Venus vs. Mars colonization

[K^2]

21 minutes ago, magnemoe said:

Ok an flying aircraft carrier, sounds plausible, in fact its very plausible compared to first launching it into space sending it to Venus and insert it into the atmosphere and operate it. 
It has been done experiments with flying aircraft carriers, all used docking instead of landing, however here the base will be very slow and the plane fast so you need an floating runway. 

As I say this idea is insane even in KSP, please try to do it on EVE in KSP, use any mod you like but use realistic buoyancy on balloons. 
negative if you need stuff like orion nuclear pulse engines to get it of the ground. 

For the same weight requirements as this project you could easy build an major base on mars able to do expeditions over all over the planet with airplanes or suborbital rockets. Base should be able to produce much of the food it needed and lots of materials too. 

Balloons supporting a Venusian colony would weigh almost nothing. To protect the same area from radiation exposure alone would require far more weight on Mars. Not to mention the fact that once you establish a greenhouse, you can start producing materials to expand the colony.

And all that's required is a very short runway, since arresting cables will do all the work in actually stopping the lander. In contrast, you're suggesting airplanes on Mars? Good luck building runways for these monsters.

I get the impression that you're picturing Martian colony like a camping trip. Put down the tent, and you're set! You have radiation. You have hurricane winds. You have inability to travel anywhere, because trying to fly there is insanity, and driving can be done at barely above pedestrian speeds. And all you get in return is piles, and piles of sand. Sand you'd probably be able to refine into something useful, if you can just keep the bloody solar farms from getting destroyed by constant sand-blasting.

[Albert VDS]

3 hours ago, AngelLestat said:

I imagine that for prove you are waiting to someone do it for real in venus.. but you not need any proof for mars? What kind of argument is that?

1- there are a lot of good light materials in market that block hydrogen by many years, graphene oxide is in development and will work better and be cheaper.  

2- not sure what is the issue with this..  you think that is not possible to track the position of a vehicle without gps?  Or that is not possible to have a propeller to move in the atmosphere.

3- if an airplane can hold the shuttle.. why not an airship that is a lot more stable and does not need constant speed to fly. 

We've been landing on Mars for a few decades now, we "only" need to scale it up for larger payloads. We've also been launching rockets for quite some time now, I think it's reasonable to say that it would be much easier to launch one from Mars.

1- Sure there are a lot of light materials, but those materials also need to survive the harsh environment of Venus' atmosphere. You also have to assume that it would fail at one point, so what should they do if it actually fails? The possibility of some sort of failure increases overtime, even more so in an increasing colony.
2- GPS doesn't work on Venus because there is no GPS network around Venus, are you suggesting creating one for a small colony in an other world? Any wind unpredictable, going from orbit(which is predictable) to some random place(where ever the wind blows the colony) cost a lot of dV. According to this wind speeds could reach 140 m/s or 504 km/h, it would require some beefy motors to even counteract those speeds and it would increase the mass of a blimp hab. Basically you are at the mercy of the weather and hope that you can get into the right position to even get close to the blimp hab.
3- I'm not saying that it's not possible to hold an orbital rocket, I'm saying how feasible is it. Do we even know what the bare minimum mass of a orbit capable rocket from the upper atmosphere of Venus is? Where is it going to launch from? It can't have pointed at the blimp hab and there's no way of having a launchpad without tons of water. The only thing I can think of is dropping it from the blimp hab and hope the engines light.

Or in other words: the blimp hab would need to be unbreakable or maintainable(which requires supply missions from Earth), able to counteract winds up to 504 km/h or hope the wind doesn't blow it off course and withstand a launch from it or just YOLO the rocket off of it and hope for the best.

[PB666]

On January 11, 2016 at 9:34 PM, K^2 said:

Terminator winds are strongest on planets with rare atmosphere, and much weaker on planets with thick atmosphere. There are certainly high winds at altitudes we are talking about, but they have relatively low shear. This is evidenced by the cloud observation data. You wouldn't be able to hold the colony anchored in one place, but it will drift in relative calm. Furthermore, relatively minor steering will be necessary to keep it circulating around constant latitude. Which is all you really care about.

