RuBisCO

It could be possible to simulate L points though while maintaining CPU un-intensive 1-body physic. All that is needed is to have L points become invisible bodies with their own SOI. Of course L1 and L2 would not be spheres but more like Disks Of Influence, so they would need to implement non-uniform gravity or more complex code for non-spherical areas of influence. At present though you can sort of simulate L4 and L5 orbits, just put a ship in a matching orbit with your body that shifted.

Imagine soon we can kill everything off without guilt, because we will retain a genetic ark of every species, so we can repopulate them at our leisure... nothing morally awkward about that, nope.

Use it or not I do not judge, and I ask the same of you, less ye be judged.

The puffy clouds are definetly an improvement! This mod is going places!

Well real-ish fuels have not been implemented for KSP, but if an engine is burning Kerosene and LOX its flame should be brilliant yellow from all the white hot glowing carbon. If the engines are burning LH2 and LO2 it should be clear blue. Perhaps this is a prelude to that. I remember the old asteriod mods, I would grabed small asteriod with KAS hooks, adjusted position with robotic arms at the end of each hook and moved the little buggers around. This Claw sounds like its going to make it way too easy. I might just want to see if I could do what I did before again with my own KAS+robotic parts ad hoc solution.

Sony is making VR goggles as well now, so if oculus does not survive through FB's digestive track, there is still hope. VR is the future, it's just 20+ years late.

Under the atmosphere of Jupiter there is not a lot of ionizing radiation... but to my knowledge this thread about colonizing Venus's clouds not Jupiter. Well we all argued with Angel that asteroids are the best candidate for colonization to no avail. Angel is dead set on living in the clouds of Venus, worse at a particular altitude for some reason.

There should be difficulty settings and expansion packs, so we can get it as cartoony or as realistic as we each want.

Why not 4 legs or 6 legs or 8 legs, then you can have legs blown off completely and still be able to move around.

