Venusian Atmospheric Density

[hypervelocity]

Hey all - hope everyone's having a great day!

I am running into a bit of a pickle here trying to find a venusian atmospheric chart and maybe someone here can be of help! I am trying to find a chart/table that displays atmospheric density by height. I am trying to send a balloon to Venus' upper atmosphere using KSP + RSS + RO and I would need this data to determine the volume and mass of my balloon.

I am only finding the value at surface level, which is 67kg/m3.

Thanks in advance!

Edited July 2, 2018 by hypervelocity
i suck at englando

[kerbiloid]

page 8, 14, 40
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730008097.pdf

Something is here, from 09:37, but resolution is poor.
https://slideplayer.com/slide/7257105/

[hypervelocity]

exactly what I needed, very much appreciated!

[K^2]

And with that paradise right in our backyard, we are looking at Mars for colonization for some reason.

[mikegarrison]

10 minutes ago, K^2 said:

And with that paradise right in our backyard, we are looking at Mars for colonization for some reason.

Hey, nothing wrong with 100 atm of pressure at 750 K -- if you're an autoclave.

[FireKerb]

Sulphuric Acid clouds? Eh, just coat your landing pod in soap.

[TheDestroyer111]

11 hours ago, mikegarrison said:

Hey, nothing wrong with 100 atm of pressure at 750 K -- if you're an autoclave.

Hey, nothing wrong with 1 atm of pressure at 320 K -- if you're an balloon fanboy.

[NSEP]

16 hours ago, K^2 said:

And with that paradise right in our backyard, we are looking at Mars for colonization for some reason.

At least you can easily extract a variety of resources on Mars, rather than taking a dive into almost litterly hell to collect a little bit of Iron or Aluminium for stuff. 

[magnemoe]

4 hours ago, TheDestroyer111 said:

Hey, nothing wrong with 1 atm of pressure at 320 K -- if you're an balloon fanboy.

Balloons are good for one thing, looking down on the ground below, communicating with it is an second but much the same. 
An mars or moon base has the benefit of being on an body with resources  who has high scientific interest. Mars win in both but is +20x times father away. 
An manned mission to Moon and Mars has plenty of benefit as in having astronauts walking around lifting up rocks and looking under or using drills and repairing stuff.  
Downside is that an manned mission is magnitudes more expensive than probes. 

An Venus colony has no benefit here, you could control the landers just as well from orbit. 

Building an space station in leo or L4/5 would be way cheaper and safer, also way more useful than an balloon base on Venus. 

[K^2]

9 hours ago, TheDestroyer111 said:

Hey, nothing wrong with 1 atm of pressure at 320 K -- if you're an balloon fanboy.

Or slightly less than 1atm, with slightly elevated oxygen fraction, at perfect 20^oC.

5 hours ago, NSEP said:

At least you can easily extract a variety of resources on Mars, rather than taking a dive into almost litterly hell to collect a little bit of Iron or Aluminium for stuff. 

Which you need for what, exactly? Most modern construction is hydrocarbons. A thick atmosphere rich in carbon dioxide, nitrogen, sulfur, and water vapor is the absolutely ideal manufacturing environment. The quantities of heavy metals and semiconductors we actually need are cheaper to import from asteroid belt. Mining on Mars is just stupid-hard, even compared to mining asteroids. Mars has the worst possible amount of atmosphere and gravity for any industrial operations. Things are still heavy, so you can't just float cargo around, but not comfortable for humans. You still need a pressurized vessel, but you get dust everywhere. It's hard to imagine a worse environment for a self-sustained colony.

4 hours ago, magnemoe said:

Balloons are good for one thing, looking down on the ground below, communicating with it is an second but much the same. 
An mars or moon base has the benefit of being on an body with resources  who has high scientific interest. Mars win in both but is +20x times father away. 
An manned mission to Moon and Mars has plenty of benefit as in having astronauts walking around lifting up rocks and looking under or using drills and repairing stuff.  
Downside is that an manned mission is magnitudes more expensive than probes. 

An Venus colony has no benefit here, you could control the landers just as well from orbit. 

Building an space station in leo or L4/5 would be way cheaper and safer, also way more useful than an balloon base on Venus. 

There is almost no research benefit to having boots on the ground, and what little there is rapidly evaporating. More importantly, there is no need to send hundreds of people to a research base. We're doing perfectly fine with 6 in LEO.

