Writing Science Fiction Novel about living above Venus in the near Future! Need help with Science!

[todofwar]

36 minutes ago, DerekL1963 said:

The people I know who've thought deeply about this all think that the real bottleneck isn't genetics - it's occupational specialties.   A colony of 500 might only need a neurosurgeon once every two years or so for example...  where does he get his training and experience?  Etc... etc...  With sufficient and proper tech this can be hand waved away of course, but it's something to be aware of.  (The numbers I've seen tossed about to avoid this bottleneck are in the five digit range.) 

Thing is, you don't need brain surgeons, you get a brain tumor you die. Such a colony won't replicate our life style, but it can keep itself going. 

[DerekL1963]

13 minutes ago, todofwar said:

Thing is, you don't need brain surgeons, you get a brain tumor you die. Such a colony won't replicate our life style, but it can keep itself going. 

You get a brain tumor, you die.  You get a serious concussion, you die.  You suffer a fever that causes swelling of the brain, you die.  You...  well, you get the picture.  

And neurosurgeon isn't the occupational specialty.

[todofwar]

2 minutes ago, DerekL1963 said:

You get a brain tumor, you die.  You get a serious concussion, you die.  You suffer a fever that causes swelling of the brain, you die.  You...  well, you get the picture.  

And neurosurgeon isn't the occupational specialty.

Yeah, low life expectancy. Probably close to 50 or 60. But that's not a problem on its own. We got by for a long time without modern medicine.

[radonek]

19 minutes ago, todofwar said:

Thing is, you don't need brain surgeons, you get a brain tumor you die. Such a colony won't replicate our life style, but it can keep itself going.

Thing is, you die, colony loose invaluable specialist.

[DerekL1963]

48 minutes ago, radonek said:

Thing is, you die, colony loose invaluable specialist.

Precisely.  And at the numbers of colonists quoted, and figuring in those too young to have entered the workforce (you're not going to have a modern technological society without education)...  Losing one invaluable specialist, who is probably the only one of his kind in the colony, can be a pretty heavy blow.  That's why the five figure populations I described above - there's a lot of specialties.

[todofwar]

28 minutes ago, DerekL1963 said:

Precisely.  And at the numbers of colonists quoted, and figuring in those too young to have entered the workforce (you're not going to have a modern technological society without education)...  Losing one invaluable specialist, who is probably the only one of his kind in the colony, can be a pretty heavy blow.  That's why the five figure populations I described above - there's a lot of specialties.

Thing is, you can build in redundancy. Let's think about his scenario, not building new just sustaining one or two habitats. You need a couple repair guys, a couple guys in charge of growing food, a couple guys in charge of collecting resources, and a couple guys in charge of refining them. The other parts, like merchants and Lawyers and doctors, are luxuries. Not really needed. If we're talking about a civilization scale place than yes, it will get tough. But if it's just about staying alive? I'd say 500 is plenty. No one got upset at Watney being a Mary Sue, let's say this colony has ten Watnies that are also good at training others to be half Watney. 

[Andrew Zachary Foreman]

3 hours ago, radonek said:

No, OP wants sustainable colony whose inhabitants are content where they are. No outside contact, much less rescue.
 

It needs to be a colony that is 95% sustainable. I am fine if it is slowly wearing down over time as long as that "overtime" period is several decades. Does that make sense? 

 

3 hours ago, todofwar said:

Not sure. You just need a cold bucket basically, things should deposit into it. Google iodine deposition to get a visual of what to expect. 

I checked it out and now I have a visual to work with. I don't know though, the idea is really cool but is it practical? I still think that if it were possible to use such tech you might as well start mining away the peaks. 

 

3 hours ago, DerekL1963 said:

The people I know who've thought deeply about this all think that the real bottleneck isn't genetics - it's occupational specialties.   A colony of 500 might only need a neurosurgeon once every two years or so for example...  where does he get his training and experience?  Etc... etc...  With sufficient and proper tech this can be hand waved away of course, but it's something to be aware of.  (The numbers I've seen tossed about to avoid this bottleneck are in the five digit range.) 

