Terraforming Venus

[AngelLestat]

Thaaank you. It seems my post was over looked. FORGET TERRARFORMING. Float.. everything.

Sorry Motokid600, I really thoght that I read all the comments before post that. But it seems that I skip yours. Well, like you can see I am agree

AngelLestat, the problem with mining Venus is that it may not be theoretically impossible, but it would be extremely difficult, every probe sent to the surface has been destroyed in minutes, or even before the probe has reached the surface, the best ever managed was just 2 hours, so if we could build something that could withstand the immense environmental conditions, it will be either mega-project to build, or require constant maintenance, it would be hard to see it as a sustainable colony. You could suck the materials you need out of the sky, but you'd would be limited almost exclusively to carbon, maybe you could get enough hydrogen out of the tiny water content (20 ppm) to make hydrocarbons and then plastics.

I know, but the same Goefrey Landis is planning the next mission and already knows how to deal with that.

The important is to keep save all electronic circuits, for that you need to expend extra energy to move the heat out.

Also the circuits are special, they can work at 300 centigrate degrees.

Electronics:

http://solarsystem.nasa.gov/docs/Day1Hunter.pdf

Rover:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090001338_2008047211.pdf

Different rover that use a sail to move over the surface.

http://www.ndtv.com/article/world/nasa-may-send-sail-powered-rover-to-venus-411131

Also the atmosphere of Venus has Oxigen, not much, But plus hidrogen, carbon dioxide and all other elements and plants. We can get all the things we need to survive.

And how much easier is to leave in the clouds than terraforming venus?

A sail blocking all sun light at very close distance is a way to start colling the planet, but then we need to deal with the rotation period, change all the atmosphere gases.

That would take a lot of time and energy.

Instead live in their clouds is something that we can do right now.

Venus atmospheric habitats, bread basket of the solar system? Grow food using carbon extracted from the atmosphere?

Come to think of it, with a 22 hour rotation (of the habitats) and that far from the surface, what would it take to reach orbit from the habitat? Does the superrotation accelerate furthur up?

The winds at that height are pretty constant due to the large day of one size of the planet at the night at the other to stabilize temperatures.

It can be a lot faster or low, but there are not significant changes that we know.

At that speed the floating city would take 96 hours to complete a rotation. This is close to 90m/s, so is only a little help to reach orbit, but the amount of atmosphere that you need to cross is a lot lower, so is a great help.

We need to take into account that send things to venus or vice versa is a lot more easy than mars, first we need less delta V, also the launch windows to venus are 584 days compared to the 780 for mars.

Solar sails behave a lot better close to the sun, so they can be used to transport payload from earth to venus and back without spend any fuel.

[Motokid600]

I thought it cost more Dv to reach inferior planets. The orbital insertion burn is real expensive, no? Less the craft used aerobraking. But I don't think that's a viable strategy in real life. And.. I can't for the life of me picture how solar sails eject the craft from orbit. Maybe deploy them after the burn? I'd think that defeat the purpose though..

[KASASpace]

Solar sails behave a lot better close to the sun, so they can be used to transport payload from earth to venus and back without spend any fuel.

But they're slow.

As said by wikipedia:

"The total force exerted on a solar sail may be around 1 newton (0.22 lbf) or less,[2] making it a low-thrust propulsion system, similar to spacecraft propelled by electric engines."

So, if you want SPEED, get a BIG ONE. A REALLY BIG ONE. Maybe triangles.....?

Of course there isn't a citation, but it only can do so much........ would take forever to break orbit.

http://en.wikipedia.org/wiki/Solar_sail

[Motokid600]

Sorry if it seems I'm derailing the thread, but with a solar sail.. you'd have to deploy it during sunset and retract it before sunrise, no?

...or is only one side if the sail capable of pushing?

[randomness5555]

I'm interested in exploring the idea of how one would terraform venus.

Obvouly, it's not the easiest possible target- lethal pressures, temperatures, acid rain, and so on. But how much of thatt would be solve "simply" by turning off the sun (from the perspective of venus) for a decade or two?