If your objective isn't to establish multiple self-sustaining colonies throughout the system, then you are on track for extinction. Mars is a dead end. It's a very bad place for a colony. Yet, for some stupid reason, we're spinning up infrastructure to colonize it. Martian colony is going to require constant upkeep for foreseeable future, and that completely defeats the purpose of having one. Venusian cloud colony can be self sustaining within a couple of decades, being able to expand, build daughter colonies, and at very least refuel, if not build from scratch, ships capable of reaching orbit, all using local resources. On Mars, fuel production alone, capable of supporting more than few launches per year, is going to be problematic, becoming one of the limiting factors on colony size.

And yeah, a free-orbiting space-station is easier than colony on either planet. But it's not going to be self-sufficient until we have permanent asteroid mining infrastructure. That could be a century out. If we want to have a backup home for our species, Venus gets us there with least amount of effort and in shortest time. Diverting resources towards anything else is silly.

[kerbiloid]

Spoiler

A Venusian cloud blimp colony with crewed yo-yo surface shuttle.

P.S.
In "Rose and Worm" sci-fi they have a fleet of floating islands made of superlight foam, with inner pressurized rooms, and name them laputa's (as appellative noun).

Edited July 4, 2018 by kerbiloid

[kerbiloid]

8 hours ago, K^2 said:

f your objective isn't to establish multiple self-sustaining colonies throughout the system, then you are on track for extinction.

Historically, wise people don't build 10 houses across the forest. They build 1, and hide 100 stashes with supplies to survive and restore the main if something bad happens.
Especially when there is exactly one place to really live in.
This works on Earth, why shouldn't outside?

8 hours ago, K^2 said:

Venusian cloud colony can be self sustaining within a couple of decades, being able to expand, build daughter colonies, and at very least refuel, if not build from scratch, ships capable of reaching orbit, all using local resources.

According to the pdf, page 19, there is ~10^-4..10^-1 % of water in Venusian atmosphere. (By volume, but by mass is more or less to, lazy to calculate).
Hydrogen is 1/9 of water by mass.
So, to get 1 kg of hydrogen on Venus you have to process hundreds tonnes of air.
On Mars you have to electrolize 9 kg of ice.

Even nothing to compare. The only thing you have on Venus is CO2. And some nitrogen.
Mars has water ready to use.

Mars has metal oxides and rocky Phobos/Deimos with low gravity.
Venus has all rocks on the bottom of a hell, and no low-gravity satellites.

Venusian orbital speed is twice greater, so it's a problem to deliver something there, and it's absolutely nothing to deliver from there.

And while you can just drop the Martian base on the surface, in Venusian atomsphere you have to make kilometers-sized huge ballons or clouds of foam (by a still unknown technology) to keep the same base like on Mars.

So, nothing to build on Venus.

P.S.
2 Moderators:  Maybe move the Venus colonization posts into the Colonization thread?

Edited July 4, 2018 by kerbiloid

[magnemoe]

7 hours ago, K^2 said:

Or slightly less than 1atm, with slightly elevated oxygen fraction, at perfect 20^oC.

Which you need for what, exactly? Most modern construction is hydrocarbons. A thick atmosphere rich in carbon dioxide, nitrogen, sulfur, and water vapor is the absolutely ideal manufacturing environment. The quantities of heavy metals and semiconductors we actually need are cheaper to import from asteroid belt. Mining on Mars is just stupid-hard, even compared to mining asteroids. Mars has the worst possible amount of atmosphere and gravity for any industrial operations. Things are still heavy, so you can't just float cargo around, but not comfortable for humans. You still need a pressurized vessel, but you get dust everywhere. It's hard to imagine a worse environment for a self-sustained colony.

There is almost no research benefit to having boots on the ground, and what little there is rapidly evaporating. More importantly, there is no need to send hundreds of people to a research base. We're doing perfectly fine with 6 in LEO.

If your objective isn't to establish multiple self-sustaining colonies throughout the system, then you are on track for extinction. Mars is a dead end. It's a very bad place for a colony. Yet, for some stupid reason, we're spinning up infrastructure to colonize it. Martian colony is going to require constant upkeep for foreseeable future, and that completely defeats the purpose of having one. Venusian cloud colony can be self sustaining within a couple of decades, being able to expand, build daughter colonies, and at very least refuel, if not build from scratch, ships capable of reaching orbit, all using local resources. On Mars, fuel production alone, capable of supporting more than few launches per year, is going to be problematic, becoming one of the limiting factors on colony size.

And yeah, a free-orbiting space-station is easier than colony on either planet. But it's not going to be self-sufficient until we have permanent asteroid mining infrastructure. That could be a century out. If we want to have a backup home for our species, Venus gets us there with least amount of effort and in shortest time. Diverting resources towards anything else is silly.

Boots on the ground is effective, however robots are more cost effective but slow. And ISS is to small, a 6 man crew uses to much time running the thing again an cost issue. 