Yes for the same setup at 50 km I get 298 tons for the ballons, but that is assuming the temperture of all the air (which is now 20% O2 and 80% N2 at 1.066 bar) is room temp 295 k, and the hydrogen is the same as the venus gas at 350 K, but 1/2 the mass is fine enough approximation for me. For cooling we need to calculated how much heat is coming in as watts, we then need to caculate the efficiency (COP) of a heat pump having to pump out heat over a differential of 55 K (from room temp at 295 k to 350 K outside) these parameters are very different from an aircraft carrier which does not have such an extreme difference to pump over and often has the ocean as a heat sink. We then need to take a stab at the mass of it based on existing heat pumps. I've shown the input heat is going to be phenomenal, from conduction alone it could be in the gigawatts since we are dealing with surfaces areas over 1 km^2. of course this assume perfect convection, how much convection there will be is completely unknown, we are going to have hot winds beating against the ballon due to it towing a powersystem at a lower altitudes and thus at different wind velocities causing drag on the habitate balloon. Radiative heating is not even consider but would add to heat input, we also have all the heat from light let in for plant growth. From wikipedia a real heat pump over the 55 K gradient could move 2.8-2.2 Watts of heat for every watt the heat pump consumes in power. If we scale up a home air conditioner we get between 50-100 W/kg of heat pumping and 20-40 W/kg of power needed at a COP of 2.5. If we assume the powerplant manages 100 w/kg then for a 100 kt city 20-10 MW of heat input would completely negate the reduce mass of smaller balloons in added mass in heat pumps and power plant for those pumps (weight of >250 tons). We can actually use the light let in for plant growth as the lower limit. Assuming a population of 1000 (1/4 of an aircraft carrier) and minimum of 50 m^2 of plant growth area per person, that means 50,000 m^2 of garden area, receiving 500 W/m^2 on average (1000 W by "day", 0 by "night") the albedo of plants is roughly .25, so of which only 0.5-6% is converted to bio-energy, lets use the absurdly high max of 6%: 71% of the light hitting the plants becomes heat (4% is converted via photosynthesis, 25% is reflected back out) 50,000 m^2 * 500 W/m^2 * .71 = 17.75 MW. So just dealing with the heat to grow food will negate the reduce mass of the balloons, even assuming magical perfect insulation and thus no heat input! Angel's argument is that flying higher will require twice the volume of gas and twice the weight of balloon mass, but as can plainly be seen flying lower will require so much mass in cooling system and power plant for that cooling system and insulator that having to lift all that will require in the end MORE mass then extra balloon skin and extra gas. The amount of gas required I don't think I have covered but it too is against Angel's argument: the amount of lifting gas needed to be produced per mass actually INCREASES the lower you float, at least within the range of 57 to 50 km. I calculated to lift 100 kt will require 4.1 kt of hydrogen gas and 30 kt of breathable air at 57 km, total volume being 0.2 km^3. At 50 km though you will need 4.3 kt of hydrogen and 36.9 kt of breathable air, despite the volume dropping to 0.09 km^3! This is due to the gas being much more compressed at the lower altitude from 370 mbar to 1066 mbar, so at 57 km the mass is 31 g/m^3 for hydrogen and 459 g/m^3 for breathing air, but at 50 km it is 73 g/m^3 for hydrogen and 1251 g/m^3 for breathing air! So flying lower only saves on balloon skin mass and balloon volume, but adds mass in gas as well as all the aforementioned mass in cooling system, power-plant for that cooling system and insulator. Balloon skin is going to be much cheaper to make and maintain than a cooling system, and the increase in balloon volume is a non-problem: going from 178 m wide balloons to 232 m balloons is not going to present any show stopping problems, the extra habitable area may be for the best. For 50 km we need a cooling system to remove every watt of heat produced and every watt that enters, just the heat produced for the basics likes food production will be enough to outscales the mass of balloon skin needed to fly higher. At 57 km though or a passive temperature control altitude we need no cooling system, no power for that cooling system, no insulator, we can use simple clear plastics skin. At that altitude kilometers of surface area are a good thing not bad and more surface area is a benefit not a curse, convection is great and so is conduction, all the problems of flying at 50 km cease to exist or even become benefits when floating at 57 km! A line can be dragged to balloons that are lower and that lift heavy industry (and no habitats) that can operate at higher temperatures not comfortable to humans. All the way down to power conversion systems. A line stretching from 57 to 37 would have a wind speed gradient of 25-100 m/s at 13 bars of pressure (at the bottom) where wind turbines could be (ones able to operate at nearly 300°C though). We don't need to worry about the drag causing increase convection against the habitat because the more convection the smaller the heat difference we need between outside and inside air and the lower we need to fly, as long as we stay above the altitude where the outside is hotter then the inside air.

I believe I've stated this repeatedly now. At 100 g/m^2 would be about 500 tons for 30 spherical balloons 230 m wide (volume of 6.76 million m^3 per balloon), these being 20 filled with hydrogen made from H2SO4 in the clouds and the other 10 filled with breathable air consisting of 56% Oxygen and 43% Nitrogen at 0.37 bar made from H2SO4 and nitrogen pumped straight from Venus's atmosphere. Total lift capacity is 100 kt at 57 km altitude (about the weight of an aircraft carrier.) this being the estimated altitude were the outside air will be 10°C and thus 10°C bellow room temperature. The balloons weigh about 1/200 or 0.5% the total weight, future materials could of course reduce the balloon mass but as you can see that mass is already negligible even using a grossly overestimated 100 g/m^2. There are a variety of existing plastics that could be used to provide that level of performance, be resistant to sulfuric acid and be transparent. Heck we don't even need transparency for the hydrogen balloons. I would guess PVF could do the job. yes that right: enhanced beach ball plastic! In fact a "beach ball" skin thickness of 0.18 mm (standard for beach balls, which are between 0.15-0.3 mm) made out of PVF with a density of 1.78 g/ml would weight 101.1 g/m^2 This is all calculated via spreadsheet if you want a copy.