Water vapor content in Venusian atmosphere is quite significant. More than enough to extract hydrogen for the support structures. And since, as I've pointed out, Venusian atmosphere contains no oxygen, or anything else for hydrogen gas to react with violently, hydrogen will be as safe as helium, so long as habitat modules and buoyancy modules are well separated.

 

With exception of flammability, airship have fantastic safety record on Earth. Additionally, we have a lot of experience with huge floating structures in sea, including their ability to withstand weather. It's not quite the same thing, but in terms of being able to resist stress due to variations in buoyancy, a lot of this knowledge would carry over.

 

That would be a good first step, yes. But the only reason we'd build one on Earth is to prepare for a mission to Venus, which I'm trying to convince you lot is a good idea. By no means do I suggest we go in half-cocked and just go directly for a build on Venus with no testing or preparation.

Unfortunately, Earth's weather would prevent us from building a true full-size implementation at low altitude, and we don't have enough air to support something so massive at high altitude. But we can certainly build and test individual modules, floating them above oceans or some other large, open areas. It might even be a good idea to run a few mock landings to make sure we can land people and cargo on it safely from orbit. I'm picturing lifting body entry capsule landing on short carrier-style deck with arresting cables. But that's just off the top of my head.

Sulferic acid is extremely hydroscopic

[Bill Phil]

On January 11, 2016 at 4:37 AM, Kaos said:

More energy (because of more light, because of proximity to the sun), faster communication home (proximity to earth). Then we have an atmosphere where we can extract resources uniformly from. And a gravity, so you have to build less or smaller (in case it turns out that mars gravity is to low to live healthy) artificial gravity stuff. Not to forget the better protection from radiation and micrometeorites by the atmosphere.

Nevertheless, asteroids are valid targets, too.

There are Trojan asteroids that get the same energy from the sun (give or take). And apollo asteroids cross Earth's orbit, as I recall.

These would have good communication to, especially the Trojans, at least people from there would be at a smaller range of distances.

The gravity already present is nice, but it's a double edged sword. It takes more energy to get to the colony.

I'd say planets and asteroids are pretty equal.

[Kaos]

2 minutes ago, Bill Phil said:

There are Trojan asteroids that get the same energy from the sun (give or take). And apollo asteroids cross Earth's orbit, as I recall.

These would have good communication to, especially the Trojans, at least people from there would be at a smaller range of distances.

The gravity already present is nice, but it's a double edged sword. It takes more energy to get to the colony.

I'd say planets and asteroids are pretty equal.

I mainly though about asteroids from the asteroid belt. You are right, this argument does not count for some of the closer asteroids. The other arguments still count.

[Bill Phil]

On January 10, 2016 at 2:28 PM, K^2 said:

Tell that to 3,000 people at WTC. Fact is, we already have countless people living in far more dangerous conditions. We have people living in flood areas, sides of volcanoes, tornado alleys, and poorly constructed buildings in seismologically active areas of the planet. Skyscrapers are safe in comparison, even when you consider that it's hard to escape from a 100th floor of a building if something's happening to it.

A cloud colony would be safer yet. Because the atmosphere lacks oxygen, meaning you don't have to worry about fires nearly as much. The structure doesn't have the single point of support, like a foundation, because individual sections have their own flotation support. And if section you're in does happen to start falling, you do actually just walk out. You walk out into an adjacent section. Not by climbing a hundred flights of stairs, but by stepping through a few doors.

All of the arguments you are making, are all of the same arguments people make about airplane flights. And it's still the safest mode of travel we have. Because "landism" is a fallacy. There is nothing inherently safe about being on land.

Except that with venus if you did fall, you'd die before hitting the ground, which you wouldn't do.

There is an inherent safety of land. It's relatively stationary and not dependent on machines to stay that way.