If you put a massive solar sail near the Sol-Venus L1, or closer to venus with some kind of radiation pressure to push it outward (a similar design was suggested for a mars soletta) and venus lost all forms of external heating, the temperature would eventually drop, the weather would calm down, many of the toxic precipitates would condence out of the atmosphere (lowering atmospheric pressure).

However, I doubt that would solve ALL the broblems- it's simply the best start. What would be the next problem, and how would that be best solved?

It wouldn't even have to be that big of a sail if you put it very near the sun. It would have an eclipse effect so long as the sail remained in the right place, blocking loads more light than if it was further away

[K^2]

It wouldn't even have to be that big of a sail if you put it very near the sun. It would have an eclipse effect so long as the sail remained in the right place, blocking loads more light than if it was further away

And it'd stay there because?

[ProjectXMark1]

Anyone mentioned Venus lacking a magnetic field or having a day longer that its year? Those are the real difficulties in making Venus habitable, I suppose the atmosphere of Venus prevents much of the bombarbment of the solar wind out. The challenge would be to get the rotation faster, and the core spinning, and I'm not sure how to execute the second.

[Rakaydos]

Anyone mentioned Venus lacking a magnetic field or having a day longer that its year? Those are the real difficulties in making Venus habitable, I suppose the atmosphere of Venus prevents much of the bombarbment of the solar wind out. The challenge would be to get the rotation faster, and the core spinning, and I'm not sure how to execute the second.

It seems like the best bet is to ignore the surface entirely. The surface may have a year similar to it's day, but the atmosphere's day is only about 2 days long. Airship cities with lots of air-filled domes (that are lighter than venus air and so float) wouldnt actually be that bad a place to live.

[lajoswinkler]

If you have the resources to consider a terraforming plan that binds all the sulphur and carbon out of the Venusian atmosphere, getting hold of a few thousand asteroids containing iron or other materials that corrode easily into solids when exposed to oxygen rich atmospheres should be no problem.

I don't agree. You're equalizing intelligent approach of genetically modified self-replicating organisms with brute force of hauling absolutelly immense amounts of matter into a significantly lower orbit around the Sun.

[Idobox]

As noted, the higher atmosphere is great, and Venus terribly lacks hydrogen.

Which means stations up there would have access to mostly Sulfur and CO2. Plants need significant amounts of hydrogen, so they're out of the question for transforming alone.

I think the best approach would be Von Neuman airships, made mostly of graphene and graphite, and filled with O2. I suppose it's impossible to build a graphene factory out of carbon alone, so you would need to provdie other elements, most likely silicon and metals, either from the surface or from Earth.

Assuming you are able to follow the exponential growth Von Neuman machines are supposed to follow, you would very quickly have a massive industrial compound providing shade and extracting carbon dioxide from the atmosphere.

Now, you would need massive mounts of hydrogen to turn Venus in something that looks like Earth. The best place to mine it would be Jupiter. But going down the atmosphere, storing millions of tons of LH2 and sending them to Venus is far beyond what could be done reasonably with chemical rockets.

If you somehow manage to do it, you would have something for all your extra oxygen to bind with, CO2 and Sulfur to dissolve into, accelerating the atmosphere destruction.

Otherwise, you'll have to hope there are a lot of reduced rocks available to sink all that oxygen.

Finally, you will still have the problem of dealing with the massive amounts of N2. I have no idea for this one.

All in all, staying in the clouds is much easier.

[KASASpace]

Sorry if it seems I'm derailing the thread, but with a solar sail.. you'd have to deploy it during sunset and retract it before sunrise, no?

...or is only one side if the sail capable of pushing?

You would want the sun to hit the sail, but it takes some computing and waiting to get into the right place at the right time. Not to mention the right attitude. But whatever. Only one side for most designs.

[Skyler4856]

And it'd stay there because?

Lagrange point.

[KASASpace]

Lagrange point.

That's what I was thinking.

Are there any stable Lagrange Points between Venus and the sun?

