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Actually I am speculating that with Automation and 3D printers, it might be possible to mass produce such machines in an off planet location at a relatively low cost. Parts interchangeable.
Have a repair station to salvage parts from broken machines that are going to be junked, and then repair the ones that can be repaired. Use Carbon for parts where possible. Build the machines for a life expectancy, and then use the materials for floating habs, after they are juked, unless they crash.
For power of course solar perhaps or perhaps somehow wind. Part of their task might be to shoot Bullets of CO ice into the Exosphere.
For Extraction from the Exosphere there are many notions already, but I am thinking that since the atmosphere of Venus often has a tail like a comet, an orbiter higher up than you might think, where when not in the tail solar wind is used to add energy to the orbit, and when in the tail collection of atmospheric molecules would be implemented. I am fairly aware of how much energy has to be disposed of for that, but I have some ideas that might be a suitable starting point.
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Any settlement requires resources with which to build. Mars is cold, but has everything. Clouds of Venus do not. Venus has 90% surface gravity, and surface area is 90% of Earth. Mass of nitrogen in its atmosphere is 6 times Earth. But once life consumes nitrogen for protein and DNA, much will be consumed. Basically, amount of nitrogen on Venus is just right. Nitrogen is actually the one thing that Mars has too little of; we can only hope that Mars has deposits of nitrogen compounds in the soil somewhere. Venus has great potential, but you have to be on the surface to make use of it. That's hard with it's current temperature. Biological terraforming will take time, but minimal resources.
Another perspective: mass of Earth's biosphere is 224.5 to 11,480 petagrams, depending which source. The page linked has 2 sources that say 1,841 Pg, and one says 1,855 Pg. Let's use 1,841 since it's median. Elements in biosphere: 39.5% carbon. If you convert that to CO2, it's 2664.5 Pg. That's 2.6645 * 10^15 grams. Mass of Venus atmosphere is 4.8 * 10^20 kg = 4.8 * 10^23 g. So we can lose a lot of CO2. Let's see how that works for nitrogen.
0.5% of Earth's biosphere is nitrogen @ 1,841 Pg = 9.205 * 10^15 grams. Venus atmosphere has 3.5% N2 by volume. We could work out proportion by weight, but mass of Venus' atmosphere is approximate anyway. So 0.168 * 10^23 g N2. Hmm. Ok. So Venus could afford to lose a fair bit.
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Don't forget, most of the CO2 on Terra is locked up in carbonate rocks. Once you've finished terraforming Venus, carbonate rocks are going to form, so you need enough CO2 to make sure not all of it is taken.
"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony
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True. I guess whoever is running things will have to decide when it's time to stop. I will say though that if you reduce the pressure on the surface, I would expect the body of the planet to shed even more voltile materials.
For my part though I choose to see Venus not as a planet gone wrong, but perhaps as a big bowl of pudding. If you once have floating habitats, perhaps you are happy with that for thousands of years.
If it is cooled and you eventually add liquid water to the surface, it will cause an alteration of processes I think, explosive volcanic eruptions perhaps. The existing mountains I believe are much taller than would be propper for that environment, the rocky materials being stiffer due to a lack of water. And then if plate tectonics were to start up presumably quakes. I'm not sure the surface would be a great place to dwell, except for required functions such as mining.
So I see a terraformed surface as a very secondary objective. Capturing the atmosphere and using it to a good end being the primary. But that's just my preference.
Last edited by Void (2014-10-29 06:19:18)
Done.
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Is it ok if I use your term "a topopolis" Karov?
From the thread: ""Terraforming" the Asteroid Belt by Tom Kalbfus"
So, rather ambitious, but still, how about a mostly Carbon Toroid, porous, not particularly pressurized, but by methods enriched with atmospheric gasses in it's interior.
With some tensile strength and compressive strength, just maybe does not have to have the correct orbital energy for the altitude that it dwells at.