I think near term as in 50 years, and you will not get an self sufficient colony in that time, yes it grows its own food but it can not create space suits and other complex items you need from scratch. items made with lots of parts with long supply chains with their own industries. 
That you can do is create trivling outposts who will grow, anything else risk being slashed in some budget cut. 

Now the most useful location is orbit and the L points, its an way-station between launch and deep space, tourism is obvious also useful for repairing GEO assets and build structures to large to launch. Also 0g manufacturing and processing raw materials from asteroids. 
Moon less useful, tourism, science some resources. 

Mars, primary science. Probably the easiest location to build on, lots of resources on site, downside is that this is not economical to export. 

Asteroids, lots of resources but not sure how much humans will be involved and even so it will not be large permanent settlements in medium term. 
However asteroids has the benefit of being both economical and so far from earth you need an decent degree of self sufficiency so that is that I would push for as in colonizing the asteroids. 
Building is around as hard as building in orbit, except farther from earth but lots of raw materials. 

Venus is way harder to build on, remember you have to build balloons you have to launch orbital rockets from and retrieve them. 
And as you say you need resources from asteroids anyway so in an self sufficiency perceptive if they fails you fail.

[K^2]

53 minutes ago, kerbiloid said:

Historically, wise people don't build 10 houses across the forest. They build 1, and hide 100 stashes with supplies to survive and restore the main if something bad happens.
Especially when there is exactly one place to really live in.
This works on Earth, why shouldn't outside?

Ever heard of keeping all eggs in one basket? This planet gets hit by large rocks quite frequently. If one comes by large enough to wipe us out, we can do absolutely nothing about it. We have to have at least one off-world self-sufficient colony. Simply having supplies out there isn't going to cut it, when whatever few survivors make it there, and can't continue to sustain themselves for centuries without supplies from Earth.

53 minutes ago, kerbiloid said:

According to the pdf, page 19, there is ~10^-4..10^-1 % of water in Venusian atmosphere. (By volume, but by mass is more or less to, lazy to calculate).
Hydrogen is 1/9 of water by mass.
So, to get 1 kg of hydrogen on Venus you have to process hundreds tonnes of air.
On Mars you have to electrolize 9 kg of ice.

And how do you propose getting that ice? First, it's not abundant everywhere. In most places, there is just a bit of ice mixed in with dirt.

So while you are looking for a place that has sufficient ice, setting up drills, equipment to melt and filter the ice, and all of it while traversing rugged terrain in an environment where getting a cut on your suit means death, I extend the hose, and start condensing water from air. While you are figuring out how to filter extremely fine dust from water without clogging the filter, I'm already drinking it. While you're figuring out how to fix damage due to coarser sand, I'm drinking fresh water. And when you run out of ice wherever you set up drilling and need to relocate, I'm drinking fresh water.

There are four things you need to survive several days. Heat, pressurized environment, breathable air, and water. I get the first two for free. You have to generate heat and maintain pressure. If you get a leak or an electric outage, you're done. If I have an atmo leak, I fix it with duct tape, because there is no pressure difference. And if I get power outage, I sit in the dark. And then getting water is effort on Mars, vs just setting up a fan and a condenser on Venus. Doesn't matter how dry the air is, because I can pump a lot of it through a condenser with very little effort. Oh, and habitable altitudes are at cloud layers, so while it's still pretty dry, it's significantly higher moisture content than average.

53 minutes ago, kerbiloid said:

Mars has metal oxides and rocky Phobos/Deimos with low gravity.
Venus has all rocks on the bottom of a hell, and no low-gravity satellites.

On Mars, these are also your only construction options. And mining on Mars is going to be a lot harder than mining on the Moon. Lunar dust is just as bad for machinery as Martian, but on the Moon it has decency to drop instantly back to the surface. On Mars, once you start drilling, that stuff will be everywhere. If you think keeping machinery operating in a desert is hard, you haven't tried it on Mars.

On Venus, you can go 100% organic and not bother with any significant quantities of minerals.

53 minutes ago, kerbiloid said:

Venusian orbital speed is twice greater, so it's a problem to deliver something there, and it's absolutely nothing to deliver from there.

Venus has thick atmosphere. Getting stuff to Venus is super easy. Entry speeds for cargo in-bound from Earth will be slightly higher than these of Apollo missions coming back from the Moon. Nothing a heat shield can't handle.

Landing on Mars, though? The atmosphere is too thin to properly slow you down, although still generates huge amounts of heat, and then parachutes are completely useless on the final leg. Yeah, you have less speed to kill than on Venus, but you're killing majority of it with rockets. And you can't exactly land a new module far from the base, because then you can't move it. But if rockets fail, you just bombed your own base. On Venus, any additional cargo can arrive miles away from habitats, and then be floated to the main base.