You raise a good point. Nearly all of the colonists are scientists. Blue collar work doesn't play much of a factor on the work force. I have imagined that once kids would get through their primary education they would study under the scientist in their field almost like an apprentice. They would also have a vast database of knowledge to draw on. 

[todofwar]

@Andrew Zachary Foreman might be, hard to say unless you go over there. We've had a few probes survive on a scale of a few hours on the surface, so give some advances and say you can get a decent sized craft to survive half a day. That half a day would have to be spent drilling, and drilling is going to raise your heat faster. But you might be able to haul more total material. There's a trade off somewhere I'm sure. 

[DerekL1963]

1 hour ago, todofwar said:

Thing is, you can build in redundancy. Let's think about his scenario, not building new just sustaining one or two habitats. You need a couple repair guys, a couple guys in charge of growing food, a couple guys in charge of collecting resources, and a couple guys in charge of refining them. 

Where is the redundancy in that scenario?  One generation, and everything is over because you've no teachers.  And you've got nobody in charge of making the stuff all the other guys need to do their jobs.  Nor anyone in charge of managing all the systems.  Or...  well, I shouldn't have to draw you a diagram.  There's a lot of specialties, and keeping them going requires a lot of people.  This is a highly technical society, not log cabins out in the forest.

The only reason such a colony could have 500 people is because it had an enormous technological society feeding it what it couldn't produce or provide locally.  When that support is taken away...
 

1 hour ago, todofwar said:

The other parts, like merchants and Lawyers and doctors, are luxuries.

Are they?  Under your scenario (no doctors) - one failure and you no longer have redundancy, you're one additional failure away from complete failure.  Not a very good situation.

[Scotius]

Take a look at ancient societies. 500 people isolated from other groups would be a tribe - everyone would have basic skills required for day-to-day survival. Building simple shelter, getting food trom the wilds etc. But there would be no scientists, engineers, full time teachers. For that you would need population in the range of (several) thousands. Only then you would have enough workforce and surplus of food and materials to start specialising. Or take a look at current settlements: five hundred people is a small town - enough to work farms, provide workforce and clients for couple of small businesses (gas station, eatery, couple of shops) and have a small kindergarten-school. But you won't have a big factory, research facility or university there.

[DerekL1963]

54 minutes ago, Scotius said:

Take a look at ancient societies. 500 people isolated from other groups would be a tribe - everyone would have basic skills required for day-to-day survival. Building simple shelter, getting food trom the wilds etc. But there would be no scientists, engineers, full time teachers. For that you would need population in the range of (several) thousands. Only then you would have enough workforce and surplus of food and materials to start specialising. Or take a look at current settlements: five hundred people is a small town - enough to work farms, provide workforce and clients for couple of small businesses (gas station, eatery, couple of shops) and have a small kindergarten-school. But you won't have a big factory, research facility or university there.

And those current settlements have something the notional Venus colony does not have - a connection to the outside world.  Things they don't produce come to the town, and specialists they don't have can either come to the town (well drillers say) or they can travel to the specialists (doctors, etc...).  They are not, as the OP desires his colony to be, fully self sufficient.

[kerbiloid]

A colony with a sentient AI overseer, producing all stuff on demand in 3d printers, isolated from atmosphere, recycling every piece of waste, getting C and O from outside (to compensate occasional losses).
No piece of metal will be lost, because all (originally imported) metal things stay home.

So, the only human role in their industry is a customer of vending machine / utilizer (two-in-one).
(As probably in not-so-far future around all over the Earth).

To kill free time they would have non-economical employments. A colony of artists, poets, scientists (hard to imagine, which ones, except linguists). So, liberal arts. (With a statue of Venus in atrium).

(3d printer + vending machine + utilizer) 3-in-1 aggregate represents the natural life cycle of things in the Nature, personified by Venus,  (birth - nourishment - utilization for new rebirth).

Edited September 30, 2016 by kerbiloid

[Scotius]

There are no loss-less closed systems. Even Earth loses volatiles (water and gases) over time. And the smaller the system, the less time it takes to make it unliveable. Sooner or later all machines and combuters will break down, and there will be no materials to repair or replace them.

