Floating Cities On Venus

Geoffrey.landis writes "Some of you may have heard me talk about colonizing Venus. Well, for those who haven't, Universe Today is running story about floating cities on Venus. It's a reasonable alternative for space colonies — after all, the atmosphere of Venus (at about 50 km) is the most Earth-like environment in the solar system (other than Earth, of course). '50 km above the surface, Venus has air pressure of approximately 1 bar and temperatures in the 0C-50C range, a quite comfortable environment for humans. Humans wouldn't require pressurized suits when outside, but it wouldn't quite be a shirtsleeves environment. We'd need air to breathe and protection from the sulfuric acid in the atmosphere.'"

Comments

One question

[Tubal-Cain]

And our reason for going to Venus is...?

We can mine the Moon and possibly Mars, but what does Venus offer us? Fuel? I would think it is too hot for mining the surface (robotic miners capable of operating in the heat may not be cost-effective)

Should put something on our moon..

[HomerJ]

I think before we talk about other places, we should probably get the kinks out of everything by putting something on our own moon. A lot of science could be done on a moon base, as well as learning just HOW to put something on another large rock. Lots of reasons why the moon is reasonable:

1) We can already get to the moon. We've been there already. So there's not real jump in tech needed to get there.

2) We can get OFF the moon. The big gotcha with any other landing. Go to Mars? Yeah, could probably get there and land now. Getting off is the hard part. Don't have that problem with the moon.

3) It's speedy to get there. No months of travel. Need to swap people out or something goes horribly wrong--can get there pretty quickly.

Landing on Mars, or floating cities on Venus sound nice. But I'd like to see something a bit more practical in my lifetime of a moon base. It's possible, but there haven't been any major plans to do it.

Re:Modify people, not planets.

[Nicopa]

Don't post Interesting things next to Funny stuff, it confuses the moderators!

Re:Huh?

[jd]

CO2 will react with all sorts of things. The reaction with water produces carbonic acid. Add something alkaline and you get salt + water. Using lime water (a saturated calcium hydroxide solution) is the shortcut version (you get calcium carbonate + water). Once artificial photosynthesis is developed, you can always turn the CO2 into O2 - no shortage of sunlight.

Re:Scuba Gear?

[MadnessASAP]

The suit doesn't need to withstand excessively high or low pressures, it just needs to cover you with something that wont react with the sulfuric acid and provide air. Think of a full body SCUBA suit, no good for work in space but assuming it's made out of the right materials would be quite handy for work on Venus.

Good idea for a 'blimp' space probe

[4D6963]

As many people have pointed out this is obviously infeasible in the foreseeable future (and I believe we're talking at the very least 50 years here), however it may be an interesting idea as a space probe. Technically gets there like a lander probe, except that at some point during the descent after the parachute slowed things down enough the probe would inflate a blimp, and thus float in the atmosphere at tolerable temperatures and pressures.

That would be good to study the atmosphere and also study the surface a bit closer, but what would be really really neat is if it could be the "aircraft carrier" for a UAV or two specially designed to go fly close to the surface, take pictures, and come back for a refuelling, which would be electrical, the source of energy being the solar panels on the blimp (or "solar paint") during day time (which would last I believe about 120 days). It should work fairly well because the skies must be pretty clear at a 50 km altitude, and a blimp can be pretty large so if its entire surface can be covered in "solar paint".. And during night the whole thing could stay idle.

Scientifically this would be very interesting as it would allow to study the atmosphere in situ for an extended period of time (several Venus days) on distances (since the blimp would be carried by the winds, but also the UAVs would explore up and down thereby teaching us so much about the atmosphere, its temperatures, pressures, winds, clouds, chemical compositions) and also we would get to see a lot of Venus' geology thanks to the UAV that would fly close enough to the ground. The question would be how hard would it be to conceive an electrical UAV that could fly in such an atmosphere with the chemistry it has under pressures of up to 95 bars and temperatures of up to 500 C? If it's impossible, would there be any chance to have a camera on the end of a 50 km long cable? (the question being I believe how much would such a long cable weight, considered it can't melt at 500 C or be corroded)

Re:Pure science-fantasy

[zjl56]

Why just limit yourself to creating orbiting or shielded habitats when you can just create the real thing? With self-replicating robots you could throw enough material to Venus to simply sequester the huge amount of C02 and pave the way to a human friendly environment.