Skylon can only lift 15 tons to orbit, so if you found a mars mission using skylon then even a Falcon 9 could do it! There are studies on fuel depos using the Atlas and Delta rockets even, I would think Falcon 9 heavy could do it too, only better.

SLS is a great idea it just came half a decade to late, the whole fiasco with Constellation verse Direct eventually ended with Direct winning (and becoming SLS), but by then the Shuttle contracts had laps, now it makes little sense to make a directly shuttle derived rocket. If Constellation had never been started and instead we had worked on making a single directly shuttle derived booster of starting lift of 60+ tons instead of the Ares I and Ares V we would likely have an SLS rocket today. Mike Griffen wagered he could get the money for a fully redesigned rockets and he lost that bet, if he had shot for Direct/SLS to begin with his chances would have been better. Now if SpaceX can come through past their delays and big talk and launch a Falcon 9 Heavy and provide it within the price range they claim, then SLS will be functionally dead. The initial SLS will have 33% throw capacity compared to the F9H, true, but it will cost many times more per launch then a F9H. Develop an orbital fuel depo system and we could launch missions to the moon an beyond with 2-3 Falcon 9 Heavies per mission for a price less then one SLS.

Well I think you mean Angel, but I provided her with scale, showing that with a pure conduction model over a single layer of the ballon there will be GIGAWATTS of heat coming through, that even with aerogel just over the layers touching the city there will still be multiple megawatts of heat and then untold more megawatts from radiative and convective heating. Angel beleives that somehow somekind of scheme inside the habitat ballon can make up for the many megawatts of energy needed to cool the city and mass of hundreds of tons of heat pumps, there is no such thing, it would violate phyics, it would bring back less energy than carnot efficency would dictate which is 16-17%. All this stubernly refused for an ideal of floating at 50 km exact, for some reason. Why? why not 40 km with a good view of the sizziling surface and clouds above, and even more lift? Why not several ballons over ranging altitude, highest at passive heating temperature for the habitate, lower ones for industry that can operate at temps between 30-200°C, power can be generated from wind diffrentials (or heat differntials, although I would guess turbines would be lighter) Why she is hell bent on putting one singular ballon right on top of the redish haze at 50 km, I don't know.

artist interpretation. You refuse to admit that at the altitude your flying all your going to see is redish haze. I'll admit I'm wrong when I'm wrong, but is it not possible your the one being stubborn about this, that you refuse to see the detriments floating at an altitude that requires active cooling? You can't make a passive heat pump that would violate physics. Certainly you can make ways to extracted energy, but cooling the city will always require energy, a lot of energy, and mass. Explain how. Aside for a complete lack of evidence present for 'how', I see no reason that a balloon at 57 km can't also be connected to harvesting equipment at 50 km or any other altitude for that matter. You your self suggest so much in generating power by taping into the different velocities of the cloud layers. Exactly! And so we need to already have a colony started before we have the infrastructure to build a colony completely out of Venusian materials. No, no its not, this is your stubbornness, not mine and I agree it is pointless to argue with you about it anymore. Why? Why is it so necessary to conserve volume, even going so far as to replace it with heat? Why can't they simply build bigger volumes? 100 kt in 30x230 m balloons sounds pretty big to me, so no I don't think I'm stuck in a first mission mindset. So? Well then might I recommend finding a way to live on the sun? Venus Revealed by David Harry Grinspoon. Yeah in the UPPER CLOUD layer, you want to live in the LOWER CLOUD layer

So has anyone made a mod or .cfg that allows you to use KAS boxes to transport lift support?

