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In terms of human habitation, the big advantages of Venus' atmosphere are: 1. It has essentially Earth-normal gravity. Zero-G long-term is a death sentence f

In terms of human habitation, the big advantages of Venus' atmosphere are: 1. It has essentially Earth-normal gravity. Zero-G long-term is a death sentence for humans. The long term effects of Martian gravity are unknown. It seems safe to assume that Venus gravity is fine. 2. It is protected from impact and radiation by an atmosphere in a way that Mars or asteroids never will be. 3. It has an essentially limitless supply of carbon, oxygen, nitrogen, and sulfur available to it. 4. It is reasonably well-positioned for solar power. 5. It is relatively temperate. 6. Low pressure differential between inside a habitat and outside of one means that leaks are less severe and containment breaches are easier to react to. But there is at least one huge disadvantage: 1. Everything besides carbon, oxygen, nitrogen, and sulfur needs to be imported, either from a fantastically hostile surface, or down through reentry into an atmosphere in a deep gravity well and rendezvousing with an aerostat. That disadvantage is a pretty goddamn significant one for human habitation. But it's not a disadvantage for long-term robot probes, and it's... less... of a disadvantage for a minimal-population scientific base.

ohitsdom 12y ago
Succinct and accurate summary.
astazangasta 12y ago
Your disadvantage 1 is the result of a failure of imagination. The vast majority of life on Earth is built from nothing but carbon, oxygen,nitrogen, hydrogen, etc., and human life requires not much else. We could easily subsist on just these elements.
- aetherson 12y ago
  Note that "hydrogen" lists among your rather crucial elements necessary for life, and does not feature in Venus' atmosphere in significant quantities. And, more so, while human life per se requires very small amounts of non-carbon, oxygen, and hydrogen elements, human technology requires very large amounts of non-carbon, oxygen, and hydrogen elements.
  - stcredzero 12y ago
    AFAIK, sulphuric acid is present in the Venusian atmosphere in large enough quantities to cause obscuring clouds. Though, I imagine that equipment to harvest the hydrogen from those clouds would end up being quite expensive. (Given my limited chemistry knowledge, I'd guess that large amounts of silicon would be involved in their manufacture.) There are also significant amounts of hydrogen sulfide. (Which could be quite a complication for human settlers as well.) EDIT: FTFA -- "Moreover, while both planets boast ample amounts of volatile life-sustaining materials like hydrogen, carbon and nitrogen, only Venus’s dense atmosphere would be helpful in shielding human colonists from the harsh assault of solar radiation."
- rgbrenner 12y ago
  Sure.. except, nature has conveniently put those elements into forms we can use. So until we're able to do that ourselves, that's a disadvantage we'll have to deal with. It's less a failure of imagination, and more a failure of our current level of technology.
- vacri 12y ago
  'Subsisting' does not include 'artificial cities floating in the sky'. Similarly, getting a computer to run on nothing by carbon, oxygen, nitrogen, hydrogen and sulphur, none of which are metals or semiconductors, is a massive task, if doable at all.
  - stcredzero 12y ago
    I don't think getting things from Venus orbit down to human friendly aerostat altitude is going to be an insurmountable problem. When sending things into the Venusian atmosphere, you can always take advantage of aero-braking. Then, the aerobraking equipment can itself be taken apart and used. Running an economy on mostly carbon, oxygen, nitrogen, hydrogen, and sulphur would make for an interesting hard sci-fi book!
    - seanflyon 12y ago
      Any real colony needs to be mostly self sufficient (hopefully entirely self sufficient) so the problem is not getting materials down from orbit, but up from the surface.
      - stcredzero 12y ago