The main theme of all of this is that on Venus you have backups and redundancy built into the environment. On Mars, there is zero margin for error. If anything goes wrong, you can't fix it. If you there is a sand storm and solar panels are buried you are without power. If there is a hole in a habitat, that habitat is dead. If there is a problem with your module, and you have to dash outside, you better have a space-suit. On Venus, it won't be pleasant, but you can get out and fix something. You'll need a chemical shower, but you won't be dead. On Mars, radiation is a problem. You'll need shielding for habitats, and you'll need shielding for growing food, any of this fails, and you're done. If I need a new place to grow food on Venus, I can put some air into a plastic bag, and that makes an acceptable greenhouse. And this is across the board. Living on Mars is like skydiving without a spare parachute. You can come up with as many improvements to safety as you want, it only has to fail once. Not having a backup is stupid.

 

All arguments for Mars come down to "It has dirt". And it's toxic dirt, which won't support plant life, with fine, destructive dust, and almost no useful minerals unless you go through tons of it. It's another hazard of the Red Planet. Not a boon by a long shot. And once you give up on the idea of needing dirt under your feet - we all seem to be pretty much in agreement that free-floating space-station is quite acceptable - then Venus wins by default. Absolutely everything else is better there. Pressure, temperature, gravity, resources, solar power, radiation protection, and general lack of hazards.

 

Quote

And as you say you need resources from asteroids anyway so in an self sufficiency perceptive if they fails you fail.

The colony will survive if these shipments stop. Everything crucial to survival is present in atmosphere. Everything else is "nice to have".

Building a colony that won't die horrible deaths once shipments from Earth end on Venus is way, way easier than anywhere else in Sol system. We can have something self-sufficient there in decades. We cannot anywhere else.

Edited July 4, 2018 by K^2

[ARS]

I support the venus colony. The thing is, mars has too little resources needed for self sufficient colony, requiring too much resupplying and upkeep to keep it alive. Venus, although the surface is hell, the habitable area lies above the cloud layer and contains most if not all resources needed to at least create a colony with better capability than mars.

There is a layer in cytherean atmosphere where both temperature and pressure are Earthlike, located some 60 kilometers above the surface. The only non-Earthlike thing in this habitability zone is atmospheric chemistry, which is mostly CO2 with some sulfuric acid; but it also means that normal Earth air will work in this atmosphere like a lifting gas, easily supporting a Cloud City. Aside of the Moon, Venus is also the best place of the Solar System to see our planet. From there, Earth appears as a dazzling blue star that with a telescope would give a lot of fun as weather patterns change and continents/oceans move below because of its rotation. The Moon would appear almost as bright as we see Jupiter, and while looking much more dull than Earth it would contribute with still more fun for astronomers as the former orbits the latter and both bodies approached, moved away, and in some cases overlapped, unlike in mars, where the reliever of "I missed earth" feeling is only remedied by "a mote of dust, suspended in a sunbeam". As it's gravity is similar with earth, it's much easier to establish manufacturing facility without having to compensate for lower gravity. Also, the temperature and atmospheric pressure on the upper cloud layer is sufficient for a leaking spacesuit to be patched up with duct tape, as @K^2 said, while on mars, a leaking spacesuit is fatal. The transfer window and the time for earth-venus journey is also faster, allowing more frequent flight.

I don't see any point in colonizing mars. The idea of mars being habitable came from mistranslation of mars observation report. In the late 19th century, astronomer Giovanni Schiapparelli observed what appeared to be water channels on Mars. When his writings were translated into English, the Italian word canali was misleadingly translated as canals. For decades afterwards, it was widely believed that these had been built by intelligent aliens. And thus, after space race, 2 superpowers start throwing probes on the planet in hope of finding life. The planet was shown to be lifeless, a weak gravity and thin atmosphere also means that dust storms goes crazy on Mars. Every so often, a gigantic dust storm will cover the entire planet in a thick cloud of particles. The most damaging is that Mars has a core that's dead, with no tectonic activity at all, so there's no magnetic field to keep the solar wind from keeping the planet more or less sterile. Although science holds out hope that they will one day discover evidence that life once existed on Mars, there's very little hope they will find life living there now. Worse than that, the Martian soil is now known to be extremely rich in hexavalent chromium (known for short as HexChrome), one of the most potent carcinogens known to man. Today, the moons Europa and Enceladus are considered more likely to currently harbor life, both having verified subterranean liquid water and the protection of their respective home planets' magnetic fields. (Europa's surface ice is also a protective barrier from Jupiter's latent radiation.) While in 2015 it was finally verified that there is indeed liquid water on the surface of Mars, the lack of a magnetic field and toxic soil would still be severe obstacles to life. The concept of Martians quickly became discredited. More recent observations suggest that Mars may have supported life in the distant past, and some people still cling to hope that life may reside underground, no matter how unlikely it is. However, the red planet has had such a hold on human imagination for so long that it is not going to be lost as a setting any time soon.

