Venus vs. Mars colonization

[K^2]

1 hour ago, fredinno said:

Wouldn't hydrogen more readily leak through though, or make the balloon more brittle?

You might still want to do maintenance tho.

Helium leaks really well, because it is monoatomic and inert. Hydrogen's interactions are quite a bit stronger. It's still slightly more leaky than Oxygen and Nitrogen, but not to the point where it'd be causing trouble. And the abundance does make it easy to top off any of the lifting structures.

Why would it make anything more brittle? It's not cryogenic LH₂. It's just a gas. And not one that's particularly reactive, so it won't be changing the chemical composition of the walls. Any polymer that will withstand diluted sulfuric acid on the outside will be totally fine with Hydrogen on the inside.

For maintenance, you can totally walk around the interiors of a hydrogen-filled balloon. Just suspend some catwalks inside. The only catch is that you couldn't use any open-cycle breathing system inside. Expelling used air into Hydrogen atmosphere would be very bad, since Oxygen content in that can still be pretty high, and it takes very little to set off Oxygen-Hydrogen mixture. But a rebreather solves this problem. It's a closed system that recycles air by scrubbing CO₂ and adding O₂, much like space ship's life support does. And yes, they make them portable enough for diving, so you can have maintenance crews going in with them without issues.

[Albert VDS]

14 hours ago, K^2 said:

Erm. Why would you want to fix them? The entire city is carried by the winds, so there is no relative wind. Except for light turbulence, it will always be calm weather in the cloud city, so the balloons can be just balloons. Though, I would put them into some sort of semi-rigid grid, so we can attach solar panels on top, and have various service catwalks all over.

You want to be able to fix them because the whole colony depends on it. The balloons don't magically stay up when it sprung a leak until it's fixed.
Having a huge surface area to maintain compared to the livable space is not very efficient and just adds to possible failures.
How would you even be able to check every cm of this huge structure?

And then there is the mass issue, the colony has a mass limit per settlement depending on the carrying weight of the balloons.
You don't have that with a colony on a surface of a planet. On Mars you can have as you like and have more living space.

On Venus the wind would take you were it wants to go. On Mars you could drive your methane(with an oxygen tank) powered rover where ever you want to go.
 

Edited January 15, 2016 by Albert VDS

[DBowman]

5 hours ago, AngelLestat said:

I don't like that base design, I just find exactly what magnemoe was asking (when I was looking something else), so I wanna see his reaction   
On the design, I like more a rigid structure as K2 said, a ellipsoid shape to keep aerodynamic and structure strengh will do the work.. because you want to move that city or outpost to different latitudes once a while.

In a quick read I did not understand how to calculate the scale height, I will see tomorrow if I have time.. it also work to calculate radioactive shielding. 

(long distance between asteroids) I know, that is one of the reasons why the asteroid belt is the worst location to find the next right asteroid.
About safety...

No planet is in that area, that is why jupiter clean all the objects and the same with inner planets.  And I am not saying that you will be hit for a big asteroid.. just a small one will do enough damage. And is just a game of chances..  which is higher there than close to other planets.
The distance is 2,2 to 3,2 AU, this mean 282w/m2 vs 133w/m2 (one side), this has no comparison with venus that you get 400w/m2 (all sides, no need for tracking) inside the clouds and +600w/m2 a little above... 
No to mention 2600w/m2 in venus orbit.
Venus is closer that any other planet to the asteroid belt, and it has higher orbital velocity, so the travel time is lower. You can pick one, use its own ice as propellent and then capture the asteroid using the thick atmosphere of venus..  then is all yours.  Earth can not do aerocapture of asteroids.. it will be too risky.
 

 

Thanks for the diagram - all that juicy mass not at the bottom of a gravity well. Apparently there are 1.7 M > 1 km in diameter, 'average separation' 10x Earth Moon distance. It's probably a power law thing on the sizes, I'm not sure how much of the 'very small stuff' got swept up by the larger ones. I feel like the collision probabilities are probably manageable, either via luck or mobility, I guess we'll find out more either from sims, tracking, or evidence on asteroids we 'investigate'. I feel like it a legitimate risk source that has to be characterized and accounted for, but at the moment I don't know enough to say it excludes asteroids as the most useful resources in the solar system.

