hab on Mars has to have the same equipment and structure, so why not remain in Orbit? Remaining in space near either Phopos or Deimos offers numerous advantages. These Moons are volatile rich, unlike Mars. Colonies can be spun to create Eratz gravity. You remove the Gravity well. Those are a few I could come up with off the top of my head. The moons could be eventually transformed into large colonies.
The overriding aim, and generally only use, for Mars and Venus is Terraformation. They don't really have any other use. Venus has the advantage of greater gravity and the fact that it's closer with more launch windows. The're equally difficult to colonize, Venus maybe less, so Venus is the obvious choice if you're so intent on colonizing a planet.
Comets and Asteroids are really the best places to colonize. They have materials for radiation protection without a big gravity well to get out of.
Use what is abundant and build to last
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Protection against heavy ion cosmic radiation, and I mean about the size of iron nuclei, are extremely difficult to shield against. Lead or anything heavy will break up from high speed heavy ions, or the ions will break, or both. The result is lower speed particles, but more radiation particles. The number of cell hits determines damage to the human body, not the energy of the particles, so mild shielding can actually make heavy ion radiation worse. That's why some engineers are looking a liquid hydrogen as shielding, hydrogen has a single proton in the nucleus so can't split, and it's so light that each hit will gently reduce the speed of heavy ions rather than split them. Well, it turns out the atmosphere of Mars is ideal shielding for heavy ion radiation. Roughly 99% of heavy ion radiation will not make it to the surface; the catch is to pick a base location below the datum. You need a low location so you have a lot of atmosphere over your head for shielding.
Other forms of radiation are easier to block. Alpha radiation can be blocked by a single sheet of aluminum foil. Beta radiation is even weaker, it can be blocked by a single sheet of paper, film of plastic, or even human skin. NASA already developed a spectrally selective coating for spacecraft windows that lets visible light through but blocks 99.9% of UV. Since it's metal it also blocks most of X-rays. That leaves gamma rays, proton radiation, and light ion radiation. Those are easily blocked by sandbags.
As I've said on other threads, a calculation shows that if a Mars base or settlement is built below the datum, and has sandbags or a hillside piled on the roof, then radiation exposure can be kept within the current US regulator limits for a nuclear reactor worker simply by restricting astronauts to no more than 40 hours per week outside on the surface. That's 40 hours per week in a spacesuit. The airlock will have sandbags on the roof as well, so time in the airlock doesn't count. An ambient light greenhouse will not have sandbags, so even though it will be a shirt-sleeve environment, time in the greenhouse does count. But 40 hours per week is a work week; I don't think anyone would object.
The moon is quite different; no atmosphere. That means a lot of radiation. Asteroids or the moons of Mars, which are basically captured asteroids, have the radiation problem but they also have practically no gravity. The 1/6 gravity of Luna (Earth's moon) many be a problem for long-term exposure, we just don't know, but I suspect the 38% gravity on Mars is enough. Then there's micrometeoroids; they can't get through the atmosphere of Mars, so you only have to worry about sand storms and rubbing against rocks. Luna or asteroids do have micrometeoroids.
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Very interesting comments Robert.
I'm pleased to see you feel 38% gravity will be enough to protect human physiology from harm .That's my hunch as well.
I agree we'll have to restrict outside working but 40 hours sounds more than enough. I think actually that there may not be much need for outside working once the habitat has been constructed, although I think regular outside sorties will be important psychologically. Solar panels will probably need cleaning with blowers on a fairly regular basis (once every two days would be my guess).
One thing that occurs to me. If we do have covered habitats, it would be good to have lightweight screens that could reproduce the outdoor scene (recorded by wifi connected cameras). That way the colonists will feel connected to the outside world and the day/night cycle. I think work has been done on electronic paper and so a lightweight display might be a possibility in a few years' time.
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The overriding aim, and generally only use, for Mars and Venus is Terraformation. They don't really have any other use. Venus has the advantage of greater gravity and the fact that it's closer with more launch windows. The're equally difficult to colonize, Venus maybe less, so Venus is the obvious choice if you're so intent on colonizing a planet.
Why? Terraforming would be an enormous waste of energy and time with little return.
Adapting technology so that its possible to survive on the planets and exploit their resources in the most efficient manner possible is much better. Something more like paraterraforming.
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We will have travel between planets in our solar system within a human lifetime. That means effective use of this solar system must be by one single species. Humans already live here, so "bio-forming" as they called in on Star Trek Voyager, or "paraterraforming" is not practical. It is practical to terraform Mars, Venus, Ganymede, and Callisto. I wouldn't terraform Luna because it's useful to have an airless body that close to the major industrial planet. Mercury has a lot of metals, and the slow rotation rate together with intense solar heat will have concentrated metals into veins. That solar heat can be used to refine ore. Io has active sulphur volcanoes, powered by heat caused by friction in the core from gravitational tides; it's that close to Jupiter. You can't terraform a calm environment with that much energy pumped into the celestial body. Europa may have liquid water oceans under that crust of water ice, which may have indigenous life. With a total of 5 habitable bodies in the solar system, no need to mess with another one. At least not until we're sure there's no life. Titan is the largest moon of Saturn, just too far from the sun. Asteroids don't have enough gravity.
Ok, that leaves us with Earth, 4 terraformed bodies, 2 that are deliberately left airless for industrial use, 1 is a preserve, and everything else can't be terraformed. Sounds like a great solar system to me.
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We will have travel between planets in our solar system within a human lifetime. That means effective use of this solar system must be by one single species. Humans already live here, so "bio-forming" as they called in on Star Trek Voyager, or "paraterraforming" is not practical. It is practical to terraform Mars, Venus, Ganymede, and Callisto. I wouldn't terraform Luna because it's useful to have an airless body that close to the major industrial planet. Mercury has a lot of metals, and the slow rotation rate together with intense solar heat will have concentrated metals into veins. That solar heat can be used to refine ore. Io has active sulphur volcanoes, powered by heat caused by friction in the core from gravitational tides; it's that close to Jupiter. You can't terraform a calm environment with that much energy pumped into the celestial body. Europa may have liquid water oceans under that crust of water ice, which may have indigenous life. With a total of 5 habitable bodies in the solar system, no need to mess with another one. At least not until we're sure there's no life. Titan is the largest moon of Saturn, just too far from the sun. Asteroids don't have enough gravity.
Ok, that leaves us with Earth, 4 terraformed bodies, 2 that are deliberately left airless for industrial use, 1 is a preserve, and everything else can't be terraformed. Sounds like a great solar system to me.
Whatever you're taking, I want some of it.
Terraforming is an unpractical waste of resources. All humans have to is subsist from the resources that are available in the solar system in sustainable and rational way. All we need is enough water to drink, enough air to breate, enough food to sustain.
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