[magnemoe]

10 minutes ago, K^2 said:

Venus has thick atmosphere. Getting stuff to Venus is super easy. Entry speeds for cargo in-bound from Earth will be slightly higher than these of Apollo missions coming back from the Moon. Nothing a heat shield can't handle.

Landing on Mars, though? The atmosphere is too thin to properly slow you down, although still generates huge amounts of heat, and then parachutes are completely useless on the final leg. Yeah, you have less speed to kill than on Venus, but you're killing majority of it with rockets. And you can't exactly land a new module far from the base, because then you can't move it. But if rockets fail, you just bombed your own base. On Venus, any additional cargo can arrive miles away from habitats, and then be floated to the main base.

The main theme of all of this is that on Venus you have backups and redundancy built into the environment. On Mars, there is zero margin for error. If anything goes wrong, you can't fix it. If you there is a sand storm and solar panels are buried you are without power. If there is a hole in a habitat, that habitat is dead. If there is a problem with your module, and you have to dash outside, you better have a space-suit. On Venus, it won't be pleasant, but you can get out and fix something. You'll need a chemical shower, but you won't be dead. On Mars, radiation is a problem. You'll need shielding for habitats, and you'll need shielding for growing food, any of this fails, and you're done. If I need a new place to grow food on Venus, I can put some air into a plastic bag, and that makes an acceptable greenhouse. And this is across the board. Living on Mars is like skydiving without a spare parachute. You can come up with as many improvements to safety as you want, it only has to fail once. Not having a backup is stupid.

All arguments for Mars come down to "It has dirt". And it's toxic dirt, which won't support plant life, with fine, destructive dust, and almost no useful minerals unless you go through tons of it. It's another hazard of the Red Planet. Not a boon by a long shot. And once you give up on the idea of needing dirt under your feet - we all seem to be pretty much in agreement that free-floating space-station is quite acceptable - then Venus wins by default. Absolutely everything else is better there. Pressure, temperature, gravity, resources, solar power, radiation protection, and general lack of hazards.

BFR demo showed one way to land on Mars and Mars has one benefit if your launch or landing fails you loose an rocket and an pad and missing the pad by 100 meter is not an automatic mission fail. 

On Venus you need an two stage launcher to get off so this require first stage return to pad, you also need to land upper stages arriving with more stuff and personell. 
You need the facilities to maintain and repair the rockets, rocket would at bar minimum has to be of the size of an falcon 9. 
You will need something close to an aircraft carrier to manage this. So yes you need an flying aircraft carrier just to get up and down, building this will be somewhat challenging. 
Any pad explosion or fail just after takeoff and you loose you flying aircraft carrier or your base if one unit, if not one unit or base is so large it manage to survive an rocket come crashing down and blowing up you lost your launch capability and can not get off anymore. Unless your base is so gigantic it has multiple launch facilities. or you have multiple flying aircraft carriers. 

On Mars or Moon you can use SSTO, you have multiple pads an good distance from base, fuel and launch facility will be armored with plenty of dirt.  
Armoring an balloon is pretty hard. 
In space you simply dock. 

In short setting up even an small base in Venus atmosphere require an flying aircraft carrier, that is the easy part
Recommend building one on earth first for testing. 

[ARS]

3 minutes ago, magnemoe said:

setting up even an small base in Venus atmosphere require an flying aircraft carrier, that is the easy part 
Recommend building one on earth first for testing. 

Cytherean atmosphere is much thicker than earth, you can't test something on Earth atmosphere and expect it to work on Cytherean atmosphere. On the other side, that thick atmosphere (being mostly CO2) allows normal air to be used as lifting gas, meaning balloon is much more effective there than on earth. You don't need an aircraft carrier, a balloon is enough to maintain a colony and infrastructure. As a bonus, being above the cloud layer, launching a rocket experience less drag in-flight and much easier to reach orbit, allowing a smaller rocket to lift same amount of mass compared with surface launch

[kerbiloid]

1 hour ago, K^2 said:

This planet gets hit by large rocks quite frequently. If one comes by large enough to wipe us out, we can do absolutely nothing about it.

It's much easier to reroute a large rock once per millenia than found a self-sustained colony on another planet.

1 hour ago, K^2 said:

We have to have at least one off-world self-sufficient colony. 