There is no inherent safety of air either. It's just better kept than other methods of travel.

[Panel]

What elements does the Mars surface have to offer? Could we materials from Mars that we couldn't from asteroids?

[Findthepin1]

Technically, since the rocky planets are made out of asteroids, there's nothing we can't get from an asteroid that we can find somewhere inside a planet.

[Bill Phil]

42 minutes ago, Findthepin1 said:

Technically, since the rocky planets are made out of asteroids, there's nothing we can't get from an asteroid that we can find somewhere inside a planet.

They're made of similar compounds, if not the same compounds, but for planets you only have access to a tiny portion of the total resources at a time. With roids you can move around them much easier. You have access to more material of the asteroid at a given time.

[YNM]

13 hours ago, Bill Phil said:

Except that with venus if you did fall, you'd die before hitting the ground, which you wouldn't do.

There is an inherent safety of land. It's relatively stationary and not dependent on machines to stay that way.

There is no inherent safety of air either. It's just better kept than other methods of travel.

Actually, you need both, not just one. Land without air is nothing (picture the Moon), so does air without land (unless... you're on gas giants ?).

One thing that people really needs to remember : Martian atmosphere is basically thinner than thin air. Liquid water (and most other liquid) will vaporize there in a short notice, which is also likely for water ice to sublime off once properly uncovered, when the temperature is high enough.

[AngelLestat]

On 12/1/2016 at 0:39 AM, fredinno said:

A Mars habitat is much more useful economically. Your options for economic activity are limited 70km away from a planetary surface- especially since a lot of people will go to see landforms.

Ok lets find out..  can you make a list of things you will need to make this mars habitat including travel and landing from the things you need?  just a rough estimation.  What you will need to make a partially sustainable habitat?
Then we (venus advocates) can make our estimates on a cloud habitat and compare.  I guess that is the only way to have a real idea what seems better. In fact if I see that there is a point where I can suggest an efficient approach to mars I will do. 

22 hours ago, magnemoe said:

Ok an flying aircraft carrier, sounds plausible, in fact its very plausible compared to first launching it into space sending it to Venus and insert it into the atmosphere and operate it. 

What you mean?  I did not understand the example.. 
About a runaway, is possible, but it does not match with the design that a venus hábitat should follow..  which is being aerodynamic and stable (like a spheroid, where its payload is in the bottom).

Why not a parafoil with an electric propeller?  With an alternative method or extra parafoil in case something happen.

15 hours ago, Bill Phil said:

Except that with venus if you did fall, you'd die before hitting the ground, which you wouldn't do.

There is an inherent safety of land. It's relatively stationary and not dependent on machines to stay that way.

There is no inherent safety of air either. It's just better kept than other methods of travel.

1-A capsule by design has very good thermal insulation, so even if your systems fail.. If you have at least 4m2 of parachute you will touch land very soft, then using all the energy to stay cool until a special submarine rescue you, the chances are not good,  but is a possibility than mars people does not have.. You can just use 1 propulsion to land on mars, and you dont cant miss the land level. 
Also if you walk on mars and you fall hitting your helmet with a rock.. you are death. 

2-You don't require of machines to stay floating in venus either. A ship floating in the sea is in danger because does not touch the sea floor?

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

Sorry, I mistake in this post on hydrogen vs breathing air as lifting gas:
http://forum.kerbalspaceprogram.com/index.php?/topic/129619-venus-vs-mars-colonization/&do=findComment&comment=2358035
I made the correction.

 

Edited January 13, 2016 by AngelLestat

[SargeRho]

2 minutes ago, AngelLestat said:

Ok lets find out..  can you make a list of things you will need to make this mars habitat including travel and landing from the things you need?  just a rough estimation.  What you will need to make a partially sustainable habitat?
Then we (venus advocates) can make our estimates on a cloud habitat and compare.  I guess that is the only way to have a real idea what seems better. In fact if I see that there is a point where I can suggest an efficient approach to mars I will do. 