        In a far-seeing, long term analysis, I don't think we should limit "colonies" to discrete heavenly bodies. Long term, we should consider the complex of Venus, Mercury, and Venus-crossing asteroids as a local resource pool. The notion that a single planet has to be largely self-sufficient as an independent unit is a bit of prejudice that comes from our upbringing on Earth. On Earth, in terrestrial economic terms, it's generally relatively expensive to get things off the planet and back onto its surface in one piece. For this reason, we think of planet Earth as a practical (if not absolute) boundary for economic transactions and resources. In the larger context of a solar system spanning society, it's costly in absolute terms by current-day Earth standards, but in the larger context, it's also relatively cheap to ship things down into the Venusian atmosphere from Mercury, Venus-crossing asteroids, and even Mars. In fact, one can make it materially inexpensive by applying lots of energy, which shouldn't be nearly as expensive by that point. It's probably true that Earth's gravity well will limit trade of material goods between itself and the rest of the solar system. But there's no reason that a solar system spanning culture couldn't exist as a largely separate entity. I suspect people will live out there just for the idea of it, and that nation-states will help in the endeavor just to propagate their own cultures.
stcredzero 12y ago
> reentry into an atmosphere in a deep gravity well and rendezvousing with an aerostat. What about rendezvous of a rotating tether with a hypersonic craft? We can make cables now that are strong enough to support a "rotorvator" rotating tether at the lengths required. What about very large, very long, aerostat facilities that are mostly huge electromagnetic cannon for launching robot hypersonic craft? These could be built to withstand 1000's of gravities, to allow ballistic launch from high altitiude facilities, but have a return flight profile suitable for passengers and other fragile cargo. We could also have Venusian hybrid jet/rocket hypersonic craft that are fueled with liquid carbon monoxide. This technology could mean that getting to the colonized Venusian ecosphere would be a lot cheaper than getting off of it, if you are a biologically standard Homo sapiens. EDIT: So, how this would play out in a cyberpunk space opry: Many people choose to emigrate to Venus because of the price of labor there. However, economic pressures cause a large fraction of the Venusian populace to undergo radical cybernetic modification, because it opens up job opportunities on the hostile surface and makes it less expensive to get back to Earth and other parts of the Solar System. This pathway is chosen by desperate and marginal people, who often take advantage of the radical modification surgery to shed their old identities. Voila! Gritty Sci-Fi cyberpunk future based on chemistry, physics, and economics. EDIT: It turns out that the energy cost for getting between Mercury and Venus isn't so large. Also, there are a good number of Venus-crossing asteroids. So anything you can get from a carbonaceous chondrite asteroid shouldn't be precious to the point of rarity on Venus. Among other things, both silicon and hydrocarbons could be mined in industrial quantities. EDIT: An interesting Selenian Boondocks blog post about the chemistry and physics of extracting various resources out of the Venusian atmosphere at human-aerostat altitudes! http://selenianboondocks.com/2013/12/venus-isru-condenseables/ http://selenianboondocks.com/2013/12/venus-isru-condenseable... EDIT: An interesting idea for surface resource extraction -- bombard the surface with rocks from orbit, with the intention of creating clouds of dust which can be harvested by specially designed airships. Though this is inefficient materially, it might result in far less wear and tear on equipment, which gets to remain at higher and friendlier altitudes. EDIT: Carbon monoxide and sulphuric acid can be used as a fuel/oxidizer pair in a rocket engine! Both can be condensed right out of the Venusian atmosphere. Granted, these are a bit cantankerous even as far as rocket fuels go.
fredfoobar 12y ago
Why aren't people thinking about sending various robots/devices that could terraform planets before humans going in to live there? Is this something that is impossible to do/imagine? what am I missing?
- stickfigure 12y ago
  Alternatively, why aren't we talking about venusforming humans? All space operas seem to start with the earth-standard human in a suit. Compared to geoengineering a whole earth-standard atmosphere, bioengineering an intelligent organism that can thrive in nonearth environments seems fairly sane. There's a social taboo against human genetic experimentation (hell, some people seem to struggle with vegetables) but that will eventually pass.