[todofwar]

1 hour ago, Scotius said:

There are no loss-less closed systems. Even Earth loses volatiles (water and gases) over time. And the smaller the system, the less time it takes to make it unliveable. Sooner or later all machines and combuters will break down, and there will be no materials to repair or replace them.

his scenario only requires them to survive a few decades. You don't need dedicated teachers, an sorrento system will work. And crafting tools will be another specialty sure. Notice I said you need a couple? But there are 500 colonists. Assume 250 of working age. That's enough to have 10 or so guys each in 25 different specialties. That's enough redundancy to keep yourself going for a few decades. I would even say a good chance of going for a few generations. 

[Scotius]

I have another question to OP: what is that colony even doing there? Obviously someone forked up money, materials and effort to build it there - what was the purpose?

[KerikBalm]

On 9/28/2016 at 2:47 AM, Andrew Zachary Foreman said:

3. ... how much mass can a given quantity of air lift, and what would be the pros and cons of helium, hydrogen, and earth air. Should there be any other gases I should consider?

4. Would it be practical to mine resources from mountain tops to fuel an expanding economy? If it wouldn't, what other options would there be? My understanding is that asteroids would be too far away to be practical and that the atmosphere wouldn't have enough elements to meet all of the expected needs.

5. How hard would it be to get water from sulfuric acid?

1&2) I think its been answered already

3) Assuming your ship orbits where the atmosphere is at about 1 Bar, and its a comfortable temperature... ie lets say its close enough to STP.

1 Mol of gas occupies 22.4 liters at STP. 1 mole of Hydrogen masses 2 grams, 1 mol of Helium masses 4 grams, one mole of "earth air" (mostly N2 with some O2 and a smidgen of Ar) masses about 29 grams.

1 mol of venuses atmosphere masses about 44 grams (its 96.5% CO2). The bouyancy is going to be the difference in mass. 22.4 liters of hydrogen will lift 44-2 = 42 grams. The same volume of helium would lift 40 grams. 22.4 liters of earth air will ift 44-29 = 15 grams

Helium is inert, but would still require the lifting envelope to be separate from the inhabited sections, and require an air supply for any crew servicing the lifting envelope. Alternatively one could do 80% helium (by volume) 20% O2 and have no division. The problem with Helium... where do you get it? its only 12 parts per million in the atmosphere of Venus, it would be very hard to resupply the stuff that leaks out.

Hydrogen: only lifts a little better than helium, but you'll have to keep it seperate from the inhabitated spaces. External leaks are not a fire hazard as CO2 is basically inert. It is also hard to come by with HCl and HF combined being much less than 1 ppm in the atmosphere of Venus, and water vapor only comes in at 20 ppm (0.002%). Venus' atmosphere in general is severely lacking in hydrogen due to its lack of a magnetic field and the strong sunlight -> When compounds such as water were split by UV light, no magnetic field would trap the H+ ions released. Much of the hydrogen escaped, as unlike on Earth, chemical bonds weren't really enough to contain it... at least for atmospheric constituents, I guess the surface still has a lot.

Nitrogren+O2 (Earth atmosphere): Pros: Oxygen is easily obtained from CO2, which is 96.5% of the atmosphere. Nitrogen is 3.5% of the atmosphere, which is a lot better than 0.002% for the hydrogen containing compounds, so it wouldn't be too hard to keep the lifting envelope filled. The lifting envelope would also be 100% breathable, with low fire hazard risks - low maintenece and easy to supply. You'd just need ~2.5x more enclosed volume for the same lifting power as He/H2. There's a reason most proposals go with this.

Aside from CO2 (no lifting power), and N2, the next 2 most common gasses in the atmosphere of venus are SO2 (negative lifting power) and Argon (bouyancy = 4 grams per 22.4 L ... much worse than the others)

Pure O2 as some have suggested would lift less than a mixture with N2, and would be an extreme hazard if there is anything flammable in contact. With jsut O2... you'd have to separate the lifting envelope from the inhabited part. Do O2 and N2, have equipment for concentrating the N2 present in the atmosphere of Venus.