If reducing the volume adds MORE cost in technological solutions then higher volume IS THE SOLUTION! The cost of lifting the payloads does not just include gas and balloon skin mass but also your schemes for active cooling, for balloon construction, etc, if those schemes are more expensive then simply flying higher and achieving passive temperature control then they are not viable solution and just flying higher is the best solution. There is no reason we should not fly higher other then increase volume and gas required, which are easily solvable problems, there are many reasons we should not fly lower though. Why would you want to covert all the hydrogen in Venus? The energy costs of keeping a city cool, building insulator and cooling systems is going to be more than just making more lifting gas. My point has been just refrigerating the city its self will require a lot of energy, that energy can't be gained back by any scheme in any significant amount and doing so adds only more mass. The heat difference of the city can't be used to provide energy, it must require energy, large amounts of energy by the laws of thermodynamics. Your city will be receiving significant amounts of heat via light (if its to grow plants) heat from industry, heat from conduction, convection and radiative heating from inside and outside the balloon skin, and no scheme is going to reduce this significantly without requiring a lot more mass and even violating thermodynamics. The technological solution you seek is to fly higher and achieve passive temperature control. You have been arguing that we should fly at an attitude that needs active cooling, I've been arguing we need to fly at an altitude that needs only passive cooling (to be more exact needs only passive heating) what ever the altitude may be, the lower the better, in fact if the detailed charts are wrong at at 50 km it is 0ºC that only makes my argument stronger for we need even less lifting gas and balloon capacity to maintain passive cooling/heating altitude. So if we build balloons on the surface, we need to already have an industry on the surface for building balloons, probably highly or completely automated... why send people? What I'm proposing is we don't start with a surface infrastructure, we “land†the balloons first long before we build them at venus, and we build them at altitude forgoing the need to build balloon material that can survive being created and constructed at 500ºC and 92 atms of CO2. Its not as much of a problem as active heat pumps. If you fly higher the problem is solved, 'technologically' by gas production. There no reason to do it the hard way when the easier way is already technologically available and cheaper and better. The volume difference is irrelevant: gas is cheap and can be made at Venus, but balloon skin, insulators, heat pumps, power plants can't and must be flown to Venus. You need to consider how to construct your cloud city, first a set of balloons are sent to Venus that only need enough gas to float themselves and a small power plant, electrolysis/atmosphere extraction kit for extracting oxygen, if we assume 51 tons of balloons plus 49 tons of the aforementioned critical starting cargo then we need to lift only 100 tons initially, even though we have balloon capacity to lift 33 times more (assuming 100 g/m^2, 57 km altitude). What this means it needs only "land" with 4.6 tons of hydrogen gas (or ~10 tons of helium) in order to float at 57 km. As the balloons fill more mass can be added via heavier then air cargo ships that fall via paraglider into the grappling line. The initial lifting capacity is 100 tons, but when completely filled the final lifting capacity of 51 tons of balloons at 100g/m^2 and 1/3 filled with breathable air, would be 3.3 kt. The paragliders from each cargo ship could potentially even be reprocessed into more balloons, but again we did not bring gas for them, no gas at all in that case, but instead we make all the lifting gas at Venus. If we go for 50 km or an altitude where we need active cooling we would reduced the amount of hydrogen needed initially in half, but that only a few percents the total mass so we gain little, and yet we need to add the mass of a cooling system and power plant for that cooling system. So in conclusion the mass of the gas or volume of the balloon is not counted because we don't need to land with it, only a small fraction of it, the rest can be generated at Venus easily, yet the mass of a cooling system must be counted because we can't generated it at venus. You could argue that we could with an established infrastructure on Venus build balloon skin, insulators, cooling system and power-plant initially, but this is a chicken and egg problem, for we need all that already to have the infrastructure to build all that. Unless of course we can build all that on the surface of Venus robotically, but if we do that it begs the question of why have humans on Venus (or in its clouds) to begin with. But Verena and Pioneers probes showed it it be mostly haze, not clouds per-say, the particle sizes are too small throughout to produce clouds as we know them, fluffy and with different form. I've been in fog and you can't see "other clouds" inside fog, all you see is things further way getting foggier until they disappear in blankness, the view can be eerie. Of course a Venusian cloud city would have nothing else outside to look at so it would be surrounded by blankness. To get to a "cloud" layers where A) the clouds appear white and not yellow or orange or red and where differentiation can be seen and even C) blue sky's above, would require floating HIGHER than 50 km, even higher then 60 km, as close to the top of the upper cloud layers as possible. The altitude your proposing would be very dense fog/haze and red shifted with all the bluer spectrum light scattered by the higher layers making for an orange or even red sky, highly unpleasant sight to most people other than satanist(?)