 

I'm going to go off of 2 assumptions here.
1: We have some sort of super-heavy launch vehicle, such as the BFR.
2: Subsurface water ice is abundant, which appears to be the case.

First of all, we need a reliable power source. A thermoelectric nuclear reactor would do the trick, or one using sterling engines or brayton turbines, which would be less reliable though.

For a sustainable habitat, you need a source of nitrogen, water and oxygen first and foremost. Since water can be split to release oxygen, we have that part covered, and plants can convert CO2 into Oxygen, and the Atmosphere, as well as the soil, contain Nitrogen and nitrogen-rich minerals. Food will be mostly brought along by the colonists at first, until the greenhouses can provide all of their food.

Next we need some way of keeping the first generation of plants alive. We can use the subsurface water ice, combined with imported nutrients for that. I think aeroponics or hydroponics would be the best candidate at first, since soil is heavy, and you'd have to import that from Earth at first. 
https://s-media-cache-ak0.pinimg.com/564x/8c/0f/36/8c0f367e1ac0181ebd5fa1d265700272.jpg

Then we need a source of spare parts. Producing large mechanical parts shouldn't be much of an issue, since metals like iron, aluminium, titanium, nickel and manganese are very common on Mars. We'd have to develop a metalworks plant that can convert martian sand into useful metals. I don't know much about metallurgy though. Electronics would likely have to come from Earth for a while, as would smaller mechanical parts.

The initial habitats would need to be brought from Earth. A good solution would be inflatable habs that are then covered in Martian soil, either in the form of sand bags, or via 3d printing, as ESA proposed for  the Moon: http://lunarscience.nasa.gov/wp-content/uploads/2013/02/lunarbase3dprinting.jpg

Now you have a Mars habitat that can keep its inhabitants alive, without having to import everything from Earth.

Things that will have to be imported from Earth for a while, both on Mars and Venus, will be medical supplies, spare parts, and people. And of course space suits and vehicles.

Another thing that would be very useful are lightweight spacesuits, perhaps mechanical compression suits, that allow the inhabitants to move around with enough freedom to be able to do stuff outside.
Also a fuel plant, producing Liquid Methane and Liquid Oxygen rocket fuel, to refuel the landers to be sent back up, either right back to Earth, or acting as shuttles between some sort of space freighter and the surface.

Space Freighter that carries large amounts of cargo between Earth and Mars, and/or Earth and Venus, would be very useful for just about any long term endeavour in space I think.

 

[fredinno]

5 hours ago, Panel said:

What elements does the Mars surface have to offer? Could we materials from Mars that we couldn't from asteroids?

What elements does Venus atmosphere have to offer? Could we get materials from Venus that we couldn't get from asteroids, or even the Moon?

3 hours ago, Bill Phil said:

They're made of similar compounds, if not the same compounds, but for planets you only have access to a tiny portion of the total resources at a time. With roids you can move around them much easier. You have access to more material of the asteroid at a given time.

Still, Tharsis has a higher concentration of heavy elements, which also happen to be the more expensive ones..

1 hour ago, AngelLestat said:

Ok lets find out..  can you make a list of things you will need to make this mars habitat including travel and landing from the things you need?  just a rough estimation.  What you will need to make a partially sustainable habitat?
Then we (venus advocates) can make our estimates on a cloud habitat and compare.  I guess that is the only way to have a real idea what seems better. In fact if I see that there is a point where I can suggest an efficient approach to mars I will do. 

What you mean?  I did not understand the example.. 
About a runaway, is possible, but it does not match with the design that a venus hábitat should follow..  which is being aerodynamic and stable (like a spheroid, where its payload is in the bottom).

Why not a parafoil with an electric propeller?  With an alternative method or extra parafoil in case something happen.

1-A capsule by design has very good thermal insulation, so even if your systems fail.. If you have at least 4m2 of parachute you will touch land very soft, then using all the energy to stay cool until a special submarine rescue you, the chances are not good,  but is a possibility than mars people does not have.. You can just use 1 propulsion to land on mars, and you dont cant miss the land level. 
Also if you walk on mars and you fall hitting your helmet with a rock.. you are death. 