 

4) Not very practical... At the surface its not an atmosphere per se... its neither gas nor liquid, but a super critical fluid. Its very dense. Some of the early probes had their parachutes fail, and survived impact because the "atmosphere" is just that dense. There is an extreme wind gradient between the surface and ~50km... so there would be *a lot* of tension on any connection between th airship and the surface. Any cable will need to not only withstand the high temperatures, but also have an extremely high tensile strenght as well. Even at the highest mountain, you need something that will operate at ~380C/~650K. I don't think it would be very practical. Winds decrease farther away from the equator, so it may be more practical at the poles (the surface temperature won't noticably change though)

A note on even the "slow" surface winds: "The winds near the surface of Venus are much slower than that on Earth. They actually move at only a few kilometres per hour (generally less than 2 m/s and with an average of 0.3 to 1.0 m/s), but due to the high density of the atmosphere at the surface, this is still enough to transport dust and small stones across the surface, much like a slow-moving current of water."

"The winds quickly decrease towards the higher latitudes, eventually reaching zero at the poles."

On the polar vortices: "The linear wind speeds are 35–50 m/s near their outer edges and zero at the poles"

Mining at the poles at least gets around the wind issue. Those wind speeds are stronger than similar speeds on earth because of the atmospheric density.

5) Don't bother, just get the water directly:

Quote

Sulfuric acid is produced in the upper atmosphere by the Sun's photochemical action on carbon dioxide, sulfur dioxide, and water vapour.^[39]Ultraviolet photons of wavelengths less than 169 nm can photodissociate carbon dioxide into carbon monoxide and atomic oxygen. Atomic oxygen is highly reactive; when it reacts with sulfur dioxide, a trace component of the Venusian atmosphere, the result is sulfur trioxide, which can combine with water vapour, another trace component of Venus's atmosphere, to yield sulfuric acid.

CO₂ → CO + O

SO₂ + O → SO₃

SO₃ + H₂O → H₂SO₄

The H2SO4 basically forms by reacting with the SO2 with water vapor, just use the water vapor from the start.

Quote

I also plan to utilize a GMO bacterium that breaks down CO2 into energy and oxygen. Do you think that is feasible? 

Absolutely not, not unless you want perpetual motion machines. Burning Carbon and Oxygen produces energy... its basically the entire basis of coal power (and oil, but oil has more hydrogen, and energy also comes from H+O -> H2O).

It takes energy to break CO2 into C and O. No near future GMO is directly capable of this reaction, nor would it be feasible as that wouldn't help the bacteria grow at all.

A cyano bacteria can make use of the CO2 though, if you also give it water.

***NOTE*** Plants/Algae/Photosynthetic life does not take the carbon from CO2 and release oxygen. The oxygen that plants produce comes from WATER.

CO2 is combined with hydrogen to create hydrocarbons, like glucose. That hydrogen comes from water, which is split and H2O is released:

2 H₂O + 2 NADP⁺ + 3 ADP + 3 P_i + light → 2 NADPH + 2 H⁺ + 3 ATP + O₂

Now you may not the over all equation implies some O comes from CO2: 6CO2 + 6H2O ------> C6H12O6 + 6O2

Since 12 O are released, and water could only supply 6. Note that this is the *net reaction* You actually split more H2O than that, but you regenerate some H2O in the next step:

3 CO₂ + 9 ATP + 6 NADPH + 6 H⁺ → C₃H₆O₃-phosphate + 9 ADP + 8 P_i + 6 NADP⁺ + 3 H₂O

So, From CO2, one O goes into the hydrocarbon, and 1 O combines with H2O to produce water, which can later be split to produce O2. There is nothing we know of in Biology that can directly release the O from CO2 to make Oxygen. Thus there will be no GMO in the near future capable of doing this.

[peadar1987]

14 hours ago, radonek said:

Couldn't one extract moist by piping hot, dense air upwards? Also, some bonus energy from thermal difference. If it were just enough to make operation sufficient, that would be great. How about making whole habitat vertical to make most of thermal/pressure differences?

This is pretty similar to Ocean Thermal Energy Conversion technology on earth. It's theoretically possible, but your energy density isn't great. You would also run into problems with wind shear putting lots of stress on your structure if you were to do it in the atmosphere

14 hours ago, radonek said:

We are not talking an airship but damn floating city. Workshops, factories, farms… If colony is to be self sustainable, it have to be able to produce it own spare parts. That means either  very advanced technology (replicators, nanomachinery, etc…) or just plain industrial base. So yes, processing huge amount of outside air is exactly the thing in my mind.  I would even take it farther - process even more air, make lots of surplus water and use it as coolant for surface machinery. I would not dare to call it "mining", but if one could cool a probe long enough to grab something from surface, that would solve a lot of problems.
 