  - clavalle 12y ago
    >bioengineering an intelligent organism Or just engineering some. Biological organisms seem overly tuned to their environment and complex ones need a supporting biological ecosystem to thrive (so far that we've seen). It may be more effective to get robotics to our level and expand intelligence into the galaxy 'synthetically'.
    - knodi123 12y ago
      once you've gotten to the tech level where you can artificially engineer a lifeform advanced enough to do something useful, but hardy enough to survive venus- by that point I'd say the distinction between robot and organism would be pretty blurry. ;-)
    - hereonbusiness 12y ago
      I don't get why more people don't think this way. Humans as they are today will probably never be able to thrive in space or even on other planets similar to earth, that is without a lot of genetic engineering or something of that sort. Create intelligent self replicating machines and a large part of the problems related to space travel just disappear. If creating an AGI is possible I would be surprised if the universe isn't already full of artificial life.
jccooper 12y ago
Mining the surface is required; importing any significant quantity of material from Earth is a non-starter. Unless you can come up with something insanely valuable to export to Earth, any planetary colony has to be almost-entirely self-sufficient. Interplanetary transit is too long, and too expensive. (This is true on Mars as well, and probably Luna and asteroids as well, though you might find some edge cases there due to lesser gravity or greater proximity.) The pressure on the surface is that of about 3000 feet of water, so that's not too bad, and the reducing atmosphere can be handled, but the temperature is tough. Still, with practice, you could probably build such machines. Dunno how you make electronics survive long term at ambient 465 °C (oil wells have a hard time with electronics at much lower temps) but some combination of active cooling, limited duration, and novel fabrication should be possible. Perhaps the easiest solution is to load up your Venus Mining Hopper with a whole bunch of liquid nitrogen, extracted from the atmosphere and compressed and liquefied using solar power falling on your floating platform. It deflates its balloon and drops to the surface, and starts scooping up material into its hopper as the LN2 boils off, cooling the electronics and other temp-sensitive systems. (These are buried in lots of insulation.) When the hopper is close to full, you start venting the N2 into the balloon, and the whole system takes off again, to rendezvous with a solar-powered tug to pull it to your ore-processing factory. That may be a long haul, because the upper atmosphere of Venus moves at 100m/s. Maybe you design your system to stay on the ground long enough for the platform to come back around the planet, a mere 4-5 days. Or maybe it just takes a big bite and goes straight back up so it doesn't get too far behind. So maybe doable, but it makes the hurdle for setting up a self-sustaining colony much higher. Not that it's a much lower hurdle anywhere else.
- kaybe 12y ago
  The temperature is a reason why Venus would be a good place to test out the ideas for climate manipulation we have collected so far. A first step could be to lower the CO2 content (my current favourite would be to release engineered bacteria into the atmosphere that can bind the Cs and after death collect it on the ground), and enhance the albedo (so more sunlight is reflected away). In the longterm we will need climate control anyway since Earth's climate is somewhat unstable (global warming is just as bad as a new ice age, which, extrapolating from the past, would be about due by now, if not for mankinds influence). Testing it on a planet we are not critically dependent on should be a better strategy. Geologically, Venus is very different from Earth due to the lack of water (which enables plate tectonics and all its implications). Some changes we can make would even influence the geology. (Hm, I wonder what would happen if we dumped enough water meteroids.. ) All of this of course premises a lack of preexisting life with planetary ownership rights and no natural reserve rules (which we kind of have at the moment - http://planetaryprotection.nasa.gov/about http://planetaryprotection.nasa.gov/about).
