Absolutely. However my focus is still on track records vs OP's assertion, and the our longest jaunt in the Venusian atmosphere (A balloon probe) was under a day.
Even so, I fully believe we're capable of building a floating habitat on Venus, but I think it'll be like our Antarctic bases: A valuable scientific outpost in a hostile environment totally dependent on outside supplies, and not a frontier for human colonization.
This is what is ultimately compelling about Mars, we can live there, thrive there, and eventually, breathe there.
And why wouldn't a Mars base be dependent on outside supplies? Mars is still a hostile environment.
So one thing that makes Venus attractive is the atmosphere contains everything needed to make breathable air, water, fuel, and plastics[0]. On Mars, water is hard to obtain as one has to extract it from dirt. One of the issues with systems that process granular materials is that they don't work very well. They are over designed, always break down, and typically operate at 63% of their design capability. Oh and scaling laws don't apply to granular materials as they do for fluids, making scale up expensive.
Mining the atmosphere of Venus could be a much simpler process[2]. Currently, liquid oxygen, a product which we 'mine,' from Earth's atmosphere is about as expensive per ton($175) as concrete. In addition air separation plants require so little maintenance that they are often unmanned. At the very least most places that process granular materials require a person to periodically unjam things.
Early colonies on Mars can make much of their structures out of mud bricks, and shortly thereafter out of more refined concrete, steel, and glass. Yes, the machinery to make these materials will break down occasionally, same way you'll occasionally ruin an axe while chopping wood. In which case you'll fix your axe or die in the winter.
On Venus, you will be importing every ounce of steel, glass, and soil you need for a long, long time, because what's accomplishable with a shovel on Mars will require the Venusian equivalent of an oil rig to reach down to the surface and bring resources back up.
You will have to pry every square inch of livable space from Venus, much of it with imported materials. That is not a colony, that's an outpost. (and to be clear, an outpost I think we should have)
But that's the near term game. Show me a feasible plan for terraforming Venus and I'm all ears. Ultimately what makes Mars more appealing is that ALL of the land will eventually be habitable with protection in simple structures that provide shelter, some sort of air processing, a window or two, and maybe a fence to keep your dog from digging up your neighbor's yard. Where as on Venus humanity will be stuck in manufactured bubbles for millennia.
A Venus settlement requires flying cities. I have a hard time imagining how anyone thinks that's easier than a greenhouse on Mars.
Wiki says:
> Furthermore, water, in any form, is almost entirely absent from Venus. The atmosphere is devoid of molecular oxygen and is primarily carbon dioxide. In addition, the visible clouds are composed of corrosive sulfuric acid and sulfur dioxide vapor.
It's my understanding that while we can turn Earth into a pretty hazardous place that we do not have the total carbon required to re-create the exact venusian environment on Earth.
Your point still stands, however, regardless of exaggeration :(
Most of this past is incompatible with human civilization, as we know it.
For example, many scientists believe that the Permian extinction happened due to a rapid release of greenhouse gases, and rise in temperatures - by ~6C. 95% of the Earth's species were wiped out in a few years.
These kinds of events aren't trillions of dollars of damages. They are billions of human deaths, as ecosystems collapse, as the tropics and subtropics become uninhabitable.
Unfortunately for us, while CO2 may not cause such a drastic change in temperatures over the next few decades, methane release very well might.
3. It has an atmosphere that can shield you from radiation and meteorites.
4. It's closer to the sun, so solar power works well there.
5. The atmosphere makes available a variety of useful elements that would be difficult to get on most other parts of the solar system.
6. As it happens, there's a fairly happy medium in the atmosphere in which pressure is something generally like Earth pressure and temperatures are something generally like Earth temperatures and that part is also above most of the really corrosive stuff in the atmosphere.
The downsides:
1. You have to develop floating habitats. Those seem possible in theory, but would certainly be an engineering challenge, to say the least.
2. Every element that is not prevalent in the atmosphere of the planet (such as, for example, every metal) is wildly inaccessible.
3. It's a deep gravity well to get into and out of, and also you'd have to land and launch from flight, which is another big engineering challenge.
The flying fortresses is one thing, but not being able to get at solids to build with necessitates all materials coming from other planets. That would make it extremely expensive to grow beyond a non-permanent establishment.
The solar and gravity advantages seem relatively small. The distance is on average 1.5 times as large, which I'd guess is not a major difference in the kind of planning you have to do for the trip.
So you need the same life support as you need on Mars (enclosed space with atmosphere to breathe in, water, food) plus a couple of extra downsides. But as a bonus you get radiation and meteorite protection. That doesn't sound any easier to me overall.
I'm pretty skeptical about the possibilities of colonizing Venus. I think you're underselling a few things, though:
1. We don't at all know what the gravity advantage is. It might be a net disadvantage -- like, maybe there's no real advantage of earth gravity, and it makes launch and land more difficult.
But, on the other hand, maybe 10 or 20 years of Martian gravity causes disastrous health consequences for humans. We don't know! We're pretty confident that 10 years of zero gravity would cause disastrous health consequences. It is reasonable to imagine that Martian gravity would be a lot better. On the other hand, it would also be reasonable to imagine it wouldn't be enough better.
Venus gravity is pretty clearly safe for humans.
2. There are a lot of advantages to being surrounded by abundant gasses that you need to create your own atmosphere, and also to have a much less than 1 atmosphere pressure differential between your hab and your surroundings. On Mars, you could mine dry ice to replenish your atmosphere, but only in some areas, and with a lot more infrastructure than it would take to suck in some Venus atmosphere and process it into breathable atmosphere.
3. Radiation protection is a pretty big deal for long term habitability. Like, it's not necessarily a giant problem for a scientific outpost, but if you want human habitation to cover hundreds of square kilometers and be viable over centuries, how are you dealing with the radiation on Mars? Is everything subterranean? (subarean?) That's a huge amount of additional effort.
Regarding point #3, you have to have an atmosphere container in the first place (unless you atmospherize the whole planet), so the top layer of that might as well include radiation protection? Though I'm not sure what it takes to filter out most stuff while letting through visible light.