The atmospheric and solar wind molecules which impinge on it providing both drag and in the case of solar wind thrust. Thrust by sails deployed appropriately to either thrust with photons, or solar wind itself.
And of course you could use electrified tethers either up or down, to either generate electricity or thrust. Unlike a space elevator, however, the severing of one tether is not a disaster. Tethers can also draw ions up from below if you use the correct current flow. Therefore the body of the device does not have to be a low risky altitude.
Seems to me that there is enough thrust to compensate for atmospheric drag already spoken of here, but of course more conventional thrust methods could be employed such as Ion thrusters, but I don't think they are needed. But also maybe the toroid might have magnetic and electrical stimulations, to provide thrust, where the toroid is like a rotor in an induction motor, and the Solar wind and atmospheric plasma like the stator. And then there could be the inch worm method, where the toroid is has movable motorized elements that act against each other and so displace mass which I think might also potentially generate thrust.
So then from atmosphere for building materials, you have Carbon, Plastics, and Sulfur (Which is a metal in a vacuum I have read).
And nothing would stop you from capturing asteroids, or importing materials from Luna or Mercury.
I am of course intending that the exposure to atmosphere will be very rarified, and perhaps in the case of Venus, only encountered on the leeward side (The solar wind being the reference).
And I am thinking of using Adsorption in the Carbon, particularly if it is cold, and some parts will be.
Concentrating the molecules can be by cold and heat processes, or you might also consider flowing currents. For water, it is possible to attract positive ions with a negative charge.
By way of static methods, you would then have a bottle charged inside to an even higher negative voltage, so that the ions attracted would form a skin. An atmosphere held by electrostatic force, and electrostatic condensation.
And then a mechanical pump to pump that skin of gas into a container, and neutralize it's electrical charge.
Of course the interior of the toroid would be a passageway in a circle, and place where suited persons could work, and also their habitats could be inside of it or outside.
So then Venus has a major export. Mined atmosphere, some bound for Mars perhaps. Maybe a tropical Mars in the end after all.
Last edited by Void (2014-10-31 10:38:55)
Done.
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If the planet can be shaded with a sunshield and temperature reduced to 230K, then most of the CO2 in the atmosphere will liquify forming a deep ocean on the surface. This would gradually seep into the crust through fissures and would react with metal oxides in the crust. It would also cool the crust by evaporation. Sulphuric acid would likewise react with surface minerals yieling water and sulphates, once temperatures had declined low enough for it to rain out on the surface.
A sunshield large enough to shade all of Venus would weigh tens of millions of tonnes. It would need to be correctly counterweighted to balance sunlight pressure against the suns gravity. But the scale of engineering is in the same range as some of the O'Neil colony concepts discussed here. The surface would no doubt require decades if not centruries to cool down, but would be habitable in simple tent domes once pressures had declined to a few bar. Maybe a project for the 22nd or 23rd century, when Mars is substantially colonised and space manufacturing is mature.
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Well that may be true, but it would require a culture I don't think the present form of human could generate.
If you could mine the atmosphere of Venus, then terraforming may pay it's own way. But investing massive efforts for a payoff that would come a very long time later is not a business model I am familiar with. Certainly I don't think any economic system of the 20th or 21st century would have worked that way.
And anyway, why not harvest the atmosphere? That's a lot of Carbon which might be quite useful to the human race if it were taken into space.
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Oh, and I forgot to mention that if you have a ring partially powered by solar wind that also gently touches the atmosphere, then you have a means to change the rotation of Venus. You could either make it tidal locked, or increase the spin. If tidal locked, then with other components in place perhaps it would be possible to cause a continuous CO2 rain on the dark side in higher levels of the atmosphere which would bring cold down to the lower levels. Potentially making areas of the surface more thermally compatible with mining, and also causing a quicker cool down. Getting rid of the stratification problem.