Re solar I think at 0.5 bar it's in the clouds so say 400 w/m2, If you din't account for the day/night factor then it looks pretty much like the mid to outer belt, but without the zero-g and no weather material & construction advantage.

Asteroidal material is clearly the way to go for construction of Venus infrastructure that isn't hydrocarbons. The initial encounter setup and aerocapture is 'easy enough' (if the asteroid had the structural integrity to take it...). Raising the periapsis would be the challenge because while you have 'all the time in the world' to setup the encounter you have a limited time to kick the periapsis higher. This might well mean it's more effective to do the refining, and probably manufacture, at the asteroids so you can leave the dross behind and only deltaV the productive mass.

Edited January 15, 2016 by DBowman
oops 0.5 bar is in the clouds

[magnemoe]

6 hours ago, AngelLestat said:

I don't like that base design, I just find exactly what magnemoe was asking (when I was looking something else), so I wanna see his reaction   
On the design, I like more a rigid structure as K2 said, a ellipsoid shape to keep aerodynamic and structure strengh will do the work.. because you want to move that city or outpost to different latitudes once a while.

In a quick read I did not understand how to calculate the scale height, I will see tomorrow if I have time.. it also work to calculate radioactive shielding. 

(long distance between asteroids) I know, that is one of the reasons why the asteroid belt is the worst location to find the next right asteroid.
About safety...

No planet is in that area, that is why jupiter clean all the objects and the same with inner planets.  And I am not saying that you will be hit for a big asteroid.. just a small one will do enough damage. And is just a game of chances..  which is higher there than close to other planets.
The distance is 2,2 to 3,2 AU, this mean 282w/m2 vs 133w/m2 (one side), this has no comparison with venus that you get 400w/m2 (all sides, no need for tracking) inside the clouds and +600w/m2 a little above... 
No to mention 2600w/m2 in venus orbit.
Venus is closer that any other planet to the asteroid belt, and it has higher orbital velocity, so the travel time is lower. You can pick one, use its own ice as propellent and then capture the asteroid using the thick atmosphere of venus..  then is all yours.  Earth can not do aerocapture of asteroids.. it will be too risky.
 

 

Base looks nice, however I would prefer an more sectioned balloon system for redundancy, also the deck looks heavy, why not use an lattice structure. (yes it would increase polygon count a lot I understand)
Benefit is three life support systems and a good placement of runway. 
Don't see how that plane can reach orbit size might fool me but it looks like an fighter jet. 
Even if you use an nuclear jet engine who also work as an nerva you would need an far larger plane.

Assembling the structure will be problematic, you both need thermal protection against the reentry then pop an balloon, now have an service airship grab it and then transfer cargo to main habitat for assembly. 
Again nothing we have much experience in outside of mid air refueling and resupplying warships in sea. 

Sounds like 0.5 bar is better because of temperature, this is no problem for humans, just add an bit more oxygen. It will however require larger balloons, no issues with hydrogen. Only issue might be that it will leak out fast trough an rift being so much lighter. 
---
Solar in deep space has an benefit in that you don't need much structure for it, you could also use mirrors for concentrate it
Anyway you would focus on asteroids close to earths orbit anyway because travel time and dV is lower. 
How will the day/ night cycles be for the Venus cloud base or how long will the night be

 

An asteroid base would be an space station docked to the asteroid more than an surface structure. 

[Spaceception]

My Idea for a dome habitat on Mars:

Location: Crewe crater (Lets just assume it has water, which it probably does): Which is about 3 km across

The dome will encase the entire crater, and will look something like this (Only it'd be a geodesic dome):

Characteristics:

The dome: The domes glass will be made of aluminum glass with interwoven Carbon Nanotubes (For strength) with a layer of liquid water underneath (For radiation protection) And a layer of Ferrofluid on top to keep the dome from collapsing in case of a breach (As well as giving time for the robots to fix it), and will have triangle rail grids for maintenance robots that will repair anything that breaks on the dome.

The floor:

Water will cover 1/3 of the surface, and will be for fish farming.