[andrewas]

No, the stable L points are L4 and 5, which are out of line. A shade would have to go in L1, which means its needs to actively control its position. That would be easy enough using radiation pressure from the sun, much like the Soletta from the Mars Trilogy.

[Albert VDS]

Here's a questions for the cloud habitat/city people: Where are you going to get your resources from to actually build this huge structure?

Because nothing will survive long enough on the surface to be able to mine and bringing it with your would cost a lot.

Also, what would a contingency plan look like when your hab "springs a leak" and plummets to the surface?

[KASASpace]

Here's a questions for the cloud habitat/city people: Where are you going to get your resources from to actually build this huge structure?

Because nothing will survive long enough on the surface to be able to mine and bringing it with your would cost a lot.

Also, what would a contingency plan look like when your hab "springs a leak" and plummets to the surface?

It just has to be less dense than the atmosphere below, and that means HUGE.

As towards how to get there, solar sails are actually economical.

For example http://en.wikipedia.org/wiki/Cosmos_1.

100 days accelerating, less than 5 years to Pluto. And no rocket fuel wasted except for the launcher.

Edited February 10, 2014 by KASASpace

[KASASpace]

No, the stable L points are L4 and 5, which are out of line. A shade would have to go in L1, which means its needs to actively control its position. That would be easy enough using radiation pressure from the sun, much like the Soletta from the Mars Trilogy.

With a solar sail that big, it would probably be able to keep itself stable.

although I would recommend something Cosmos 1-esque, in that it can rotate different sections of the sail.

[AngelLestat]

Here is the orignal Geofrey Landis paper about how to colonize venus.

Also mention that is easier to reach the asteroid belt from venus than from earth or mars or from the same asteroid belt. I still need to understand that.

Plus many other benefits to live in the clouds.

I thought it cost more Dv to reach inferior planets. The orbital insertion burn is real expensive, no? Less the craft used aerobraking. But I don't think that's a viable strategy in real life. And.. I can't for the life of me picture how solar sails eject the craft from orbit. Maybe deploy them after the burn? I'd think that defeat the purpose though..

It depends how close their are to its star.

You maybe had that thought from mercury and moho. They are very close, but the worst thing is that you cant not use aerobrake for the lack of atmosphere, Also their low gravity means that you need to cut almost all your velocity to enter in orbit. So you need to make huge burns to brake.

Here I found a deltaV map from mars and venus, and for my surprice the Landis idea its market on the map "landis land" XD

But those 11.6 km/s to launch rockets from landis place seems too much. Becouse venus has only 0,9g and the atmosphere is similar to the earth from that point. So I dont know.

Heres there is another deltav map with more planets.

About aerobraking; is more effiicient at venus than in mars. The sail would detach from the payload before the aerobraking to dodge venus and procede to brake for its own entering in orbit.

But they're slow.

As said by wikipedia:

"The total force exerted on a solar sail may be around 1 newton (0.22 lbf) or less,[2] making it a low-thrust propulsion system, similar to spacecraft propelled by electric engines."

So, if you want SPEED, get a BIG ONE. A REALLY BIG ONE. Maybe triangles.....?

Of course there isn't a citation, but it only can do so much........ would take forever to break orbit.

http://en.wikipedia.org/wiki/Solar_sail

They seems slow, but they are not.

If you make a burn with a rocket, your burn takes 5 or 10 min. After that you had 5 month of travel.

With the solar sail you have constant acceleration those 5 month!

Example:

--------------------------------------------------------------

Nuclear Rocket cargo ship VS Solar Sail cargo ship.

Mission: Cargo Payload: 5T sent, 5T back.

Rocket cargo transfer ship:

We need an amout of deltaV to travel from low earth orbit to low venus orbit and back to earth low orbit (we can not ask to Venusians to produce the amount of proppelent to go back, only to lauch from landis land to low orbit)

3800 (Elo to Vcap) + 2900 (Vlo) + 3500 (Vlo to Ecap) + 3200 (Elo) = 13400m/s

The payload is only taken into acount in (Elo to Vcap) and (Vlo to Ecap), becouse in that point the payload is detach to proceed with aerobrake, (in venus case it will inflate a small hidrogen ballon to float at 50km, which can be collected by the floating city later.