We have to have at least one off-world research & industrial base  with enough supplies to restore civilization on the devastated Earth.
(And a lot of hidden safe stashes with supplies just in case. They don't need people onboard.)
In any case unlikely you can evacuate billions, so that doesn't matter how capable is that base.

1 hour ago, K^2 said:

Simply having supplies out there isn't going to cut it, when whatever few survivors make it there, and can't continue to sustain themselves for centuries without supplies from Earth.

If you build ten houses in a forest, then ten houses will burn in case of fire.
And nine of them will be unused all other time.

That's why it's better to build one good house, and clean the space around it.
And hide 100 packs of supplies here and there.

1 hour ago, K^2 said:

And how do you propose getting that ice?

With this.

Spoiler

A rather strange question.

1 hour ago, K^2 said:

First, it's not abundant everywhere. In most places, there is just a bit of ice mixed in with dirt.

On Venus you don't have even this.

1 hour ago, K^2 said:

I extend the hose, and start condensing water from air.

~100 t (not m³) of "air" per several kg of water?
This hose would be thick.

Btw, how will you cool your condenser?
On Mars there is ice.

1 hour ago, K^2 said:

While you are figuring out how to filter extremely fine dust from water without clogging the filter, I'm already drinking it.

With sulfic acid. 

1 hour ago, K^2 said:

If you get a leak or an electric outage, you're done. If I have an atmo leak, I fix it with duct tape, because there is no pressure difference.

You should do this very quickly, before the toxic gas fills your room and lungs.

1 hour ago, K^2 said:

And if I get power outage, I sit in the dark.

And "I" just leave the damaged room and walk to another one.

1 hour ago, K^2 said:

On Mars, these are also your only construction options.

Mars also has a lot of carbon. Like Venus.
While Venus doesn't have metals. Unlike Mars.

1 hour ago, K^2 said:

And mining on Mars is going to be a lot harder than mining on the Moon. 

Mining on Venus is at all impossible.

1 hour ago, K^2 said:

On Mars, once you start drilling, that stuff will be everywhere.

It anyway will be everywhere. On Mars. As on Venus drilling is impossible at all.

1 hour ago, K^2 said:

On Venus, you can go 100% organic

On Venus you should fight for every liter of water.
And there is no organics without hydrogen.

1 hour ago, K^2 said:

Venus has thick atmosphere. Getting stuff to Venus is super easy.

In KSP.
To aerobrake something you have to have it enough strong, and use engines to put it in orbit, then deorbit and precisely land on an unstable lightweight floating platform during a hurricane.
Nobody will aerobrake something significant irl.

1 hour ago, K^2 said:

Landing on Mars, though? The atmosphere is too thin to properly slow you down

Tell this to NASA. Their MDRA5 includes two aerobraking modules with heavy equipment.

1 hour ago, K^2 said:

parachutes are completely useless on the final leg

Parachutes are useless for heavy landing platforms in any case, unless you want to land it on a roof or in several kilometers from base.

In Venus parachutes are even more useless, because landing zones are (see above).

1 hour ago, K^2 said:

And you can't exactly land a new module far from the base, because then you can't move it. But if rockets fail, you just bombed your own base. On Venus, any additional cargo can arrive miles away from habitats, and then be floated to the main base.

Jumping with chute from airplane on a blimp is definitely easier than on land.

1 hour ago, K^2 said:

The main theme of all of this is that on Venus you have backups and redundancy built into the environment. On Mars, there is zero margin for error. If anything goes wrong, you can't fix it.

On Venus if you miss with supplies, it will be first burnt, then crushed, then crashed.

On Mars you can at least collect the remains.

1 hour ago, K^2 said:

On Mars, radiation is a problem.

Are you aware that Venus doesn't have magnetosphere?
On Mars you at least have ground.

1 hour ago, K^2 said:

If I need a new place to grow food on Venus, I can put some air into a plastic bag

Which will pull you to the ground because the buoyancy changed.
So, don't forget to keep scissors aside.
And yes, every kg of water for it you will get by processing a hundred tonnes of "air".
So, better not throw your wastes out. This is not Mars, you should reuse it.

Do you remember that your "plastic bag" is made of hydrogen, too?
Better use a carbon net.

Spoiler

 

1 hour ago, K^2 said:

Living on Mars is like skydiving without a spare parachute.

On Mars parachutes at least work.
On Venus they are a slow way to hell,

1 hour ago, K^2 said:

The colony will survive if these shipments stop.

Without metals, without hydrogen, without silicon for solar panels, without nuclear fuel.
I want to believe.

On Mars you can have 1000 emergency warehouses with supplies, with your name written on them.

Edited July 4, 2018 by kerbiloid

[K^2]

35 minutes ago, magnemoe said:

In short setting up even an small base in Venus atmosphere require an flying aircraft carrier, that is the easy part
Recommend building one on earth first for testing. 