While we are at it lets have their fingernails grow out... pass.

Well these ideas sound fun as heck, remember that just a few kilometers drops you will reach uninhabitable temperatures. If you have a parachute that reduces your fall speed to 2.5 m/s and you have 5 kilometers untill you boil to death, then you have 2500 seconds, or 33 minutes to get picked up before you die of heat exhustion. I guess somekind of drone could fly down and pick you up. I think the simplist solution is to always have at least one line tieing you to the ballon: mountain climbs don't usually bring parashutes, so if you slip and fall now your just dangling from the ballon and if strong enough you could pull your self back up, maybe a crank could help you.

The solution is the fly higher and have passive temperature control. Sphere simply to make the calculations easier. Anything other then a sphere will have greater surface area per volume not less, your surface area is order of magnitude to small. Again for a ballon capable of lifting a “City†we are talking about kilometers^2 surface areas and thus dozens of metric tons of aerogel, with volumes that are impractical to ship to venus. and I said that the heat produced from optical light alone will be devastating for your scheme. So again you have massive energy inputs, you need to pump out all the heat. Yeah the technological solution is the fly higher, its a very simple, easy and achievable solution. No its very cheap, we can make it easily from the sulfuric acid of the clouds. With a simple electro-reduction cell we can convert H2SO4 to H2O and SO3 and then H2O to hydrogen and oxygen (we could even do it all as one step). It would in fact be energetically less costly then making O2 for CO2 (well actually 2CO2->O2+2CO would require less energy, CO2->O2+C(solid) would be more energy expensive, but the CO is relatively useless and best dumped), so to make ever m^3 of breathable oxygen we have 2 m^3 of hydrogen “waste†might as well use it considering it is the best lifting gas there is. No it would require more energy to make aerogel then to make O2 and H2 from sulfuric acid, making solid carbon is not an efficient process, then you need to add in the cost of making it into an aerogel, worse carbon aerogel is very flammable and you have this with an oxygenated atmosphere on one side, not good. Then you need to consider the machines need to make sheets of it and stitch it into fabric. Well I already have the solution: fly higher. Think of it this way, you want to go outside right, would it not be better to go outside to cool air at 10°C not 55°C? Would it not be nicer to go outside to a white sky and not a yellow or red sky? And as my cacluations show the mass ratio is tiny, the difference for a 100 kt city would be 0.25% that is the weight of the balloons nearly double to take up a pultry 0.5% of the total cities mass. The weight of the internal gas is not counted as we don't need to bring that to Venus, nor do we need to bring the mass of a cooling system, which would negate the advantage of flying lower. Altitude control means temperature control (As Dodgey pointed out) it provides a very elegant and simple solution to controlling temperature. As long as we can maintain an altitude where the outside temperature is a few degrees lower then the inside temperature we don't need to worry about a cooling system or schemes. During the day the passive temperature controlled balloon on versus can gain lift by absorbing some IR and optical energy from the ambient light, and at “night†the habitat air would cool and the balloon would lose a little altitude until the temperatures and lift equalized. No power is needed, engineered right the balloon would always maintain habitable temperatures without the need of any work (electrical or mechanical) How does this translate into fluffy clouds being visible verse a white/yellow/orange/red abyss of haze? Or was this about currents being navigable?, how is this evidence for either? Again Carnot efficiency means we can only gain back a faction of the heat energy as any kind of useful work, far more energy will have to be spent just pumping out the heat, and getting an energy back will only increase heat transferring not reduce it! In a spacesuit you would have hours for someone to get you, heck with a propulsion pack the chances of being stranded afloat in space are very low. In the other case you have a constant force pulling you down at ~90% earth gravity into a real hell.