It's just a gut feeling, but I strongly doubt it is possible to build a floating city that large. The bigger the city, the larger the stresses you're going to impose on it from things like wind loading. It's going to be very difficult to stop something like that from breaking apart. Not to mention the complexity of actually building such a thing in the atmosphere of Venus.

[Scotius]

Why would someone build something so large on Venus? You can't mine anything there, there is only so much science you can do without exploring the surface extensively. Carbon industry? It can be placed anywhere else at lower cost and less risk. A relatively small scientific outpost makes sense, but full scale self-sufficient base housing hundreds of people long-term? Why?

Edited September 30, 2016 by Scotius

[Andrew Zachary Foreman]

4 hours ago, Scotius said:

I have another question to OP: what is that colony even doing there? Obviously someone forked up money, materials and effort to build it there - what was the purpose?

Everyone has raised good points. I want to explain the proposed timeline more thoroughly than I have. Hopefully, this will enable you guys to see what I need a little clearer. 

1. Around 2050-2060 A colony is formed in Venerian atmosphere mostly as a scientific experiment. 

2. Between 2050 and 2080 the Colony is developed to the extent that it can now fully support 500 people with aid from Earth. Colony somehow must become economically viable. I am looking for explanations as to how this would be done. I heard CO2, but there might be better ways. 

3. Around 2080 all communication is suddenly and dramatically cut off. At this time all spaceships would have been in transit. There is no way to escape Venus, Venerians must either learn how to survive or all die. (This is crucial to the plot so we really can't do too much with this.) 

4. Eventually, contact with other humans will be restored. This will open up the opportunity to get resources that can enable them to repair their ship and anything else they need. This should happen around 2130-2140. 

Highlights, Fully staffed and fully supported up until 2080. Everyone in the colony would have had advanced education and been in the age range of 20-40. Given several decades, successive generations would have been born. Once primary education is completed children would have been apprenticed to learn a specific science. Since this would require everyone to be a teacher of their trade this would negate some of bottleneck population problem. Furthermore, I imagine that the way in which people today are utilizing resources like YouTube and Khan Academy to learn could be used to a much higher degree aboard the airship in the event that the last person of a skilled trade met an untimely death. 

 

2 hours ago, KerikBalm said:

1&2) I think its been answered already

3) Assuming your ship orbits where the atmosphere is at about 1 Bar, and its a comfortable temperature... ie lets say its close enough to STP.

1 Mol of gas occupies 22.4 liters at STP. 1 mole of Hydrogen masses 2 grams, 1 mol of Helium masses 4 grams, one mole of "earth air" (mostly N2 with some O2 and a smidgen of Ar) masses about 29 grams.

1 mol of venuses atmosphere masses about 44 grams (its 96.5% CO2). The bouyancy is going to be the difference in mass. 22.4 liters of hydrogen will lift 44-2 = 42 grams. The same volume of helium would lift 40 grams. 22.4 liters of earth air will ift 44-29 = 15 grams

Helium is inert, but would still require the lifting envelope to be separate from the inhabited sections, and require an air supply for any crew servicing the lifting envelope. Alternatively one could do 80% helium (by volume) 20% O2 and have no division. The problem with Helium... where do you get it? its only 12 parts per million in the atmosphere of Venus, it would be very hard to resupply the stuff that leaks out.

Hydrogen: only lifts a little better than helium, but you'll have to keep it seperate from the inhabitated spaces. External leaks are not a fire hazard as CO2 is basically inert. It is also hard to come by with HCl and HF combined being much less than 1 ppm in the atmosphere of Venus, and water vapor only comes in at 20 ppm (0.002%). Venus' atmosphere in general is severely lacking in hydrogen due to its lack of a magnetic field and the strong sunlight -> When compounds such as water were split by UV light, no magnetic field would trap the H+ ions released. Much of the hydrogen escaped, as unlike on Earth, chemical bonds weren't really enough to contain it... at least for atmospheric constituents, I guess the surface still has a lot.