Spoiler

But mostly what ARS said. There are a lot of advantages to denser atmosphere.

On the matter of going there and back. Going up from Mars is a lot easier than from Venus, yes. But if you're building a colony, your first priority is getting people down. A glider will manage that just fine on Venus. Maybe you'll have a drone to catch these. Maybe you'll decide to actually build a runway. Both options are quite viable, and allow for huge errors in range even with complete power-off landing. You can also do parachute or powered landing. Plus, it really doesn't matter where you come down, so long as you are within gliding range. On Mars, missing landing spot might be ok, or it might be catastrophic if you hit a bad patch of rocks. We will lose colony ships on descent there, it's not even a question of if, but only of how many. That'd be acceptable if it was the only option, but it isn't.

Yes, ascent from Venus can be conducted using conventional multi-stage rocket. Although, I would argue that building SSTOs is probably a good idea. Because atmosphere of Venus is denser, the ascent from the same pressure altitude is actually easier, as the air is all concentrated at lower altitudes. Plus gravity is slightly lower. So any SSTO that can work on Earth will work on Venus. We have had promising projects that would do just fine. And whether hydrogen or methane, it will be easier to synth fuel on Venus.

@kerbiloid I don't think you're picturing environment of a frigid desert in near vacuum correctly if you are imagining getting ice with an ice pick. Your entire proposal is so absurd as to be meaningless.  If I bury a block of ice in a desert here on Earth, you won't be able to make drinkable water from it without a lot of hardware, which will constantly break due to sand.You will need heavy equipment to mine, refine, and purify water on Mars, all while in conditions that are dramatically worse than worst of what we have on Earth. The sand on Mars is more destructive, and cold worse than Antarctic.

The sulfuric acid from my water on Venus is removed with a still. You simply cannot compare the two.

And It's less than 1 ton per 1kg of water based on the same document. Again, this is altitude-dependent, and cloud colonies would be at optimal altitude for water collection.

Quote

Are you aware that Venus doesn't have magnetosphere?

Are you aware that there is data for radiation levels at various altitudes, and that at 1 bar altitude, radiation is comparable to Earth?

We have data on these things. You haven't even bothered to look at it. You continue on your trend of making up false facts about something and using them as arguments. That's not how a discussion works.

Edited July 4, 2018 by K^2

[magnemoe]

10 minutes ago, ARS said:

Cytherean atmosphere is much thicker than earth, you can't test something on Earth atmosphere and expect it to work on Cytherean atmosphere. On the other side, that thick atmosphere (being mostly CO2) allows normal air to be used as lifting gas, meaning balloon is much more effective there than on earth. You don't need an aircraft carrier, a balloon is enough to maintain a colony and infrastructure. As a bonus, being above the cloud layer, launching a rocket experience less drag in-flight and much easier to reach orbit, allowing a smaller rocket to lift same amount of mass compared with surface launch

i know air is an lifting gass on Venus, however I assumed it would operate in the 1 bar layer, you could go a bit deeper but you don't want to stay at multiple bar for an long time, this also make launches harder as engines will start with more drag and lots of back pressure.
As for aircraft carrier, it was something who can launch and recover two stage orbital rockets, generate fuel for them and do maintenance and repair assume this would require something like an large ship, yes lighter than an ship but still massive.  

[kerbiloid]

6 minutes ago, K^2 said:

But if you're building a colony, your first priority is getting people down.

In XVII century.

In XXI it's getting them up, and quickly evacuate.

7 minutes ago, K^2 said:

A glider will manage that just fine on Venus.

And if glider missed...
... then it should be an airplane. As this is not Mars, you can't land on any flat place.
But wait, there is no oxygen in the atmosphere, just CO2.
So, it should be a rocket plane.
So, it's a rocket with big wing, first trying to glide, then trying to launch with huge drag of the wings.
Better use just a rocket.

10 minutes ago, K^2 said:

Maybe you'll decide to actually build a runway.

It should be a very big floating island, otherwise it will be tilting every time when a glider runs along the runway.

11 minutes ago, K^2 said:

Yes, ascent from Venus can be conducted using conventional multi-stage rocket.

With fueld imported from Earth, unless all the colony will work on the shuttle refueling. Lack of hydrogen, you know.

12 minutes ago, K^2 said:

So any SSTO that can work on Earth will work on Venus.

I plus it fiercely.

SpaceX should make Autonomous Drone Blimps Airships to land BFR on them.
Later they can use them on Venus.

17 minutes ago, K^2 said:

@kerbiloid I don't think you're picturing environment of a frigid desert in near vacuum correctly if you are imagining getting ice with an ice pick.