All things considered...

[ianm.phil]

I think if humans are going to one day seriously consider terraforming other bodies in the solar system (we've already been doing that to our own for about 12,000 yrs) we ought to start long term terraformation on Venus as soon as possible.

Venus, although nearly identical in gravity, size and distance from the sun to Earth, does not contain any native water and has severe atmospheric issues. Mars, has water and serious atmospheric issues (such as insufficient gravity to retain one) and no magnetic field.

To successfully transform Venus would require first to construct large scale reflectors to reduce the sunlight reaching Venus thus cooling it down, implement a process to sequester the excess carbon in the atmospher, direct large numbers of comets at Venus to introduce sufficient water and then seed the planet with simple anaerobic biotic life to begin to oxygenate the atmosphere. Of course these are outstanding complex and far-future possibilities, but not impossible so far as I know.

In the long run (thousands of years or even tens of thousands), I speculate Venus will likely be Earth II to a greater extent that mars will; it may take Venus a bit longer to become habitable, but once it does payoff in quality of environment would be significant. All the more incentive to encourage twin terraforming endeavors rather than simply focus on Mars.

Battle Angel Alita aka. GUNNM

[Saffaya]

The author, Yukito Kishiro always documents himself a lot before drawing and has the humans on Venus use floating cities in the "Last Order" series of his manga.

http://en.wikipedia.org/wiki/Battle_Angel_Alita:_Last_Order

They did

[Moraelin]

Venus has a magnetic field. It's about 10^-5 that of Earth's but there is one there. If it weren't present, wouldn't the solar winds have stripped the atmosphere from the planet by now?

Well, that's actually the point: they did strip it of all hydrogen, for example. The solar winds ionize the atmosphere something fierce and break the molecules all the time. Heavier elements like C, N and O recombine, but H from (H20 or CH4) escaped into space.

Doing things in the wrong order

[TheLink]

But why bother even to colonize Mars or Venus? That's like trying to run or jump before learning to stand.

What we should do is learn to build practical and sustainable space stations with artificial gravity (the classical spinning wheels, or the tethered ones, or whatever that _works_).

It's not as difficult as colonizing another planet since:

1) you don't have to fight yet another gravity well.
2) you can do it just "outside" your planet - much cheaper.

And you're going to have to do it anyway. If you send people to Venus/Mars - it will take months for them to get there, where will they live during those months? My answer is a space station. Not a NASA Suicide Vessel.

Once you've worked out how to build a practical and sustainable space station, you can use such space stations to go elsewhere in the Solar System - Mars, Venus, the asteroid belts and beyond. There is no _rush_ then. And it stops sounding like a "one way" trip.

To me it is a really stupid idea to try to colonize other planets before we figure out how to do space colonies.

Once people work out how to do space colonies, I bet most colonizers would rather live in a space station than live on inhospitable planets in something that is just as restrictive as a space station ( if not more so - it's trapped on the planet and can't move) - it's not like you'd be able to walk outside in Venus without a protective suit. So what's the difference?

If you want to send people on one way trips to other planets, maybe you should start with certain politicians (you could hold a reality show - Vote Them Off The Planet or something), in that case there could be a significant benefit ;).

Anyway, I find it telling that the NASA and other "space" people keep talking about sending humans to Mars without seriously developing and advancing space station technology. So many stupid people making stupid decisions.

Learn to stand first, then walk, then run, then jump. Not the other way round.

Re:Doing things in the wrong order

[RsG]

You can simulate comfortable gravity easily enough on a large station. Coriolis force is less of an issue further out from the center axis. Build yourself a ring or cylinder big enough, and you'd never know the difference.

On a station using centrifugal force (OK, centripetal force for the pedantic), you can even choose the gravity level most appropriate to the task you desire - closer to the axis of rotation for low-G, closer to the outer hull for earth-G. And zero-G is just outside the nearest airlock.

You can't simulate lack of gravity on a planet though. Nor can you change the gravity from whatever the local value is to what you want/need it to be.