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The limits of terrestrial resources and economics shall constrain the potentials of engineering and science for a long time to come. Getting to a place beyond that requires that we make use of the quick, the cheap and the dirty (like the good, the bad and the ugly....) in the here and now. Some of the prerequisites for human habitation at Venus need to take place before anyone sets up a colony and other stuff can wait until later. The quick and dirty modifications should be deployed first. Venus needs a magnetic field and some spin and perhaps a different ordering of its mass (too much atmosphere, too much crust -- a stagnant lid). It needs angular momentum.
The Q&D method would be to attach ion propulsion to certain NEO's and NVO's and clean up our neighbourhood (that's the political sales pitch) by lobbing them at Venus. I read the retrograde spin of Venus as meaning that it got hit hard enough to invert its poles -- like Uranus got hit hard enough to tip it over 90^ before its moons had formed and Earth got hit hard enough to tip it from 5^ (the plane of the lunar orbit) to 23^. Venus did a 180. Hitting Venus with an iron-nickel asteroid will NOT be pretty. We shouldnt do it unless we are prepared to chase down loose shrapnel which could threaten Earth. But if we could strike it near a pole with a steep but glancing blow, we could conceivably tilt it around again and give it some torque too. It would *add* heat in the short term, but also crack the stagnant lid and release heat and also lift some atmosphere into space. Adding mass to Venus should also add to its diameter and gravity. With a longer time horizon, we could also move some asteroid belt ice worlds towards Venus and import water -- same method of ion propulsion and patience.
[color=darkred][b]~~Bryan[/b][/color]
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Given that we're very unlikely to be inhabiting the surface until at least a few centuries have passed, staying in aerostats instead, changing the rotation isn't particularly important. Besides, a slow rotation is actually quite valuable on Venus, because it allows permanent cloud cover at the subsolar point, keeping it cool.
We don't need a magnetic field for radiation protection, either. Maybe for retaining water. The thing that needs to happen to make it much easier to colonise is simply the mass importation of water, to dilute the acid and make it much easier to grow colonies.
"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony
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I think that ultimately Venus could be more rewarding than Mars. I believe our gravity well to be biologically important beyond the mere impediment it presents to lifting ourselves off Earth. Microgravity (Moon, Mars, Ceres, ISS), ionising radiation and the dearth of magnetic fields are bigger issues than atmosphere and chemistry. I say this because issues of element abundance and chemistry are easier to deal with on the scale of human colonies than systemic issues like gravity and cosmic rays, which require planetary scale solutions.
Anyone spending a long time on Mars probably cannot withstand a return to Earth, biologically. And any children born on Mars will never see Earth -- our gravity will crush their bones. It is a one-way trip. The gravity of Venus and its proximity to Earth allow for two-way traffic.It's too bad Earth is the largest terrestrial planet in our system -- if we had a 2x or 3x Earth mass planet here, it would be the obvious destination.
We can get established on Mars rapidly, but only lightly. Venus will ultimately have a higher capacity for our presence.
Anywho, I doubt very much we could do anything to make conditions on Venus worse than they already are! Lobbing iron-nickel meteors at Venus is about more than just its tilt, rotation or fields. Adding mass to the planetary core should crack the stagnant lid crust into plates and release heat. A sufficiently massive impactor should blow off some atmosphere, which is all to the good.
[color=darkred][b]~~Bryan[/b][/color]
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I'm saying, we *need* the slow rotation, if we want to actually terraform it.
I expect we're going to be able to solve the bone loss issues (if there even are any) long before terraforming Venus becomes feasible...
"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony
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Anywho, I doubt very much we could do anything to make conditions on Venus worse than they already are!
I've lived long enough to realize, no matter how bad things get, they can always get worse.
Moving a planet is too big. The mining industry today has shown how to move an entire mountain; it's done one truckload at a time. You don't move a mountain to the outskirts of a city, then mine there. You mine ore in place where it is, bringing the workforce to the mine site. Asteroid mining will be done the same; mine in place, don't move the asteroid. And Venus will be terraformed where it is. We can convert the atmosphere, but forget moving the planet.
I posted my ideas on the first page of this discussion thread.