Ok, I will use. Anyway I have to cool my reactor.

Spoiler

 

19 minutes ago, K^2 said:

The sulfuric acid from my water on Venus is removed with a still.

Optimistic.
Look at that table with Venus "air" composition once again.

[magnemoe]

7 minutes ago, K^2 said:

  Hide contents

But mostly what ARS said. There are a lot of advantages to denser atmosphere.

On the matter of going there and back. Going up from Mars is a lot easier than from Venus, yes. But if you're building a colony, your first priority is getting people down. A glider will manage that just fine on Venus. Maybe you'll have a drone to catch these. Maybe you'll decide to actually build a runway. Both options are quite viable, and allow for huge errors in range even with complete power-off landing. You can also do parachute or powered landing. Plus, it really doesn't matter where you come down, so long as you are within gliding range. On Mars, missing landing spot might be ok, or it might be catastrophic if you hit a bad patch of rocks. We will lose colony ships on descent there, it's not even a question of if, but only of how many. That'd be acceptable if it was the only option, but it isn't.

Yes, ascent from Venus can be conducted using conventional multi-stage rocket. Although, I would argue that building SSTOs is probably a good idea. Because atmosphere of Venus is denser, the ascent from the same pressure altitude is actually easier, as the air is all concentrated at lower altitudes. Plus gravity is slightly lower. So any SSTO that can work on Earth will work on Venus. We have had promising projects that would do just fine. And whether hydrogen or methane, it will be easier to synth fuel on Venus.

Yes we has tested flying airship carriers using biplanes, not orbital rockets, and all of them crashed and burned, airships has an horrible track record.
Most fails was because of weather, it looks like this become more of an problem with increased size because of wind shear this will also be an problem on Venus. 
Getting fuel on Mars would be pretty easy compared to Venus, both has co2, you can drill for water on Mars but on Venus it would be harder. 
You will need an runway or powered landing on top of an balloon, both has some danger, an SSTO will be far larger require an larger base to launch from. 

[kerbiloid]

28 minutes ago, K^2 said:

Are you aware that there is data for radiation levels at various altitudes, and that at 1 bar altitude, radiation is comparable to Earth?

From which craft?

(Don't get me wrong, I'm happy enough with Martian ground layer, and would be glad to be sure that Venus has no such problem, too.)

28 minutes ago, K^2 said:

And It's less than 1 ton per 1kg of water based on the same document.

Where?
10^-4..10^-1 %

I.e. ~1...1000 t per kg.
I take 100 t as a nice estimation.

Edited July 4, 2018 by kerbiloid

[K^2]

2 minutes ago, magnemoe said:

Yes we has tested flying airship carriers using biplanes, not orbital rockets, and all of them crashed and burned, airships has an horrible track record.
Most fails was because of weather, it looks like this become more of an problem with increased size because of wind shear this will also be an problem on Venus. 
Getting fuel on Mars would be pretty easy compared to Venus, both has co2, you can drill for water on Mars but on Venus it would be harder. 
You will need an runway or powered landing on top of an balloon, both has some danger, an SSTO will be far larger require an larger base to launch from. 

I've covered getting water on Venus vs Mars in this thread in much detail. Please, refer to that. The idea that it's going to be easy to obtain water or fuel on Mars is ridiculous. On Venus, however, you literally make it from the air. Nothing else necessary.

Weather on Venus is dramatically calmer than on Earth. High altitude, more uniform temperatures, no interference from terrain. The colony will move with the winds, there is nothing you can do about it, but there will be almost no relative wind for structures to deal with.

And as pointed out, your lifting gas can be nitrogen. It's hard to imagine something safer.

 

If you want to avoid overhead of landing and launch pads, early on you can capture gliders with drones and use disposable balloons to lift the SSTO prior to launch. Eventually, I'm expecting cities of tens or hundreds of thousands, where overhead of a runway isn't a big deal. But at an early stage, you simply don't need one and can do without.

[kerbiloid]

6 minutes ago, K^2 said:

On Venus, however, you literally make it from the air.

1...1000 t of "air" per a liter of water, after filtering out a bunch of toxic compounds volatile and not (see the table). Like drinking from a volcanic lake.

On Mars you just have to melta and clean it.

(I mean, both waters are dirty and need cleaning.)

6 minutes ago, K^2 said:

Weather on Venus is dramatically calmer than on Earth.

On ground.
Up to tens m/s where you plan to live.

6 minutes ago, K^2 said:

use disposable balloons to lift the SSTO prior to launch.

A classic idea "let's first lift the rocket on a blimp"
Doesn't work on Earth, why should on Venus?

Edited July 4, 2018 by kerbiloid