2-You don't require of machines to stay floating in venus either. A ship floating in the sea is in danger because does not touch the sea floor?

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

Sorry, I mistake in this post on hydrogen vs breathing air as lifting gas:
http://forum.kerbalspaceprogram.com/index.php?/topic/129619-venus-vs-mars-colonization/&do=findComment&comment=2358035
I made the correction.

 

You can jump off a ship and send a radio SOS call if things get really bad. Try that on Venus.

[Chewy62]

ITT: people try to convince you that a airship the size of an aircraft carrier is safer than a building. Especially comparing it to the WTC, which was hit by a freaking plane and still did not collapse immediately.

How will you solve the problem of sulfuric acid? I'm assuming things coming through the airlock will need to be washed down before they can come inside, and the exterior will need to be free of anything that is reactive with it.

The landing craft will need to have serious crossrange in case the platform drifts in the wind. Nevermind the fact you only get one try to land, otherwise you will fall to your death. Or a failure of the arresting cable.

[K^2]

1 hour ago, fredinno said:

You can jump off a ship and send a radio SOS call if things get really bad. Try that on Venus.

Try that on Mars. Or are you planning to never take the space suit off? That'll get old fast.

On a Venus base, the entire structure needs to fail before you are actually in trouble. If you have to evacuate a section, worst case scenario, you can even make a short dash outside. You'll need medical attention afterwards, but you'll live. On Mars, a crack in just one of the panels is enough to kill you, and you simply cannot survive outside for any meaningful amount of time. If you were in a section that lost pressure, and didn't make it to the exit before automatic doors shut, you are dead.

[magnemoe]

On 12.1.2016 at 7:33 AM, K^2 said:

Balloons supporting a Venusian colony would weigh almost nothing. To protect the same area from radiation exposure alone would require far more weight on Mars. Not to mention the fact that once you establish a greenhouse, you can start producing materials to expand the colony.

And all that's required is a very short runway, since arresting cables will do all the work in actually stopping the lander. In contrast, you're suggesting airplanes on Mars? Good luck building runways for these monsters.

I get the impression that you're picturing Martian colony like a camping trip. Put down the tent, and you're set! You have radiation. You have hurricane winds. You have inability to travel anywhere, because trying to fly there is insanity, and driving can be done at barely above pedestrian speeds. And all you get in return is piles, and piles of sand. Sand you'd probably be able to refine into something useful, if you can just keep the bloody solar farms from getting destroyed by constant sand-blasting.

No mars is far from an camping trip, environment is more like space than on earth. However we have operated in space for many decades, had space stations for many decades. 
Mars is simpler, you use dirt for radiation shielding if needed. You have solid ground to build on, this make it simple to add redundancy. You would probably use an reactor over solar power, you need heat anyway. 
Its easy to build larger structures as tents for settings were you are willing to skimp on radiation shielding like greenhouses and hangars. 

Finally boots on ground at mars make sense in doing science, an human is far more flexible than an robot and is also good at fixing stuff. 
Like Venus you will also do a lot of remote control who is easier without lightspeed delay. 

An Mars plane is unproven technology and far from sure is an manned plane is practical. Nasa has however thought about drone planes as realistic missions. 
Anything else is simply scaled up stuff from mars and space operations, has an lot of studies and can be started as soon as someone provides the cash. 
---
Both bases need an ground to orbital rocket. This is far easier to do on Mars, landing is also way easier as you only need an flat area not to far from the base. 
You just drive to the rocket for launch. 
On Venus you will need an earth sized rocket inside its own airship. 

You will prefer to refuel on base, on mars you will probably drive an huge truck under the launcher and move it to the refiling facility. Same can be done with an SSTO rocket who is larger. 
Supplies will be dropped and collected by truck the same way. You would run trucks on fuel cells as is done on real hydrogen cars today, you will also need oxygen so range will be lower. 