Well I apologies I don't mean to be confrontational, I am mearly disagree with tiny part of AngelLestat premise, the nominal altitude of his "cloud city", if Angel' wants to say I don't understand her scheme or thermaldynamics, we can leave it at that then, clearly on this point not further discussion can be made.

By all means get a second opinion! The principle is the same inside the cloud city your describe, only inverted, but it most certainly at those sizes will be internal convection and winds. I'm not sure we are arguing about the same thing, I'm not speaking of temperature difference, I'm speaking of how much power (energy) you can get out of such a system. How? The city magically stays cool? Sure the hot air will rise, but that not the problem, the problem is how do you expect to keep the city cool with the outside so hot and with hot air circulating all around it? nylon is not going to survive contact with concentrated sulfuric acid, it will dissolve very rapidly! Or is this one of the many internal insulating layers your speaking of? Your not understanding what I'm saying, how much more will having said layers and vents and heat pumps, etc, etc cost? Is it really worth it not to simply fly higher and not need any of that? … where is the cool air coming from that transfer around the city? 1/3 the surface area of a sphere with a radius of 365 m (a balloon capable of lifting 100 kt, at 50 km height with ~0.5 kg of lifting force) is 1.7 km^2, with 2 cm thick aerogel that is 34500 m^3, aerogel weighs 1 kg per m^3 so that is 34.5 tons of gel, about the weight of 172 people. Actually that not much weight compare to the lifting force, but how you plan to fold and send something that is 34500 m^3 to Venus is beyond me. Your common sense made you think 34500 m^3 of aerogel would weight less then a single person, over 2 order of magnitude wrong, so no thank you, I'm going to stick to testing every idea rather then trusting a guess. No I was not speaking of infrared light. I was speaking of optical light: we need to let in some optical light for plant growth, those plants will convert almost all that light into heat, that heat must be pumped out. No I'm not saying such a thing, I'm saying you need to spend energy to keep the city cool. I understand the laws of thermaldynamics. Your city needs to spend energy to keep cool, your circulation system will do nothing to change that fact, it may honestly make it worse by circulating air and increase convective heat exchange. Considering the amount of air and the surface area your dealing with, you will have to spend mega to gigawatts of energy to keep your city cool. Your not understand what I'm saying, or thermodynamics, you most spend energy to pump heat from a lower temperature area to a higher temperature area, no matter the mechanism, no matter some apparent average temperature. No the equilibrium state would be no gradient and no heat difference, stratification is a result of temperatures being out of equilibrium. How? Can you put a price tag on m^3 of gas? We can make gas at Venus, we have to take to Venus all the mass of balloon, insulators, heat pumps, radiators. Lets me compare, I'll make a city at 57 km, 100 kt, that would be ten breathable air balloons 235 m wide, and 20 more hydrogen balloons the same width, Each balloon would weigh 17 tons, totaling 520 tons, that is about 0.5% of the total mass of the structure, of which none of that is in the form of AC system, or insulators or radiators or power plant for said AC system. Seems reasonable to me. If we drop to 50 km the balloons drop in size to 176 m in width, and total balloon mass is 292 tons, that is a weight savings of 228 tons, or about .25% the total mass of the structure. So to drop down in altitude we gain 0.25% in structural mass, less then a percent, then we have to add the mass of insulator, (20 tons, aerogel 2 cm, 1 kg/m^3 insulating just the habitat balloons) the mass of an AC system, lets assume .1 kw/kg for it all and a very optimistic 2 MW needed, that is 20 tons, and then a powerplant for that lets go with a nice 100W/kg (four times that of terrestrial wind-turbines) and that is 200 tons, total is 240 tons and look at that with very optimistic assumptions we make up the weight advantage and then some in insulator, cooling system and powerplant for cooling system. What evidence? Nitpicking, heck we have yet to talk about altitude, what is the minium orbital altitude of venus? I would bet with its atmosphere that altitude is much higher than earth, and thus the orbital energy is higher. ~90% may in fact be a underestimate. Not as long as it would take to make a colony on venus, we are talking about 22nd century at least right? And yes if we have such robots it does bring into question the whole idea of sending talking monkeys into space. Doesn't sound very habitable, heck with "appropriate clothing" work in the vaccum of space at zero gravity is not so bad either, at least one wrong move won't send you falling straight into a literal hell. What evidence? The venara and pioneer probes clearly show alot of haze, show a shifting into the red the deeper into the cloud layers. That just an artist interpretation, of course he's not going to paint a city afloat in white blankness or worse in yellow or red haze.