Plant life will cover 1/4 of the surface

The martian city will cover the remaining 42% of the surface and will hold up to 5,000,000 colonists

The atmosphere:

Atmospheric pressure will be 65% Pressure at sea level, and will have 75% N 22% O2 2.6% Ar .4% CO2

Power:

Solar simply will not work on this scale, so Nuclear will be the only option, and it will be either a Thorium Breeder reactor or (more likely) A Fusion reactor.

Cost: Seeing as how most of the resources will already be on Mars, cost wouldn't really matter, so that brings us to:

Timescale: With constant construction, and lots of robotic helpers working day and night, it will likely take 8-15 years to build, and 2 years to finish (Liquid water, plants, breathable atmosphere, etc, etc).

So what do you guys think? Are any changes needed?

 

Edited January 19, 2016 by Spaceception

[SargeRho]

6 minutes ago, Spaceception said:

(Only, the black bars will be squares not triangles): 

Bad idea. I'm no engineer or architect, but triangles are absurdly strong. And everything else is rather weak. If you want to build a dome, you should build a geodesic one.

Also, initially, a dome is a bad idea because it will get hit by meteors, until Mars has been terraformed to the point of having a thick enough atmosphere.

[Spaceception]

1 minute ago, SargeRho said:

Bad idea. I'm no engineer or architect, but triangles are absurdly strong. And everything else is rather weak. If you want to build a dome, you should build a geodesic one.

Also, initially, a dome is a bad idea because it will get hit by meteors, until Mars has been terraformed to the point of having a thick enough atmosphere.

Alright, triangles then, also, anything that holds a million or more people is going to be at risk, a dome will be better rather than underground, because it'd feel more open, and the colonists won't feel as confined, which is good on the psychology sides of things. And besides, I mentioned maintenance robots that would fix any problems on the dome, as they might arise.

[SargeRho]

If something pierces the dome, it's going to rupture and kill a lot of people very quickly, due to the high pressure difference.

If something flattens a hab, only the people in that hab are going to be killed, not the whole colony.

[Spaceception]

3 minutes ago, SargeRho said:

If something pierces the dome, it's going to rupture and kill a lot of people very quickly, due to the high pressure difference.

If something flattens a hab, only the people in that hab are going to be killed, not the whole colony.

Each triangle would be reinforced, and separated from the other triangle, also, what about Ferrofluid? https://en.wikipedia.org/wiki/Ferrofluid

[SargeRho]

That isn't going to help you against a meteoroids strike, not in the slightest. A rock smacking into the dome at 25000kph is going to rip a sizeable hole in it, no matter what it's built of. You'd need some sort of advanced tracking system that can detect and subsequently deflect them away from the dome. We don't have forcefields, yet.

[Spaceception]

I do agree with your first point, we don't have the materials that would help us deflect meteoroids on Mars, but the odds of something hitting a 3 km dome on a 3400 km planet is very tiny, and it's very unlikely that something considerably big would hit it. And because of that, it shouldn't stop us from building a domed colony on Mars.

Plus, when we do have the ability to build domes on Mars, I'm quite sure there would be a tracking/deflection system from NMO's, since the population would likely be a few hundred thousand at that point.

 

Edited January 15, 2016 by Spaceception

[fredinno]

1 hour ago, Spaceception said:

My Idea for a dome habitat on Mars:

Location: Crewe crater (Lets just assume it has water, which it probably does): Which is about 3 km across

The dome will encase the entire crater, and will look something like this (Only it'd be a geodesic dome):

Characteristics:

The dome: The domes glass will be made of aluminum glass (For strength) with a layer of liquid water underneath (For radiation protection), and will have grids of squares for maintenance robots that will repair anything that breaks on the dome.

The floor:

Water will cover 1/3 of the surface, and will be for fish farming.

Plant life will cover 1/4 of the surface

The martian city will cover the remaining 42% of the surface and will hold up to 5,000,000 colonists

The atmosphere:

Atmospheric pressure will be 85% Pressure at sea level, and will have 75% N 22% O2 2.6% Ar .4% CO2

Power:

Solar simply will not work on this scale, so Nuclear will be the only option, and it will be either a Thorium Breeder reactor or (more likely) A Fusion reactor.