JulianMorrison 12y ago
1g at 1 atmosphere has disadvantages. Namely: to get off the planet, you will need a fully fuelled multistage rocket with an almost identical profile to rockets you'd launch from ground level on Earth. Something like a Falcon 9. That's a bit heavy to lug all the way from Earth. Bonus: you have to launch by dropping it into a hell-cauldron of poison gases miles above a crushing, melting surface, better hope you don't have an engine out, because there are no launch aborts or do-overs. Then you have to fly it out through a hot corrosive acid atmosphere which I don't imagine would be very friendly to machined aluminum.
- fenaer 12y ago
  Why not a space plane? Surely reaching orbital velocity on a platform that is already moving at a decent speed around the planet would ease it somewhat?
- stcredzero 12y ago
  > 1g at 1 atmosphere has disadvantages. Namely: to get off the planet, you will need a fully fuelled multistage rocket with an almost identical profile to rockets you'd launch from ground level on Earth. Condense Carbon Monoxide and Sulphuric Acid from Venus's atmosphere for use as fuel and oxidizer in a hypersonic rocketplane that tops out at about Mach 11. Have the rocketplane rendezvous with the end of a rotating tether. http://www.tethers.com/papers/HASTOLAIAAPaper.pdf http://www.tethers.com/papers/HASTOLAIAAPaper.pdf No multi-stage rocket. No expendable launch vehicles. That's probably not the actual solution, but it shows that you don't have to have a Falcon 9 equivalent. > Then you have to fly it out through a hot corrosive acid atmosphere which I don't imagine would be very friendly to machined aluminum. It should be possible to condense HF out of the Venusian atmosphere, so we should be able to manufacture PTFE locally with input from non-Earth resources. (Mining chondrites from Mercury and Venus-crossing asteroids.)
- pavel_lishin 12y ago
  Not quite an identical profile; it's not quite 1g, since Venus is less massive, and you're already quite a ways off the surface. It's still not trivial, but it's not like there are a whole lot of do-overs when launching valuable human cargo from Earth, either. (What happens if the space shuttle's engines go awry? Everyone on board dies, and everyone on the ground speculates as to whether they died within 30 seconds, or survived to hit the ocean.)
crusso 12y ago
down through reentry into an atmosphere in a deep gravity well The good news there is that space elevator climbing efficiencies could be gained without having to worry about flying some kind of aircraft.
shirro 12y ago
> 4. It is reasonably well-positioned for solar power. A day on Venus is 224.65 earth days long. That is a long night so perhaps the solar power thing isn't that clear cut.
- andrewflnr 12y ago
  You're moving with the wind, though, not the surface.
andyjdavis 12y ago
> It has an essentially limitless supply of carbon, oxygen, nitrogen, and sulfur available to it. Are you able to provide a rough summary of how the quantities of these materials compare with the quantities available on earth? It wasn't that long ago that humans spoke about things like the number of fish in the sea, the ability of the earth's atmosphere to absorb waste gases etc as being effectively infinite until we eventually discovered that this was unfortunately not true. It is just something that pops into my head whenever the word unlimited, infinite or limitless get used when talking about energy, resources and so on.
- TeMPOraL 12y ago
  As long as we're talking about one mostly self-contained city, resources available will likely be infinite from practical point of view. The problem with Earth is that there are 7 billions of us living now; our impact thus becomes significant.
- starwaver 12y ago
  but it did last for thousands of years, pretty sure we'll get a lot more efficient at resource management by then.
  - andyjdavis 12y ago
    It would be nice to hope so but I'm actually unsure. We are becoming more efficient with resource management because our resources are increasingly constrained. If those constraints are removed, over the course of a few generations, it would be easy to slide back to doing whatever is fastest and cheapest (might be the cleaner way, might not be).
- deleted 12y ago
  [deleted]