Nitrogren+O2 (Earth atmosphere): Pros: Oxygen is easily obtained from CO2, which is 96.5% of the atmosphere. Nitrogen is 3.5% of the atmosphere, which is a lot better than 0.002% for the hydrogen containing compounds, so it wouldn't be too hard to keep the lifting envelope filled. The lifting envelope would also be 100% breathable, with low fire hazard risks - low maintenece and easy to supply. You'd just need ~2.5x more enclosed volume for the same lifting power as He/H2. There's a reason most proposals go with this.

Aside from CO2 (no lifting power), and N2, the next 2 most common gasses in the atmosphere of venus are SO2 (negative lifting power) and Argon (bouyancy = 4 grams per 22.4 L ... much worse than the others)

Pure O2 as some have suggested would lift less than a mixture with N2, and would be an extreme hazard if there is anything flammable in contact. With jsut O2... you'd have to separate the lifting envelope from the inhabited part. Do O2 and N2, have equipment for concentrating the N2 present in the atmosphere of Venus.

 

4) Not very practical... At the surface its not an atmosphere per se... its neither gas nor liquid, but a super critical fluid. Its very dense. Some of the early probes had their parachutes fail, and survived impact because the "atmosphere" is just that dense. There is an extreme wind gradient between the surface and ~50km... so there would be *a lot* of tension on any connection between th airship and the surface. Any cable will need to not only withstand the high temperatures, but also have an extremely high tensile strenght as well. Even at the highest mountain, you need something that will operate at ~380C/~650K. I don't think it would be very practical. Winds decrease farther away from the equator, so it may be more practical at the poles (the surface temperature won't noticably change though)

A note on even the "slow" surface winds: "The winds near the surface of Venus are much slower than that on Earth. They actually move at only a few kilometres per hour (generally less than 2 m/s and with an average of 0.3 to 1.0 m/s), but due to the high density of the atmosphere at the surface, this is still enough to transport dust and small stones across the surface, much like a slow-moving current of water."

"The winds quickly decrease towards the higher latitudes, eventually reaching zero at the poles."

On the polar vortices: "The linear wind speeds are 35–50 m/s near their outer edges and zero at the poles"

Mining at the poles at least gets around the wind issue. Those wind speeds are stronger than similar speeds on earth because of the atmospheric density.

5) Don't bother, just get the water directly:

The H2SO4 basically forms by reacting with the SO2 with water vapor, just use the water vapor from the start.

Absolutely not, not unless you want perpetual motion machines. Burning Carbon and Oxygen produces energy... its basically the entire basis of coal power (and oil, but oil has more hydrogen, and energy also comes from H+O -> H2O).

It takes energy to break CO2 into C and O. No near future GMO is directly capable of this reaction, nor would it be feasible as that wouldn't help the bacteria grow at all.

A cyano bacteria can make use of the CO2 though, if you also give it water.

***NOTE*** Plants/Algae/Photosynthetic life does not take the carbon from CO2 and release oxygen. The oxygen that plants produce comes from WATER.

CO2 is combined with hydrogen to create hydrocarbons, like glucose. That hydrogen comes from water, which is split and H2O is released:

2 H₂O + 2 NADP⁺ + 3 ADP + 3 P_i + light → 2 NADPH + 2 H⁺ + 3 ATP + O₂

Now you may not the over all equation implies some O comes from CO2: 6CO2 + 6H2O ------> C6H12O6 + 6O2

Since 12 O are released, and water could only supply 6. Note that this is the *net reaction* You actually split more H2O than that, but you regenerate some H2O in the next step:

3 CO₂ + 9 ATP + 6 NADPH + 6 H⁺ → C₃H₆O₃-phosphate + 9 ADP + 8 P_i + 6 NADP⁺ + 3 H₂O

So, From CO2, one O goes into the hydrocarbon, and 1 O combines with H2O to produce water, which can later be split to produce O2. There is nothing we know of in Biology that can directly release the O from CO2 to make Oxygen. Thus there will be no GMO in the near future capable of doing this.