Cost: Seeing as how most of the resources will already be on Mars, cost wouldn't really matter, so that brings us to:

Timescale: With constant construction, and lots of robotic helpers working day and night, it will likely take 8-15 years to build, and 2 years to finish (Liquid water, plants, breathable atmosphere, etc, etc).

So what do you guys think? Are any changes needed?

 

I also think it needs a smaller population to be viable on the long term- and you might want to reinforce it with carbon Nanotubes.

[DBowman]

@Spaceception maybe you can put the fish farm in the radiation shielding water in the dome. It's a two for one re resource usage and it would be cool to look up at the sky and see 'flocks' of fish.

[Spaceception]

23 minutes ago, fredinno said:

I also think it needs a smaller population to be viable on the long term- and you might want to reinforce it with carbon Nanotubes.

Why a smaller population for the long term? Carbon Nanotubes are good idea btw.

 

2 minutes ago, DBowman said:

@Spaceception maybe you can put the fish farm in the radiation shielding water in the dome. It's a two for one re resource usage and it would be cool to look up at the sky and see 'flocks' of fish.

, It's a dome, the fish will sink to the sides, so no fish above your head.
 

[AngelLestat]

14 hours ago, Chewy62 said:

A cavern on mars could be lined with "concrete" and layers of plastic for an airtight seal. radiation will be nearly nonexistent save for naturally occuring isotopes in the soil. 

Sure, live in caverns in mars is a great idea.. the problem is how you made the cave?  Those TBMs we use here are not light, they also require a lot of energy, even in the lower scale needed for mars.  Mars soil is soft, this is good for energy, but as you said it needs extra material to support itself. By yeah, I guess that is the best way for mars. 

Quote

Visibility will be very bad, so landing will need to be handled by robots.
-the bad part will be that a capsule with a huge battery and rotor is going to be heavy. 

Visibility at 53km is around 5 to 10km giving by the visible power flux. By the way, I don't see any robot landing airplanes when the visibility is zero XD.
http://forum.kerbalspaceprogram.com/index.php?/topic/129667-designing-a-venus-cloud-base/&do=findComment&comment=2358779
Big batteries mean more than 1 to 5 hours or charge.. It just need 10 to 20 min + autogyro (which it can be landed and directed without energy consumption), another method will be with a parafoil with a propeller behind. If something go wrong..  there are 2 options..  Descent until touch venus surface and wait until a "submarine" resque (capsules have a lot of insulation and resist enough pressure), or you may have a special ballon inflattion eject (just for the astronauts) where they can float at 53km. In their suits even if they leave the capsule at 40km altitude, they will be fine until they rise. 

14 hours ago, fredinno said:

Actually Mars is the closest to the Asteroid Belts... Also, the Asteroid belt is very dense in comparison to the rest of the solar system in terms of asteroid density, but it's also lost 99% of its mass. You'll be fine.

The asteroid belt is big, venus is closer. Venus has extra launch windows to a certain asteroid (I will said 1 year for venus and around 5 years for mars), if you need to send a spare to certain station, what do you do?
Venus has also the shortest flying time from the minimum energy trajectory..  but it paids a bit more of deltav...

11 hours ago, Albert VDS said:

How would you even be able to check every cm of this huge structure?

What is the rush?
I already show with math that a 5000 tons habitat using air as lifting gas will take 44 days to mix 1/4 of its air with a 3m diameter orifice in the envelope.
The envelope will be a sphere of 150m radius (just to make the math easier)

Quote

And then there is the mass issue, the colony has a mass limit per settlement depending on the carrying weight of the balloons.
You don't have that with a colony on a surface of a planet. On Mars you can have as you like and have more living space.

Yeah is an issue, but from the beginning all the things that you bring from earth needs to be the most lighter possible.. the same for mars xd.
And once you are enough advance in venus, each time you increase the surface envelope by a 30%, it means you can double your payload, so each time you have more lift by less cost. And one of the lifting gases is almost free in Venus.. Nitrogen.
Envelope radius and habitat mass:
150m--> 5000T
500m-->183000T

11 hours ago, DBowman said:

Thanks for the diagram - all that juicy mass not at the bottom of a gravity well. Apparently there are 1.7 M > 1 km in diameter, 'average separation' 10x Earth Moon distance. It's probably a power law thing on the sizes, I'm not sure how much of the 'very small stuff' got swept up by the larger ones. I feel like the collision probabilities are probably manageable, either via luck or mobility, I guess we'll find out more either from sims, tracking, or evidence on asteroids we 'investigate'. I feel like it a legitimate risk source that has to be characterized and accounted for, but at the moment I don't know enough to say it excludes asteroids as the most useful resources in the solar system.