ohitsdom 12y ago

Succinct and accurate summary.

astazangasta 12y ago

Your disadvantage 1 is the result of a failure of imagination. The vast majority of life on Earth is built from nothing but carbon, oxygen,nitrogen, hydrogen, etc., and human life requires not much else. We could easily subsist on just these elements.

aetherson 12y ago
Note that "hydrogen" lists among your rather crucial elements necessary for life, and does not feature in Venus' atmosphere in significant quantities. And, more so, while human life per se requires very small amounts of non-carbon, oxygen, and hydrogen elements, human technology requires very large amounts of non-carbon, oxygen, and hydrogen elements.
- stcredzero 12y ago
  AFAIK, sulphuric acid is present in the Venusian atmosphere in large enough quantities to cause obscuring clouds. Though, I imagine that equipment to harvest the hydrogen from those clouds would end up being quite expensive. (Given my limited chemistry knowledge, I'd guess that large amounts of silicon would be involved in their manufacture.) There are also significant amounts of hydrogen sulfide. (Which could be quite a complication for human settlers as well.) EDIT: FTFA -- "Moreover, while both planets boast ample amounts of volatile life-sustaining materials like hydrogen, carbon and nitrogen, only Venus’s dense atmosphere would be helpful in shielding human colonists from the harsh assault of solar radiation."
rgbrenner 12y ago
Sure.. except, nature has conveniently put those elements into forms we can use. So until we're able to do that ourselves, that's a disadvantage we'll have to deal with. It's less a failure of imagination, and more a failure of our current level of technology.
vacri 12y ago
'Subsisting' does not include 'artificial cities floating in the sky'. Similarly, getting a computer to run on nothing by carbon, oxygen, nitrogen, hydrogen and sulphur, none of which are metals or semiconductors, is a massive task, if doable at all.
- stcredzero 12y ago
  I don't think getting things from Venus orbit down to human friendly aerostat altitude is going to be an insurmountable problem. When sending things into the Venusian atmosphere, you can always take advantage of aero-braking. Then, the aerobraking equipment can itself be taken apart and used. Running an economy on mostly carbon, oxygen, nitrogen, hydrogen, and sulphur would make for an interesting hard sci-fi book!
  - seanflyon 12y ago
    Any real colony needs to be mostly self sufficient (hopefully entirely self sufficient) so the problem is not getting materials down from orbit, but up from the surface.
    - stcredzero 12y ago
      In a far-seeing, long term analysis, I don't think we should limit "colonies" to discrete heavenly bodies. Long term, we should consider the complex of Venus, Mercury, and Venus-crossing asteroids as a local resource pool. The notion that a single planet has to be largely self-sufficient as an independent unit is a bit of prejudice that comes from our upbringing on Earth. On Earth, in terrestrial economic terms, it's generally relatively expensive to get things off the planet and back onto its surface in one piece. For this reason, we think of planet Earth as a practical (if not absolute) boundary for economic transactions and resources. In the larger context of a solar system spanning society, it's costly in absolute terms by current-day Earth standards, but in the larger context, it's also relatively cheap to ship things down into the Venusian atmosphere from Mercury, Venus-crossing asteroids, and even Mars. In fact, one can make it materially inexpensive by applying lots of energy, which shouldn't be nearly as expensive by that point. It's probably true that Earth's gravity well will limit trade of material goods between itself and the rest of the solar system. But there's no reason that a solar system spanning culture couldn't exist as a largely separate entity. I suspect people will live out there just for the idea of it, and that nation-states will help in the endeavor just to propagate their own cultures.

stcredzero 12y ago

> reentry into an atmosphere in a deep gravity well and rendezvousing with an aerostat. What about rendezvous of a rotating tether with a hypersonic craft? We can make cables now that are strong enough to support a "rotorvator" rotating tether at the lengths required. What about very large, very long, aerostat facilities that are mostly huge electromagnetic cannon for launching robot hypersonic craft? These could be built to withstand 1000's of gravities, to allow ballistic launch from high altitiude facilities, but have a return flight profile suitable for passengers and other fragile cargo. We could also have Venusian hybrid jet/rocket hypersonic craft that are fueled with liquid carbon monoxide. This technology could mean that getting to the colonized Venusian ecosphere would be a lot cheaper than getting off of it, if you are a biologically standard Homo sapiens. EDIT: So, how this would play out in a cyberpunk space opry: Many people choose to emigrate to Venus because of the price of labor there. However, economic pressures cause a large fraction of the Venusian populace to undergo radical cybernetic modification, because it opens up job opportunities on the hostile surface and makes it less expensive to get back to Earth and other parts of the Solar System. This pathway is chosen by desperate and marginal people, who often take advantage of the radical modification surgery to shed their old identities. Voila! Gritty Sci-Fi cyberpunk future based on chemistry, physics, and economics. EDIT: It turns out that the energy cost for getting between Mercury and Venus isn't so large. Also, there are a good number of Venus-crossing asteroids. So anything you can get from a carbonaceous chondrite asteroid shouldn't be precious to the point of rarity on Venus. Among other things, both silicon and hydrocarbons could be mined in industrial quantities. EDIT: An interesting Selenian Boondocks blog post about the chemistry and physics of extracting various resources out of the Venusian atmosphere at human-aerostat altitudes! http://selenianboondocks.com/2013/12/venus-isru-condenseables/ http://selenianboondocks.com/2013/12/venus-isru-condenseable... EDIT: An interesting idea for surface resource extraction -- bombard the surface with rocks from orbit, with the intention of creating clouds of dust which can be harvested by specially designed airships. Though this is inefficient materially, it might result in far less wear and tear on equipment, which gets to remain at higher and friendlier altitudes. EDIT: Carbon monoxide and sulphuric acid can be used as a fuel/oxidizer pair in a rocket engine! Both can be condensed right out of the Venusian atmosphere. Granted, these are a bit cantankerous even as far as rocket fuels go.