Given the scarcity of water vapor how would you propose we harvest it in the first place? Developing incredibly heat and pressure resistant equipment for mining at the poles would still be essential. Could this be done? 

 

In conclusion, is it absolutely necessary that they find a way to collect additional resources from the ground?

[Scotius]

Only viable way to make such setup economical is chemical industry. Extraction of carbon, sulphuric acid and nitrogen. Maybe mass production of carbon half-products (fibers, graphene, nanotubes etc). The problem is, all that stuff is pretty common elsewhere. Carbon is fourth most abundant element in Universe, sulphur, oxygen and nitrogen aren't rare and hard to get either. Interplanetary civilisation would find all that stuff in asteroids, and won't bother with lifting it from the bottom of venusian gravity well. Or in a pinch get it from Earth itself.

Maybe tourism? How many people would want to pay hefty sum of money to watch toxic clouds on another planet?

[Andrew Zachary Foreman]

2 minutes ago, Scotius said:

Only viable way to make such setup economical is chemical industry. Extraction of carbon, sulphuric acid and nitrogen. Maybe mass production of carbon half-products (fibers, graphene, nanotubes etc). The problem is, all that stuff is pretty common elsewhere. Carbon is fourth most abundant element in Universe, sulphur, oxygen and nitrogen aren't rare and hard to get either. Interplanetary civilisation would find all that stuff in asteroids, and won't bother with lifting it from the bottom of venusian gravity well. Or in a pinch get it from Earth itself.

Maybe tourism? How many people would want to pay hefty sum of money to watch toxic clouds on another planet?

Since this is science fiction, what if we say that a rare element or something like else along those lines was discovered on Venus? This could make the planet seem a lot more welcoming. Also, our understanding of the planet is still premature enough that it wouldn't be unfair to rule this out as a possibility.  

[DerekL1963]

1 - a scientific experiment to find out...  what?

3 - There were no ships inbound to Venus they could ride home?  That makes no sense whatsoever.

You haven't solved the bottleneck problem - because your system is designed to produce scientists.  The bottleneck isn't in luxuries - it's in necessities, the engineers and technicians needed to operate and maintain the machinery.
 

12 minutes ago, Andrew Zachary Foreman said:

Since this is science fiction, what if we say that a rare element or something like else along those lines was discovered on Venus? This could make the planet seem a lot more welcoming. Also, our understanding of the planet is still premature enough that it wouldn't be unfair to rule this out as a possibility.  

An element that's in high demand (and completely irreplaceable) that suddenly become rare enough on Earth that they think it's worth it dredge it from the surface of Venus...   And yet it's not found someplace easier to get to like the Moon or the asteroids?  That's a tall order for a McGuffin.

[Scotius]

Handwavium, eh? OK, what about this - Earth develops enough to actually be able to build a space elevator. But it requires monstrous amounts of nanotubes woven into a giant cable segments hundreds of kilometers long. And in a surprising twist upper layers of venusian atmosphere allow for production of nanotubes in bulk from readily available CO₂. Is that better?

[KerikBalm]

Quote

1) Given the scarcity of water vapor how would you propose we harvest it in the first place?

2) Developing incredibly heat and pressure resistant equipment for mining at the poles would still be essential. Could this be done? 

1) As mentioned before, the easiest way is just to condense it from the atmosphere. Luckily the water vapor is a lot easier to capture than the helium, even though both are in similar abundance (double digit parts per million)

Note that you don't "filter" gases like this. What you'd probably be doing is called "fractional distillation"

https://en.wikipedia.org/wiki/Fractional_distillation

Its how we produce Xe from our atmosphere now, and its how you'd take the N2 out of the atmosphere as well. I suppose some chemical methods may work too (chemical methods won't work for noble gasses like Helium though)

Essentially, the gas condenses or freezes out at different temperatures. The CO2 will freeze out at -78 C, leaving a mixture that is mostly just nitrogen. I don't know if further purification would be neccessary. The Sulpher dioxide would condense out at this temperature as well, leaving just N2, some harmless inert gasses (Argon, Helium, Neon), and then theres the