Zero-G is advantageous most of the time from a tech perspective (gravity is just another design constraint), and from the perspective of using the station as a jumping off point for the rest of the solar system, since there's no need to climb out of yet another gravity well. The main need for gravity is keeping people's bones healthy, and making sure they can cope with the return home one day - spin gravity will cover these.

Not that those are reasons not to go build aerostats on Venus, but they are strong arguments in favor of orbitals for the nearer future. Plus, if we ever want to tap into the resources of this system, the asteroid belt is our best bet by far, and putting stations out there (either by converting existing rocks, or building completely man-made habs) is feasible.

Re:Doing things in the wrong order

[IICV]

This is actually my personal theory about why aliens have never visited Earth, the Fermi paradox notwithstanding. Assuming no FTL travel, by the time you've got the technology you need to send ships the dozens of lightyears required to explore new stars, you've already got the technology you need to build colonies in interstellar space. After all, once you can last out there for fifty years, you might as well just set up shop and call it home - nevermind exploring all those distant stars.

Re:Doing things in the wrong order

[invid]

There are 3 major disadvantages to space stations: gravity, temperature regulation, and atmospheric pressure. These problems don't exist on Venus City. If we are going to talk about a significant population of humans living off the Earth (I'm talking thousands) I would bet on cloud cities on Venus before space stations. A hull breach on a space station would be a much more significant problem than on the floating city. However, Venus city has 3 major problems: distance from Earth, gravity well, and raw materials. What is needed prior to building Venus City is a space based infrastructure. This would include large space stations, perhaps built along the Stanford Torus model. I don't see those supporting more than a few hundred humans each, though. There could be orbiting space stations around Venus and Skyhooks for transfering raw materials. As far as building materials go, the atmosphere has plenty of carbon so your basic building blocks could be carbon nanotubes (I'm not sure how they hold up against sulfuric acid though). There is no shortage of solar energy at 50k up, you would get almost as much solar power from the clouds below you reflecting sunlight up as you would from above you. You would still need to import oxygen, hydrogen, and a few other important elements. Mercury could be mined and materials sent to Venus. The only alternative to large scale human colonization of space that would allow for Earth gravity and life style would be Oneillian Space stations (think Babylon 5) which I think would be a step up in difficulty.

People ask why should we go into space and try to colonize it. There are 2 good answers: energy and economies of scale. Energy is abundant and cheap in space (in the inner solar system). Once you are established outside of the Earth's gravity well, transportation is really cheap per kilometer traveled. If an economy of scale is built in space, the material needs of humanity would be taken care of in a way that could sustain billions of humans without polluting the Earth. The wealth generated in space could be rained down on the people of the Earth.

Re:Doing things in the wrong order

[Luminary Crush]

I think there is one other significant problem to overcome: radiaton, whether cosmic ray radiation or sunspot/solar storm radiation. In a spacecraft or space station this is a significant problem. On earth we are protected by our magnetic field. Venus doesn't have an instrinsic magnetic field to speak of, but does have an induced magnetic field. This might be an advantage to colonists of a floating Venusian city versus those of a space station. http://www-ssc.igpp.ucla.edu/personnel/russell/papers/venus_mag/

Re:Instant Global Warming

[bytesex]

Couldn't one create a layer of floating trees then, at 50 km above the surface ? All you'd need is a (admittedly very large) grid to walk/root on. The trees would slowly convert all the CO2 to oxygen. How's the sunlight at 50 km above Venus ?

"LV-426 Shake-and-bake" Terraforming...

[MindKata]

"floating trees to convert all the CO2 to oxygen"

You would need to develop a way to filter out the acids but trees on their own, don't seem a likely way to remove that much CO2. However I think you are on to something about finding a way to deal with its CO2. One solution to Venus maybe to engineer a way to deal with its overall chemistry rather than trying to endure its current state. The planet is in some ways similar to Earth, but would require some awesome advances in technology, not least terraforming to alter its chemical composition.

Maybe in the distant future, humans could combine billions of tonnes of lime with an artificially created seawater like solution and then bombard/rain the planet with it, over the course of a few centuries. (Its an idea thats been suggested to deal with CO2 on earth ... http://www.physorg.com/news135820173.html). It would only be a partial solution as its more complex than just CO2, but its a step in the right direction.