fredfoobar 12y ago

Why aren't people thinking about sending various robots/devices that could terraform planets before humans going in to live there? Is this something that is impossible to do/imagine? what am I missing?

stickfigure 12y ago
Alternatively, why aren't we talking about venusforming humans? All space operas seem to start with the earth-standard human in a suit. Compared to geoengineering a whole earth-standard atmosphere, bioengineering an intelligent organism that can thrive in nonearth environments seems fairly sane. There's a social taboo against human genetic experimentation (hell, some people seem to struggle with vegetables) but that will eventually pass.
- clavalle 12y ago
  >bioengineering an intelligent organism Or just engineering some. Biological organisms seem overly tuned to their environment and complex ones need a supporting biological ecosystem to thrive (so far that we've seen). It may be more effective to get robotics to our level and expand intelligence into the galaxy 'synthetically'.
  - knodi123 12y ago
    once you've gotten to the tech level where you can artificially engineer a lifeform advanced enough to do something useful, but hardy enough to survive venus- by that point I'd say the distinction between robot and organism would be pretty blurry. ;-)
  - hereonbusiness 12y ago
    I don't get why more people don't think this way. Humans as they are today will probably never be able to thrive in space or even on other planets similar to earth, that is without a lot of genetic engineering or something of that sort. Create intelligent self replicating machines and a large part of the problems related to space travel just disappear. If creating an AGI is possible I would be surprised if the universe isn't already full of artificial life.

jccooper 12y ago

Mining the surface is required; importing any significant quantity of material from Earth is a non-starter. Unless you can come up with something insanely valuable to export to Earth, any planetary colony has to be almost-entirely self-sufficient. Interplanetary transit is too long, and too expensive. (This is true on Mars as well, and probably Luna and asteroids as well, though you might find some edge cases there due to lesser gravity or greater proximity.) The pressure on the surface is that of about 3000 feet of water, so that's not too bad, and the reducing atmosphere can be handled, but the temperature is tough. Still, with practice, you could probably build such machines. Dunno how you make electronics survive long term at ambient 465 °C (oil wells have a hard time with electronics at much lower temps) but some combination of active cooling, limited duration, and novel fabrication should be possible. Perhaps the easiest solution is to load up your Venus Mining Hopper with a whole bunch of liquid nitrogen, extracted from the atmosphere and compressed and liquefied using solar power falling on your floating platform. It deflates its balloon and drops to the surface, and starts scooping up material into its hopper as the LN2 boils off, cooling the electronics and other temp-sensitive systems. (These are buried in lots of insulation.) When the hopper is close to full, you start venting the N2 into the balloon, and the whole system takes off again, to rendezvous with a solar-powered tug to pull it to your ore-processing factory. That may be a long haul, because the upper atmosphere of Venus moves at 100m/s. Maybe you design your system to stay on the ground long enough for the platform to come back around the planet, a mere 4-5 days. Or maybe it just takes a big bite and goes straight back up so it doesn't get too far behind. So maybe doable, but it makes the hurdle for setting up a self-sustaining colony much higher. Not that it's a much lower hurdle anywhere else.

kaybe 12y ago
The temperature is a reason why Venus would be a good place to test out the ideas for climate manipulation we have collected so far. A first step could be to lower the CO2 content (my current favourite would be to release engineered bacteria into the atmosphere that can bind the Cs and after death collect it on the ground), and enhance the albedo (so more sunlight is reflected away). In the longterm we will need climate control anyway since Earth's climate is somewhat unstable (global warming is just as bad as a new ice age, which, extrapolating from the past, would be about due by now, if not for mankinds influence). Testing it on a planet we are not critically dependent on should be a better strategy. Geologically, Venus is very different from Earth due to the lack of water (which enables plate tectonics and all its implications). Some changes we can make would even influence the geology. (Hm, I wonder what would happen if we dumped enough water meteroids.. ) All of this of course premises a lack of preexisting life with planetary ownership rights and no natural reserve rules (which we kind of have at the moment - http://planetaryprotection.nasa.gov/about http://planetaryprotection.nasa.gov/about).