Now fueling up the rocket on Venus will require docking two airships for an decent time, longer if it serves as an escape system. 
Note that you will have to dock lots of stuff if base is to grow over time like ISS, an Mars base would do this and its no problems doing it. 
Doing an powered landing on top of an balloon does not sounds like an good idea, you have two fail modes, you miss and lose the crew or you crash and lose the balloon.
SSTO forget it with current technology. Note that I talk near future stuff here say 2030-60.

[K^2]

Most of science you'd be doing on Venus is atmospheric. That's done primarily with aircraft even on Earth, so boots on ground is kind of a moot point here.

Speaking of planes, yes, you can build a drone that will operate on Mars. The trouble is with making it practical for transportation. Low pressure means very high stall speeds. Which means there is absolutely zero way of landing or taking off from a runway. You need VTOL. Which you don't have air for, so you have to use rockets. Now, if you take a look at how much fuel is wasted on VTOL aircraft on Earth, and adjust for the fact that a rocket eats about 10x as much fuel for hover as something like Harrier jet engine, you should start seeing how it's not a good idea. You can definitely have a plane for emergencies. You should, in fact. Search and rescue, that sort of thing. But you can't use these routinely for transportation. You'll never mine enough fuel to keep them running.

Expanding a cloud city is actually easier than doing the same work on Mars. Workers can work outside on Venus wearing a light hazmat suit. Construction can be done with polymer pipes. No heavy machinery needed. No cranes, either, as every block is literally designed to support itself and can be easily moved around. All of the materials would be made from plant by-products. So you don't need mining, or mining equipment. Have we even discussed mining in near-vacuum? Because it's not easy.

Yes, we have a lot of experience of keeping a few people in a large tin can in space for a long time. We have some experience attaching modules together and doing minor repair work. We have nothing like the sort of experience we need to actually construct things from scratch in a space-like environment. And it's even worse on Mars. You don't have enough pressure to make oxygen mask a viable option, but you have enough pressure for dust storms. Fun!

Gas giants aside, Mars' surface is about as inhospitable an environment as we have in the Solar Systems. We can build a colony that will survive there, but making it self-sufficient is outside of our reach right now.

 

The only indisputable point is that it will be much easier to ascend from Mars. Venus ascent would require equivalent rocket to Earth ascent. Maybe even a tiny bit heftier. (If scale height of 15km holds, it can be as much as 500m/s of extra dV for ascent from a cloud city vs. ascent from Earth.) Mars, in contrast, is practically airless for the purpose of ascent, and we are looking at almost 3x less dV compared to Earth/Venus ascent. Which means that a mars ascent vehicle is certainly going to be an SSTO craft.

Other than the size of the rocket, however, there are no additional difficulties on Venus. It would be straight forward enough to have a dedicated module for launches, which can carry the rocket away from main colony prior to launch, not unlike what you'd do with a tracked vehicle on Earth. Alternatively, air launch is an option. Deploying a large aircraft from Venus is as easy as dropping it off underneath. Disposable winged stage would be a bit more expense, but it might be worth it for the ease of the launch.

All in all, all this is really saying to me that Mars is a much better place for a temporary outpost, supplied from Earth. So long as you stay marooned on the base, it's reasonably safe, and you can maintain the base with equipment from Earth. Then, if things go south, you just jump into an SSTO craft and wave the base goodbye as you ride to orbit. Venus, in contrast, makes much more sense as a permanent, nearly self-sufficient colony which, hopefully, can become entirely self-sufficient over time. Yes, it will be much more difficult to leave it, but the idea is that people wouldn't do that nearly as often. It wouldn't be a two year expedition trip, but more of a relocation for work. A place you'd go to for many years, perhaps even decades. And that's really what we want to build. A Jamestown of sorts.

 

P.S. Why do you keep saying "An Mars..."? I can't picture any way to pronounce "Mars" to start with a vowel sound.