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StarDreamer wrote:Anywho, I doubt very much we could do anything to make conditions on Venus worse than they already are!
I've lived long enough to realize, no matter how bad things get, they can always get worse.
Moving a planet is too big. The mining industry today has shown how to move an entire mountain; it's done one truckload at a time. You don't move a mountain to the outskirts of a city, then mine there. You mine ore in place where it is, bringing the workforce to the mine site. Asteroid mining will be done the same; mine in place, don't move the asteroid. And Venus will be terraformed where it is. We can convert the atmosphere, but forget moving the planet.
Was someone suggesting we move the planet?
[color=darkred][b]~~Bryan[/b][/color]
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I'm saying, we *need* the slow rotation, if we want to actually terraform it.
I expect we're going to be able to solve the bone loss issues (if there even are any) long before terraforming Venus becomes feasible...
Re: needing slow rotation - sorry, this does not compute... Explain?
Re: bone-loss issues ..... Children born on Mars will not have bone-*loss* issues -- they will be born with bone density appropriate for that gravity and "upgrading" them to Earth levels shall be quite difficult!
[color=darkred][b]~~Bryan[/b][/color]
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Was someone suggesting we move the planet?
Changing rotation or changing orbit, either way you're moving a very big object.
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I expect it will be far easier to modify someone who is used to 0.38g to handle 1g than it will be to terraform Venus...
Re. rotation period and habitability, there was a study a while ago that looked at the effect of a slow rotation - apparently it results in permanent cloud cover at the subsolar point, shielding it and thus cooling the planet.
"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony
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StarDreamer wrote:Was someone suggesting we move the planet?
Changing rotation or changing orbit, either way you're moving a very big object.
What about simply using solar collectors to collect the energy from the Sun and then using that energy collected to generate artificial sunshine? Since Venus gets twice as much sunlight as the Earth, we only need a process which collects the Solar energy and converts it to artificial sunshine with 50% efficiency. We could direct the artificial sunshine to give the surface of Venus a 24-hour day, a 365 day year with four seasons. And hydrogen imported from Pluto can be used to create oceans for Venus.
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The panels could be placed at geo orbit and given a spheric shape to allow an artificial 50% block per meter when alternating a panel to no panel configuration on that frame work to support them. The power could be used to power an orbiting station that is behind the sun shield.
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We could direct the artificial sunshine to give the surface of Venus a 24-hour day, a 365 day year with four seasons.
No need for a 365 day year. That's what Earth happens to have due to its orbit. Human females have a menstrual cycle 21 to 45 days in young women and 21 to 31 days in adults. Average is 28 days, very close to the Moon's synodic period of 29 d 12 h 44 min 2.9 s. That was due to night time illumination by moonlight. Today the menstrual cycle has been synchronized to the modern 7-day work week. Again, human biology adapting to practical necessity. That's the only cycle that matters. Humans do not have any need for length of year to be a particular number of days.
When I took psychology in first year university, the professor played a number of videos. One showed a study on work hours. A mine had swing shifts, and every time shifts changed the workers were much less productive. The researcher found workers could live a 25-hour day. They would wake up an hour latter each day, until the last day of the shift they would wake up just in time to go to work. Then the shift would change so they wake up hours before their shift. Swing shifts were adjusted to match this cycle. As long as workers scheduled sleep time by this cycle, they were happy, healthy, and productive. In fact he found workers were more healthy and productive than a normal 24-hour day. So we don't have to duplicate Earth.
Northern Alaska above the arctic circle has 24/7 sunshine in summer, and 24/7 dark in winter. People adapt.
Many food crops do not require seasons. Others do. Many do not require day/night cycles. Others do. Many crops are most productive in a greenhouse with 24/7 illumination, although the direction of light has to change. So put the light on a track that slowly moves back and forth. You can buy such a mechanism at greenhouse supply stores today. A store in my neighbourhood has one in their front display window. And Biosphere2 found trees require stress of wind for branches to grow strong. They had branches literally fall off from their own weight. The solution is large fans to blow on trees. Illumination and temperature changes for crops are done for a single greenhouse, not anything planet-wide.