HCl and HF... which are quite bad, but those combined are less than 0.7 ppm, so maybe it wouldn't be too bad... plus they're quite reactive so chemical purification should work. HF should condense to a liquid by -78C, and be easy to remove. HCl would unfortunately still be a gas. You could cool it down to -85 C to get that to liquify if the small amount of HCl is a problem and can't be removed by other means... The N2 won't liquify until -196 C, so you'll separate the components quite well by just cooling below -78 or -85C

Long before you cool it down to -78, the water will have condensed out. Cooling a million liters of venusian atmosphere will leave you with the equivalent of 20 liters of water vapor... this is the vapor... thats about 1 mol of water, or a measly 18 grams of it. You'd need to cool about 50 million liters of venusian atmosphere to get a liter of liquid water. You would need excellent water recyling. It doesn't sound so bad if you use cubic meters, then its only 50,000 cubic meters... Thats actually just a cube of 36.8 meters... Just cool it down and scrape the condensation of the sides, and repeat, you'll get almost a liter each time.

Run the "AC" constantly on air you suck in, and water will start condensing, just minimize losses, and you should be fine.

My guess is that they'd mostly "run the AC" for the purposes of water extraction, cooling air more to get the N2 would require much smaller volumes (as its 35,000 ppm compared to H2O at 20 ppm). The same equipment can get you the N2 and the H2O. Keep in mind that you only need to cool the Venusian air a couple/few dozen degrees to get the water to condense, but you need to cool the air by about 100C to get the N2.

 

#2) I really have no idea.

[todofwar]

5 minutes ago, KerikBalm said:

1) As mentioned before, the easiest way is just to condense it from the atmosphere. Luckily the water vapor is a lot easier to capture than the helium, even though both are in similar abundance (double digit parts per million)

Note that you don't "filter" gases like this. What you'd probably be doing is called "fractional distillation"

https://en.wikipedia.org/wiki/Fractional_distillation

Its how we produce Xe from our atmosphere now, and its how you'd take the N2 out of the atmosphere as well. I suppose some chemical methods may work too (chemical methods won't work for noble gasses like Helium though)

Essentially, the gas condenses or freezes out at different temperatures. The CO2 will freeze out at -78 C, leaving a mixture that is mostly just nitrogen. I don't know if further purification would be neccessary. The Sulpher dioxide would condense out at this temperature as well, leaving just N2, some harmless inert gasses (Argon, Helium, Neon), and then theres the

HCl and HF... which are quite bad, but those combined are less than 0.7 ppm, so maybe it wouldn't be too bad... plus they're quite reactive so chemical purification should work. HF should condense to a liquid by -78C, and be easy to remove. HCl would unfortunately still be a gas. You could cool it down to -85 C to get that to liquify if the small amount of HCl is a problem and can't be removed by other means... The N2 won't liquify until -196 C, so you'll separate the components quite well by just cooling below -78 or -85C

Long before you cool it down to -78, the water will have condensed out. Cooling a million liters of venusian atmosphere will leave you with the equivalent of 20 liters of water vapor... this is the vapor... thats about 1 mol of water, or a measly 18 grams of it. You'd need to cool about 50 million liters of venusian atmosphere to get a liter of liquid water. You would need excellent water recyling. It doesn't sound so bad if you use cubic meters, then its only 50,000 cubic meters... Thats actually just a cube of 36.8 meters... Just cool it down and scrape the condensation of the sides, and repeat, you'll get almost a liter each time.

Run the "AC" constantly on air you suck in, and water will start condensing, just minimize losses, and you should be fine.

My guess is that they'd mostly "run the AC" for the purposes of water extraction, cooling air more to get the N2 would require much smaller volumes (as its 35,000 ppm compared to H2O at 20 ppm). The same equipment can get you the N2 and the H2O. Keep in mind that you only need to cool the Venusian air a couple/few dozen degrees to get the water to condense, but you need to cool the air by about 100C to get the N2.

 

#2) I really have no idea.

Don't need to cool all that air down at once, just need to run it through a cold trap, at least for the water. A continuous flow system will net you all you need. The acids will dissolve into the water, and the HF will chew through most things and is one of the few chemicals i refuse to work with because its so toxic, so that will need to be separated somehow. 

For something on this scale zeolites might be the better way to get notrogen, they can be designed to trap certain gasses.