Heh, why it matters if is in the gravity well or not?  You have plans to visit the outer planets with the asteroid colony?  Or visit other stars?  Because if you want to go the other direction (earth) you need to spent similar or more deltav than from venus.
About the size of the asteroids.. we can only detect asteroids of 1km or bigger.  This does not mean that there are not all the other sizes from a small stone to 900m floating around.. That for certain gives you higher chance of being hit than in orbit around the earth, where planets was cleaning the area by 4000 millones of years.

Quote

Re solar I think at 0.5 bar it's in the clouds so say 400 w/m2, If you din't account for the day/night factor then it looks pretty much like the mid to outer belt, but without the zero-g and no weather material & construction advantage.

I have it into account. 
http://forum.kerbalspaceprogram.com/index.php?/topic/129667-designing-a-venus-cloud-base/&do=findComment&comment=2357790
You may find the source of that info some post below. 

Quote

Raising the periapsis would be the challenge because while you have 'all the time in the world' to setup the encounter you have a limited time to kick the periapsis higher. This might well mean it's more effective to do the refining, and probably manufacture, at the asteroids so you can leave the dross behind and only deltaV the productive mass.

Yeah, you should act fast in after the first encounter. For small asteroids may be not so hard. Also your first asteroids you choose, will be those who contain the higher % of heavy elements you can find, so you don't lose time and money with the waste.. Is like if in the ten century here on earth, we would be bothering to remove 1km3 of land to find few diamons or gold, when in that time you find those in the surface. 

9 hours ago, magnemoe said:

Base looks nice, however I would prefer an more sectioned balloon system for redundancy, also the deck looks heavy, why not use an lattice structure. (yes it would increase polygon count a lot I understand)

Yeah, I dont know what details or theory development behind the design the mod creator had into account.  too bad that is not for KSP, it would be fun try that landing.. 

3 hours ago, Spaceception said:

The dome will encase the entire crater, and will look something like this (Only it'd be a geodesic dome):

Heh, I like it.  it has its flaws, but I guess for the long term step, mars advocates should think out of the box to compete with venus advantages.
This mean different ways to achieve long habitable areas without huge cost.
What I like of this idea is that the structure is self supported by the pressure difference. 
Someone knows an estimative chance to be hit it by a rock in mars at that area?
The inside atmosphere should be as low as possible, 0.3 bar will reduce a lot the forces on the dome.
Radioactive shielding would not work.. An atmosphere provide 1200g/cm2 meanwhile the spacestation provide 10g/cm2, and mars atmosphere 20g/cm2.
Not sure how crazy is magnetic shielding.. 
 

Edited January 15, 2016 by AngelLestat

[Spaceception]

12 minutes ago, AngelLestat said:

Heh, I like it.  it has its flaws, but I guess for the long term step, mars advocates should think out of the box to compete with venus advantages.
This mean different ways to achieve long habitable areas without huge cost.
What I like of this idea is that the structure is self supported by the pressure difference. 
Someone knows an estimative chance to be hit it by a rock in mars at that area? 
Radioactive shielding would not work.. An atmosphere provide 1200g/cm2 meanwhile the spacestation provide 10g/cm2, and mars atmosphere 20g/cm2.
Not sure how crazy is magnetic shielding.. 
 

Thanks.

On the radiation side of things.... There are these "Lumpy magnetic fields" on Mars, maybe we should stick our colony under one of those?

Edited January 15, 2016 by Spaceception

[DBowman]

Just now, AngelLestat said:

Heh, why it matters if is in the gravity well or not?  You have plans to visit the outer planets with the asteroid colony?  Or visit other stars?  Because if you want to go the other direction (earth) you need to spent similar or more deltav than from venus.