Rocket NERVA engine, isp 1000s --> VE aprox 10000m/s (mass: 1T)

Propellent tank and structure: (mass: 1T)

Using: m0/m1= exp (DeltaV / Ve) lets calculate the mass ratio needed, and we will do it backwards, from finish trip to the start.

3200 (Elo).

m0 / 2000 kg = exp (3200 / 10000) --> m0= 2750 kg (propellent mass: 0,75 T)

3500 (Vlo to Ecap) - 5.4 month trip travel

m0 / 7750 kg = exp (3500 / 10000) --> m0 = 11000 kg (propellent mass: 3,2 T)

2900 (Vlo)

m0 / 5950 kg = exp (2900 / 10000) --> m0 = 7950 kg (proppellent mass: 2 T)

3800 (Elo to Vcap)

m0 / 11400 kg = exp (3800 /10000) --> m0 = 16670 kg (proppellent mass: 5,3 T)

So 5,3 + 2 +3,2 + 0,75 = 11,25 T of propellent that needs to be raised from earth, to do that we can use skylon who has a max payload of 15T (almost the needed).

The skylon spend 220 T in propellent to raise 15T to Elo. If we exclude the 5 T of payload that also need to be raised to the solar sail case, then we would found that the rocket ship needs to spend aprox 160 T extra of propellent to make all the transfer process.

Now I invite you to make the same calculation using normal chemical engines that we use to day. To transport the payload and to raise the propellent needed from earth. I did not, because I do not consider it to be a fair comparison, besides the numbers looks scary.

Solar Sail ship

Sail Material: CNT sheet 0,1 g/m2 (already used by nasa to shield vessels from electromagnetic radiation, also used by defense department to shield and reinforce anything they got)

Reflective surface: aluminum Chemical Vapor Deposition.

Sail dimension: 400mts x 400mts

Sail mass + reflective surface: 20 kg

Structure booms and reiforment: 40kg

Instrumentation, antena, solar panels: 40kg

Deploy mechanism and sail launch structure is detached from the begining and never come back.

Elo flux radiation: 1360w/m2 - Vlo flux radiation: 2660w/m2

Average flux radiation from the sun in the whole trip: 2000 w/m2

Sail Area: 160000 m2

Average radiation collected: 320 MegaWatt.

We only take the 80% of that power due to the 35 degres of incidence angle --> 256 MW

F= 2E/c --> Force= 1,7 Newton

3800 (Elo to Vcap) + 2900 (Vlo) + 3500 (Vlo to Ecap) + 3200 (Elo) = 13400m/s

3800 (Elo to Vcap) 2000 w/m2 average trip.

Mass: 5100kg

Acceleration: 0.00033 m/s2

Time: 4,4 month to reach 3800 m/s2

It can continue accelerating to reduce the arrival time.

2900 (Vlo) Drops payload to aerocapture. 2660 w/m2

Mass: 100kg

Acceleration: 0.028 m/s2

Time: it only takes 1 day to brake.

3500 (Vlo to Ecap) 2000 w/m2 average trip.

Mass 5100kg

Acceleration: 0,00033 m/s2

Time: 4 Month to reach 3500 m/s2 and continue accelerating.

3200 (Elo) Drops payload to aerocapture. 1360 w/m2

Mass 100kg

Acceleration: 0.0145 m/s2

Time: 2,5 days.

Propellent waste: 0.

Arrival Time is similar, maybe 1 extra month for trip.

---------------------------------------------------------------------

I know for sure that it may be better manuvers to do in both cases, and I would love to read them if someone post it. Also please check in case I did a big mistake in my calculations.

I just wanna have some rough numbers to compare. Becouse I was not sure.

Sorry if it seems I'm derailing the thread, but with a solar sail.. you'd have to deploy it during sunset and retract it before sunrise, no?