Its engineering way beyond anything we could do I guess for many centuries, but its theoretically possible to deal with the CO2, plus it would give us small ocean like lakes over time. Plus once there are more favorable conditions for some life on the surface, then I think plant life, like your ideas about trees, would then add to the process of terraforming the planet. It would be an awesome engineering project.

Re:"LV-426 Shake-and-bake" Terraforming...

[Asztal_]

Additionally, Venus' rotational period is too long. Venusian days are on the order of two hundred and forty Earth days.

Which is one of the really cool things about floating cities. The wind in Venus's upper atmosphere is really fast (up to 95 m/s). A floating city would be pushed along the sky by the wind, making the days considerably shorter.

Re:Instant Global Warming

[crontabminusell]

Yeah, but the sunburn you'd get on mercury would be awesome.

And the radiation burns you'd get from living in the upper atmosphere of Venus would be no less impressive! (at least, I assume you'd get a wicked dose of radiation as Venus lacks a planetary magnetic field)

Hell yes!

[sckeener]

I'm surprised I haven't seen a copy & paste from a wiki...this is my favorite topic and I frequently refer people to this link:
http://en.wikipedia.org/wiki/Colonization_of_Venus#Aerostat_habitats_and_floating_cities

Geoffrey A. Landis has summarized the perceived difficulties in colonizing Venus as being merely from the assumption that a colony would need to be based on the surface of a planet:

"However, viewed in a different way, the problem with Venus is merely that the ground level is too far below the one atmosphere level. At cloud-top level, Venus is the paradise planet."

He has proposed aerostat habitats followed by floating cities, based on the concept that breathable air (21:79 Oxygen-Nitrogen mixture) is a lifting gas in the dense Venusian atmosphere, with over 60% of the lifting power that helium has on Earth.[4] In effect, a balloon full of human-breathable air would sustain itself and extra weight (such as a colony) in midair. At an altitude of 50 km above Venusian surface, the environment is the most Earth-like in the solar system - a pressure of approximately 1 bar and temperatures in the 0ÂC-50ÂC range. Because there is not a significant pressure difference between the inside and the outside of the breathable-air balloon, any rips or tears would cause gases to diffuse at normal atmospheric mixing rates, giving time to repair any such damages. In addition, humans would not require pressurized suits when outside, merely air to breathe and a protection from the acidic rain. Alternatively two-part domes could contain a lifting gas like hydrogen or helium (extractable from the atmosphere) to allow a higher mass density[5].

Cloud-top colonization also offers a way to avoid the issue of slow Venusian rotation. At the top of the clouds the wind speed on Venus reaches up to 95 m/s, circling the planet approximately every four Earth days in a phenomenon known as "super-rotation".[6] Colonies floating in this region could therefore have a much shorter day length by remaining untethered to the ground and moving with the atmosphere. While a space elevator extending to the surface of Venus is impractical due to the slow rotation, constructing a skyhook that extended into the upper atmosphere and rotated at the wind speed would not be difficult compared to constructing a space elevator on Earth.

Since such colonies would be viable in current Venusian conditions, this allows a dynamic approach to colonization instead of requiring extensive terraforming measures in advance. The main challenge would be using a substance resistant to sulfuric acid to serve as the structure's outer layer; ceramics or metal sulfates could possibly serve in this role.

Landis has suggested that as more floating cities were built, they could form a solar shield around the planet, and could simultaneously be used to process the atmosphere into a more desirable form. If made from carbon nanotubes (recently fabricated into sheet form) or graphene (a sheet-like carbon allotrope), the major structural materials can be produced using carbon dioxide gathered in situ from the atmosphere. The recently synthesised amorphous carbonia might prove a useful structural material if it can be quenched to STP conditions, perhaps in a mixture with regular silica glass. According to Birch's analysis such colonies and materials would provide an immediate economic return from colonizing Venus, funding further terraforming efforts.

Some of the difficulties that /. posters have mentioned have been dealt with in the wiki, but there are some others that have not been mentioned that the wiki deals with.

Personally I think the most difficult aspect would be mining the surface (and that is mentioned in the wiki.) Until we get more data I think this is a pipe dream (that I really want to happen.)

Speaking as someone t