About the size of the asteroids.. we can only detect asteroids of 1km or bigger.  This does not mean that there are not all the other sizes from a small stone to 900m floating around.. That for certain gives you higher chance of being hit than in orbit around the earth, where planets was cleaning the area by 4000 millones of years.

I have it into account. 
http://forum.kerbalspaceprogram.com/index.php?/topic/129667-designing-a-venus-cloud-base/&do=findComment&comment=2357790
You may find the source of that info some post below. 

Yeah, you should act fast in after the first encounter. For small asteroids may be not so hard. Also your first asteroids you choose, will be those who contain the higher % of heavy elements you can find, so you don't lose time and money with the waste.. Is like if in the ten century here on earth, we would be bothering to remove 1km3 of land to find few diamons or gold, when in that time you find those in the surface. 

1. Materials sourced from planets pay a deltaV penalty to make them usable anywhere else, I'm imagining the asteroids as the 'industrial bread basket' for the solar system. I guess I should work out some numbers that include the effect for escaping the planet from low orbit and getting to different destinations (which is what I think you are talking about above), but just getting stuff 'up' costs like:
   1. Earth - 9.3 - 10 km/s
   2. Mars - 4.1 km/s
   3. Venus - infinity - well good luck getting stuff off the surface (I'm sure it's possible)
   4. Asteroids - 0 km/s
2. Yep I'm sure there are, or were lots of smaller ones, it's not clear to me that some / many have not been 'swept up' by the larger ones. I thought we'd got down to observations of ones at 10s of meters and estimates for counts down to 100m ( Wikipedia ). There is going to be a lot of empty space, but future surveys will give us some real numbers to work with. There is not much practical difference between 2 in 10^12 and 4 in 10^12, also Earth is a gravity 'magnet' so that would tend to increase the likely hood of being hit by something in it's vacinity compared to what you'd expect?
3. I saw your excellent post on potential power sources for Venus Cloud City and was about to correct myself. I particularly liked the Thermal Gradient one. The kites can be used to navigate the city also? It looks like you think there is a factor of 2 or 3 advantage to Venus in atmosphere PV generation, I kinda doubt it counteracts the material/structural penalty associated with building in the atmosphere.   
4. I guess we'd need some detail re Venus import requirements to see how likely it is to find a conveniently small asteroid with close to the right balance of elements, some balance between search costs and refine and separate in the belt. If what Venus needed happened to be what was easy to find a good match for then you have to decide if you manufacture from it in Venus orbit (++solar power) or in Venus cloud city. I imagine you'd probably end up with a substantial Venus orbital presence.

[Panel]

59 minutes ago, Spaceception said:

Thanks.

On the radiation side of things.... There are these "Lumpy magnetic fields" on Mars, maybe we should stick our colony under one of those?

These are interesting. What causes them, and how strong are they?

[Spaceception]

2 minutes ago, Panel said:

These are interesting. What causes them, and how strong are they?

I dunno, here's a couple of articles from the early 2000s though (When I guess they were discovered): http://www.colorado.edu/news/releases/2001/11/27/new-research-cu-reveals-mars-lumpy-magnetic-field

http://www.skyandtelescope.com/astronomy-news/marss-bumpy-magnetism/

 Although apparently from the second article, it's a few percent as strong as Earths magnetic field, so it could provide at least some radiation protection.

 

[fredinno]

8 hours ago, Spaceception said:

Why a smaller population for the long term? Carbon Nanotubes are good idea btw.

 

, It's a dome, the fish will sink to the sides, so no fish above your head.
 

Not enough food and air.

[Spaceception]

9 minutes ago, fredinno said:

Not enough food and air.

The plant life would recycle the air (Which should be adequate on that scale), and would mostly be food.

[fredinno]

1 hour ago, Spaceception said:

The plant life would recycle the air (Which should be adequate on that scale), and would mostly be food.

You also wanted fish in there, which would consume more food and air...

[Spaceception]

6 hours ago, fredinno said:

You also wanted fish in there, which would consume more food and air...

Fish would consume air? And the food that fish would need could be grown hydrophonicly

[steve_v]

4 minutes ago, Spaceception said:

Fish would consume air?

Fish would consume oxygen.

[SargeRho]

Yes, because fish consume oxygen that's dissolved in the water. Which comes from the air, or from algae and plants in the water.