...or is only one side if the sail capable of pushing?

The most efficient is to have a solar sail that never retracts, becouse in that case your mass increase for all retract and deploy mechanism.

If you wanna cut thrust, you just need to point normal to the sun. And sunrise or sunset only happens if you are in orbit around a planet, but it does not change much the way to operate the sail.

And it'd stay there because?

Because it is a solar sail...

A solar sail with no payload produce so much lift that can counter gravity. So they orbital speed can be lower to match the same angular speed of venus.

And any deviation can be corrected. The problem that needs to be huge, becouse the source of that radiation flux that you need to block is not puntual "sun diameter".

As noted, the higher atmosphere is great, and Venus terribly lacks hydrogen.

Which means stations up there would have access to mostly Sulfur and CO2. Plants need significant amounts of hydrogen,

At surfuce.. In landis land (50km height) there is hidrogen, some water, and oxigen. And plants needs water, no hidrogen. The fact that they extract hidrogen from water is a different thing.

So another reason to not terraform venus from the common point of view. It needs to be terraformed rising their ground to 50km.. This mean floating cities.

Edited February 10, 2014 by AngelLestat

[Idobox]

At surfuce.. In landis land (50km height) there is hidrogen, some water, and oxigen. And plants needs water, no hidrogen. The fact that they extract hidrogen from water is a different thing.

So another reason to not terraform venus from the common point of view. It needs to be terraformed rising their ground to 50km.. This mean floating cities.

Plants are made of hydrocarbons, so they need substantial amounts of hydrogen, usually found in water or nitrates. The atmosphere of Venus contains only 20ppm of water, which is the only significant hydrogen containing molecule there.

For a few airships, that's plenty enough, but that's far from enough to turn a large part of the CO2 to hydrocarbons like plastic or plants.

Here's a questions for the cloud habitat/city people: Where are you going to get your resources from to actually build this huge structure?

Because nothing will survive long enough on the surface to be able to mine and bringing it with your would cost a lot.

Also, what would a contingency plan look like when your hab "springs a leak" and plummets to the surface?

You get plenty of carbon, nitrogen, oxygen and sulfur up there, with a little bit of hydrogen. Oxygen is a lifting gas, graphite and graphene are amazing construction materials.

Sure it lacks silicon and metals, but strip mining the surface is not that difficult. You basically need a bucket hanging from a balloon, high tolerance mechanics and stupid electronics, possibly based on vacuum tubes, or actively cooled, or stored in a big vat of carbonic ice. That's stuff is heavy, of course, but we're talking of in situ resources use, it won't be light anywhere.

If a balloon springs a leak, the gases will mix slowly, giving you time to react an repair. If you have a slight overpressure and reserves of compressed O2/N2 laying around, you can simply keep the thing afloat by pumping more of the stuff in it (N2 is present in the atmosphere and just needs to be separated). Even if it fails, the ship will sink only very slowly.

[brdavis]

Anyone mentioned Venus lacking a magnetic field or having a day longer that its year? Those are the real difficulties in making Venus habitable

The magnetic field isn't needed - even for Earth, with just 1 Atm of N2/O2, the atmosphere (not the magnetic field) is what's shielding out high energy radiation. With no magnetic field over billions of years you can have atmospheric erosion… but that's not really the big problem for Venus

As to the day… there actually are proposals for how to "spin up" Venus (and, for that matter, change its orbit… yes, that's possible, it just ties very large-scale engineering. John Birch did some great work on this, using the same technique to build a habitable 1 G environment over the entire sphere of Jupiter (yes, really), etc.). Getting rid of the atmosphere (will, 98% of it anyway) is tough. The best plan I've seen calls for importing things like Ca from Mercury - you need to pretty much strip-mine Mercury to get enough Ca to lock up Venus's atmosphere however.