JulianMorrison 12y ago

1g at 1 atmosphere has disadvantages. Namely: to get off the planet, you will need a fully fuelled multistage rocket with an almost identical profile to rockets you'd launch from ground level on Earth. Something like a Falcon 9. That's a bit heavy to lug all the way from Earth. Bonus: you have to launch by dropping it into a hell-cauldron of poison gases miles above a crushing, melting surface, better hope you don't have an engine out, because there are no launch aborts or do-overs. Then you have to fly it out through a hot corrosive acid atmosphere which I don't imagine would be very friendly to machined aluminum.

fenaer 12y ago
Why not a space plane? Surely reaching orbital velocity on a platform that is already moving at a decent speed around the planet would ease it somewhat?
stcredzero 12y ago
> 1g at 1 atmosphere has disadvantages. Namely: to get off the planet, you will need a fully fuelled multistage rocket with an almost identical profile to rockets you'd launch from ground level on Earth. Condense Carbon Monoxide and Sulphuric Acid from Venus's atmosphere for use as fuel and oxidizer in a hypersonic rocketplane that tops out at about Mach 11. Have the rocketplane rendezvous with the end of a rotating tether. http://www.tethers.com/papers/HASTOLAIAAPaper.pdf http://www.tethers.com/papers/HASTOLAIAAPaper.pdf No multi-stage rocket. No expendable launch vehicles. That's probably not the actual solution, but it shows that you don't have to have a Falcon 9 equivalent. > Then you have to fly it out through a hot corrosive acid atmosphere which I don't imagine would be very friendly to machined aluminum. It should be possible to condense HF out of the Venusian atmosphere, so we should be able to manufacture PTFE locally with input from non-Earth resources. (Mining chondrites from Mercury and Venus-crossing asteroids.)
pavel_lishin 12y ago
Not quite an identical profile; it's not quite 1g, since Venus is less massive, and you're already quite a ways off the surface. It's still not trivial, but it's not like there are a whole lot of do-overs when launching valuable human cargo from Earth, either. (What happens if the space shuttle's engines go awry? Everyone on board dies, and everyone on the ground speculates as to whether they died within 30 seconds, or survived to hit the ocean.)

crusso 12y ago

down through reentry into an atmosphere in a deep gravity well The good news there is that space elevator climbing efficiencies could be gained without having to worry about flying some kind of aircraft.

shirro 12y ago

> 4. It is reasonably well-positioned for solar power. A day on Venus is 224.65 earth days long. That is a long night so perhaps the solar power thing isn't that clear cut.

andrewflnr 12y ago
You're moving with the wind, though, not the surface.

andyjdavis 12y ago

> It has an essentially limitless supply of carbon, oxygen, nitrogen, and sulfur available to it. Are you able to provide a rough summary of how the quantities of these materials compare with the quantities available on earth? It wasn't that long ago that humans spoke about things like the number of fish in the sea, the ability of the earth's atmosphere to absorb waste gases etc as being effectively infinite until we eventually discovered that this was unfortunately not true. It is just something that pops into my head whenever the word unlimited, infinite or limitless get used when talking about energy, resources and so on.

TeMPOraL 12y ago
As long as we're talking about one mostly self-contained city, resources available will likely be infinite from practical point of view. The problem with Earth is that there are 7 billions of us living now; our impact thus becomes significant.
starwaver 12y ago
but it did last for thousands of years, pretty sure we'll get a lot more efficient at resource management by then.
- andyjdavis 12y ago
  It would be nice to hope so but I'm actually unsure. We are becoming more efficient with resource management because our resources are increasingly constrained. If those constraints are removed, over the course of a few generations, it would be easy to slide back to doing whatever is fastest and cheapest (might be the cleaner way, might not be).
deleted 12y ago
[deleted]