And again that purely a guess. I've provided a link and quote, what more do you want? And how much energy is required to maintain the stratification? A hot air balloon burns a lot a fuel for example. I'm really baffled at how you plan to produce this hot air, the ballon must be insulated to maintain a cool city, the air that would flow up would be warmer then the city but not hotter then the outside air, if you let in heat to heat that air then via convection its going to add heat your city, your going to need to pump out more heat. The energy costs are going to be great. You want to know how much energy you and pull back out of a heat gradient in a column of air, that how much. No I’m not, I don't see how you can claim the costs of maintaining your city at a cool temperature are going to be light. Balloon fabric is pretty dam light, adding more layers to it is going to make it not as light, it is extra weight. Weeks or months? Where are you coming up with that? The AC has to fight the heat of the city, it has fight heating for convection inside the balloon, it has to fight heating from outside! I never said UV, where are you getting UV? The graphic does not make physical sense. I'll make it simple for you, forget for one second about all the insulation and the different IR layers, AC, etc. No this makes no sense, energy must be spent to maintain any temperature difference anywhere, averages does negate that. I'll make it simple for you: you must cool the city, to do that you need to add weight and complexity in insulators, heat pumps, radiators and power plants, there is no way around this, period. 1 kW, that is impossible, you have envelope that is has a surface area of kilometers holding out a temperature difference of 55 K, there no way could have only 1 kW of heat entering! I've shown through conduction alone the heat entering would be astronomical, you would need THICK insulation to hold that back or worse a vaccum-dewar. Impossible! That would violate physics, you must PUMP out all heat that enters, you can't radiate it back out because the radiation you let in will be greater. Again to maintain any temperature below ambient will cost energy, let alone absolute zero. No you would not. You need to add the cost of energy from heat pumps, and the heat from that energy. Surrounding your self with air that the same temperature as the outside does not magically make those energy costs disappear, now you need to keep cool from the air you surround your self from. yes, it clear where the flaw your logic is: average temperatures does not allow you to violate thermaldynamics: to maintain any temperate difference anywhere requires energy. yes it can be easily solved: float higher! All those problems disappear if we do that, but your obsessed with floating lower for some reason. Again I point out more gas costs a lot less then all the complexity your adding. Assuming Venus’s air currents are navigable. And I say again that does not add up to much savings. Venus at a diameter 95% that of earths, and a gravity 91% that of Earths, if we assume equal proportions then that means an orbital velocity 86% that of Earths or 7-8 km/s! A) you could have robots do that. going outside at 55ºC into acid mist is not going to be something people want to do for fun. C) if you want to fly we could build habitats in lunar lava caves or asteroids and you can strap on wings and fly. Frankly hang on to a balloon in the middle of complete blank whiteness does not sound very fun. yes complete white blankness, yes very bright, complete white blankness, no you would not see the surface, in fact as your get lower in the clouds whiteness would give way to yellow, followed by red and then you would see the surface below, at the altitude you describe the sky might in fact have a **** color or perhaps an unappetizing orange, perhaps darker below then above. Seeing fluffy white clouds and blue sky is unlikely.

Human muscles must consume energy just to remain contracted (with exception of smooth muscle which can "lock") if we assume human human skeletal muscles must spend the same amount of energy to remain contracted as to contract, then the determine the energy to hold a kilogram above the around is nothing more then the force of that kilogram (~10 newtons as stated above) per second. Now comes the tricky part, convert newtons to joules or watts.