For those with access to a good library, see if you can lay hands on Martyn Fogg's "Terraforming" textbook. Put out by the Society of Automotive Engineers (yes, really), this has all the references, works the numbers (energy, not materials, is often the limiting factor), and details the timescales. It does not worry too much with the economics

[KASASpace]

I was referring to the slow acceleration of the sail.

However I posted earlier:

100 days accelerating, less than 5 years to Pluto. And no rocket fuel wasted except for the launcher.

And if you accelerate during 5 months, you'll be heading towards Sedna or some other extreme orbit dwarf planet.

[AngelLestat]

I think is pointless kept talking about terraforming venus directly from the surfuce point of view.

Economics always needs to be had into account in any plan.

Terraforming venus from the common point of view demands astronomical budgets and long long time to see profits (even if this issue is addressed in the distant future). So there is nothing in the world that it would be disposed to make such investment.

But if we change the point of view and we start from its atmosphere, then everything changes.

Is something that we can do RIGHT NOW with normal space budgets, we can see profits in short time (first ones it would be only science related, then we can had many others profits).

With the time a huge colony or many colonies can be floating there. Changing over time the atmosphere components to make them more suitable for our existance.

Using carbon dioxide and sulfure acids to produce materials or elements usefull to us at the same time that we transform/remplace them by oxigen, hidrogen, etc.

It will come a point in the future, that with this low process and other, would be terraforming venus at such great scale, that cities would start to get down in altitude until them reach the ground.

And I think this idea has real value, but this same misconseption that we need to be in the ground is the one that gives more value to mars instead venus. And is a shame that enoght scientist (and comunity) still needs to change their conception to make a good used of their budgets.

Edited February 11, 2014 by AngelLestat

[SargeRho]

And what do you suppose we should do on Venus? It's on the inner edge of the habitable zone, and will much sooner than Earth be scorched by the sun, more so than now.

Mars in turn is close to the outter edge, and as such, will only get more habitable as the sun ages, up to a certain point of course. So it's a waste of time to even try to terraform Venus, which will take much more time and ressources than Mars, too. Warming a planet like Mars is easier than cooling a planet like Venus. Venus may in fact already be too close to the Sun to ever be Earth-like again. And there's the issue of the extremely slow rotation. Mars has a 25 hour day. Venus' days are longer than its years.

Also, what is there on Venus?

CO2 and Sulphuric acid, and hellish heat. So there is no economic benefit to colonising Venus at all. I'd not bother with more than some science-aerostats.

Edited February 11, 2014 by SargeRho

[MrZayas1]

Well if i understand you right, you wish to push venus' orbit farther out to make most of it's bad qualities condense into the ground, here's my input. I'm going to start off by stating that since we know that venus is like living hell, than we need to consider how in the world we would terraform venus in the first place. Venus's atmosphere is made up of sulphiric acid (commonly found in batteries) so just putting something on venus would be extremely difficult as all machinery made out of metal would corrode very quickly, and be extremely inneficient. We would have to do the opposite of mars, and cool the atmosphere, we definitely know how to do this, but it takes an extremely inefficient amount of trouble to do so and would mean we would have to lessen it's already thick atmosphere.

With your idea, it would probably make sense but i highly doubt that it's atmosphere would change except for the elements in it that are already close to solidification or sublimation. Even then we would have a massive amount of work to do. There is no oxygen on venus, if so, miniscule amounts, but the amount of carbon dioxide in venus would pretty much kill plants because there is so much. The sunlight on venus is very dangerous. And the atmospheric pressure is equivalent to that 3,000 feet beneath the ocean, so any structures built on it's surface would have to be incredibly strong. Although this is a great idea, it just ins't practical in science, unless you know I get frozen in cryonics and wake up 1,000 years from now to our superiority of space elements. But like I said this is an extremely expoundable subject and keep up the great thinking! Hope your day goes well!

[radonek]

… Also, what is there on Venus?

CO2 and Sulphuric acid, and hellish heat …

In other words, basic petrochemical resources and free energy. Even if that should mean hauling down heavy metals from asteroids and hydrogen all the from jupiter, venus can easily be THE place to turn resources into real stuff.