[Rakaydos]

Out of curiosity, is it structurally possible  to build an orbital rocket entirely out of carbon-base materials? Carbon fiber tanks and RP1 fuel seem natural enough, but can you build a turbopump without metal?

[Kaos]

Carbon is ultra versatile. So I would guess it is possible (but for the fuel; RP1 is not only carbon, also you need an oxidizer, which might also not be carbon).

[K^2]

1 hour ago, Rakaydos said:

Out of curiosity, is it structurally possible  to build an orbital rocket entirely out of carbon-base materials? Carbon fiber tanks and RP1 fuel seem natural enough, but can you build a turbopump without metal?

Certainly. The only part I'm not sure about is the actual engine. Combustion chamber, nozzle, and the bell. Parts where temperatures are really high. Graphite works well for smaller rockets, but might not be a suitable material for larger ones. In particular, it might prove too brittle, and there is no good carbon-only way to add a matrix and retain thermal resistance. At least, none that I know of. So engines for ascent rockets might need to be imported.

[Kaos]

24 minutes ago, K^2 said:

Certainly. The only part I'm not sure about is the actual engine. Combustion chamber, nozzle, and the bell. Parts where temperatures are really high. Graphite works well for smaller rockets, but might not be a suitable material for larger ones. In particular, it might prove too brittle, and there is no good carbon-only way to add a matrix and retain thermal resistance. At least, none that I know of. So engines for ascent rockets might need to be imported.

I think diamond might go. We do not know how to make artificial diamonds of that size, but in principle it should be possible.

[K^2]

Diamond is even more brittle, and doesn't like heat. It'd be worse than graphite for engine components.

[fredinno]

On 1/12/2016 at 10:33 PM, K^2 said:

Balloons supporting a Venusian colony would weigh almost nothing. To protect the same area from radiation exposure alone would require far more weight on Mars. Not to mention the fact that once you establish a greenhouse, you can start producing materials to expand the colony.

And all that's required is a very short runway, since arresting cables will do all the work in actually stopping the lander. In contrast, you're suggesting airplanes on Mars? Good luck building runways for these monsters.

I get the impression that you're picturing Martian colony like a camping trip. Put down the tent, and you're set! You have radiation. You have hurricane winds. You have inability to travel anywhere, because trying to fly there is insanity, and driving can be done at barely above pedestrian speeds. And all you get in return is piles, and piles of sand. Sand you'd probably be able to refine into something useful, if you can just keep the bloody solar farms from getting destroyed by constant sand-blasting.

Mars Dust Storms are actually very weak in force, which is the reason Opportunity has ended up operating for so long.

And I think you are heavily underestimating the mass of an airship balloon. Even parachutes are surprisingly massive.

[AngelLestat]

On 13/1/2016 at 2:00 AM, SargeRho said:

I'm going to go off of 2 assumptions here.
1: We have some sort of super-heavy launch vehicle, such as the BFR.
2: Subsurface water ice is abundant, which appears to be the case.
First of all, we need a reliable power source. A thermoelectric nuclear reactor would do the trick, or one using sterling engines or brayton turbines, which would be less reliable though.
For a sustainable habitat, you need a source of nitrogen, water and oxygen first and foremost. Since water can be split to release oxygen, we have that part covered, and plants can convert CO2 into Oxygen, and the Atmosphere, as well as the soil, contain Nitrogen and nitrogen-rich minerals. Food will be mostly brought along by the colonists at first, until the greenhouses can provide all of their food.
Next we need some way of keeping the first generation of plants alive. We can use the subsurface water ice, combined with imported nutrients for that. I think aeroponics or hydroponics would be the best candidate at first, since soil is heavy, and you'd have to import that from Earth at first. 
https://s-media-cache-ak0.pinimg.com/564x/8c/0f/36/8c0f367e1ac0181ebd5fa1d265700272.jpg