That said, high altitude winds are powered by temperature difference caused by the extremely slow rotation period. Venus synodic period is 583.92 days, while its orbital period is 224.701 days. Reflecting sunlight to the night side of Venus could relieve the temperature difference between day and nigh, slowing winds. However, reflecting that much sunlight would warm the planet. It would have to be matched with day side sunshades. But that could make the reflectors easier: a ring of steerable reflectors in orbits with inclinations that shade equatorial, tropical, and mid-latitudes.
But is it necessary? Could cities on Venus just use artificial light during the long night? Store solar power during daylight? Sounds easier than a cloud of mirrors to fundamentally change the day/night cycle.
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I think mirror arrangements are complicated, simply generating the artificial sunlight however you want it is much simpler once you block the natural sunlight from reaching Venus. The area around Venus received more than enough sunlight to power artificial sunlight generation, and if you can do that, you can create artificial season and day and night. Because Venus' actual rotation is slow, this would affect the wind patterns. Probably the winds would go less to the east and west and more to the north and south. Air would rise from the equator and proceed north moving only slightly to the east, and when the air cooled it would descend moving north and slightly to the west, and I believe there would be three convection zones leading to the poles in each hemisphere. With artificial sunlight, artificial "moonlight" can also be provided which approximates a lunar cycle. The Sun my itself would provide solar tides with high tide corresponding to noon and midlight while low tide corresponds to twilight, but of course since were using artificial daylight the high tide and low tide would correspond to a natural Venusian day. So if the tide goes out, it stays out for a long time, it is not a daily event unlike on Earth.
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I would use the solar collected from the on orbit sun shield and beam it to a wave generator as well as to a mountian top blower fans system to create artificial convection flow. The tidal effects can be created by lockes and pumping to raise water levels allowing to back flow to simulate a rising tide all from the excess solar being collected in orbit.
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I've argued before, just design cloud layers to control heat. For Venus, start terraforming with genetically engineered single cell organisms that thrive in the clouds, but convert CO2 into something solid that can precipitate out. Precipitate has to be something stable in current conditions, and won't poison soil once terraforming is complete. As pressure and CO2 drop, temperature will drop. Once rain starts to fall on mountain tops, seed the ground. Start with endolithic bacteria; that's bacteria on Earth that produce acid to dissolve channels in rock. Their channels are close enough to the surface that remaining rock is translucent, letting light it. The rock tunnel protects them from predators, or whatever eats bacteria. But the channels start the process of decomposing rock, and roots of plants can grow into them, anchor points. Lichen grows on rock with those channels. Then pioneering plants, etc.
But I would design cloud layers to control heat form sunlight, not any sort of on orbit sun shield. During the long night, use light bulbs. Modern LED lights, of course.
And Venus doesn't need tides, either. That's another cycle on Earth. Life has evolved to make use of it, but can live without.
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Well unless the organism can stay aloft for very long periods of time all by itself unaided or by some sort of solar plane then there is no chance for any such life to teraform the atmosphere as far as I can see.....
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Earth has something called "aerial plankton". It's a collection of life forms in our atmosphere. Among them are bacteria that form flaps in their cell walls that they flap like wings. They don't exactly fly, but can control their movement. They're so small they drift in air currents. They can ride thermal air currents like a glider to say aloft. And single cell organisms have something called a "taxis": single cell equivalent to instinct. They can fly toward simple things, such as seeking air currents to stay aloft. They can sense air temperature, humidity, smells. I suggest engineering them to seek an updraft when too hot, a down draft when too cold, and seeking water in clouds when thirsty. One nutrient they will need, that does exist but rare in clouds of Venus, is phosphoric acid. They'll need it as as source of phosphate for DNA or RNA. The organisms may seek upper clouds for sunlight when it gets too dark, and seek phosphoric acid to multiply.
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