Then we need a source of spare parts. Producing large mechanical parts shouldn't be much of an issue, since metals like iron, aluminium, titanium, nickel and manganese are very common on Mars. We'd have to develop a metalworks plant that can convert martian sand into useful metals. I don't know much about metallurgy though. Electronics would likely have to come from Earth for a while, as would smaller mechanical parts.
The initial habitats would need to be brought from Earth. A good solution would be inflatable habs that are then covered in Martian soil, either in the form of sand bags, or via 3d printing, as ESA proposed for  the Moon: http://lunarscience.nasa.gov/wp-content/uploads/2013/02/lunarbase3dprinting.jpg

Now you have a Mars habitat that can keep its inhabitants alive, without having to import everything from Earth.

Things that will have to be imported from Earth for a while, both on Mars and Venus, will be medical supplies, spare parts, and people. And of course space suits and vehicles.
Another thing that would be very useful are lightweight spacesuits, perhaps mechanical compression suits, that allow the inhabitants to move around with enough freedom to be able to do stuff outside.
Also a fuel plant, producing Liquid Methane and Liquid Oxygen rocket fuel, to refuel the landers to be sent back up, either right back to Earth, or acting as shuttles between some sort of space freighter and the surface.
Space Freighter that carries large amounts of cargo between Earth and Mars, and/or Earth and Venus, would be very useful for just about any long term endeavour in space I think.

Hi Sargerho, I dont have time for a full review.. also I will like you get some help from other mars advocates.. We (in the other thread) are trying to make a similar plan, we still need more time.  It will be fun to see what group have the best plan.
One thing: take into account that nuclear power or fussion or similar stuff, they all require cooling to measure its efficiency.   Here on earth we use huge cooling towers evaporating water that is lost and we have an atmosphere to help in the heat transfer..  In mars you can not waste water, is almost as difficult like get ride of heat in space, maybe worst if your radiators transfer heat to the soil or between them (depending the angle).
Any radioactive pollution will be dangerous than earth, because the atmosphere is 205 times less massive than earth (this means 205 times less radioactive diluted).

THe other ideas looks nice.

22 hours ago, Chewy62 said:

ITT: people try to convince you that a airship the size of an aircraft carrier is safer than a building. Especially comparing it to the WTC, which was hit by a freaking plane and still did not collapse immediately.

How will you solve the problem of sulfuric acid? I'm assuming things coming through the airlock will need to be washed down before they can come inside, and the exterior will need to be free of anything that is reactive with it.

The landing craft will need to have serious crossrange in case the platform drifts in the wind. Nevermind the fact you only get one try to land, otherwise you will fall to your death. Or a failure of the arresting cable.

What is ITT and WTC?  
The amount of acid in the air is almost none.. micro doplets that are not enough to harm you (in short exposures) because they just can react with the same amount of skin (also micro).
You get rid of the suit, you hang it on the rack and you go dinner, it will evaporate. In mars you really need special procedure to get ride of the dust which might do a lot of harm.

21 hours ago, magnemoe said:

On Venus you will need an earth sized rocket inside its own airship. 

Heh, why you need to launch your rocket from inside the city or airship? 
In that case in mars you will launch the rocket from the top of the habitats? XD
If you sent people only, this is how big is your rocket:

 

Edited January 14, 2016 by AngelLestat

[RuBisCO]

This is silly, a cloud city may look romantic, but it has huge problems compared to a mars colony.

A Mars colony has access to the surface with existence technology, we have yet to build anything that could operate on Venus for time periods longer then a few hours! How are we going to mine the surface for resources??? A Venus colony would be limited to only what is in the atmosphere, no metals, no heavy elements, doomed.

Personally I would say a Asteroid colony is the better then Mars, or Venus. The delta-v to get to an asteroid can be lower then Mars or Venus, a C type Asteroid has all the elements, water, nitrates, you name it, continuous solar power, no night cycles, no clouds, orbital cities could be built with centrifugal earth simulating gravity and meter thick walls made out of asteroid mined slag for shielding.