Insane idea (Score: 2, Interesting) by firstname.lastname@example.org on 2014-12-22 19:10 (#2W98) The cloud deck just happens to start at the postulated 50 km, and those clouds are composed of SULPHURIC ACID. How is the structure, necessarily extremely lightweight, going to withstand that kind of environment? There are also very high wind speeds.On the surface, the idea is tantalizing, but even a cursory review of some of the gotchas pretty well relegates it to pure fantasy. Re: Insane idea (Score: 1) by email@example.com on 2014-12-23 02:23 (#2W9N) Many plastics are resistant to sulfuric acid and for metals there are coatings and/or passivation techniques to reduce corrosion. Also "lightweight" is relative since the atmosphere is hundreds of times as dense as Earth's. Re: Insane idea (Score: 2, Insightful) by firstname.lastname@example.org on 2014-12-23 10:49 (#2WA5) Generally you are right. Sulfuric acid can be handled just fine.... under normal conditions on Earth. But on Venus? Constant high temperatures? Hard UV radiation? I'd say this rules out most normally usable plastics. Before people are put into such a balloon, I'd like to see them at least for a few years floating over Venus... UNMANNED. Re: Insane idea (Score: 2, Interesting) by email@example.com on 2014-12-24 18:45 (#2WBN) If the atmosphere really does offer good protection from radiation at that altitude, there should be plastics that can handle the UV. These wouldn't be the everyday plastics that make up your deck furniture, but there are lots of plastic additives that can modify the UV stability of a polymer without changing its performance. Re: Insane idea (Score: 1) by firstname.lastname@example.org on 2014-12-26 07:39 (#2WDC) Different kind of radiation. Earth's atmosphere does a very good job to protect us from cosmic and gamma rays. That's great since those are the biggest problem. And that's were the real value of the protection of Venus' atmosphere lies. Earth's atmosphere also protects us from UV rays, but with less efficiency the lower their frequency is. According to the article Venus gets 40% more solar energy than Earth at the same height. So I just assume, that Venus also gets 40% more of hard UV light. When it comes to radiation exposure for the crew or instruments, this does not matter at all. Even hardest UV light is that easily blocked, that this aspect does not even require a special thought. However, UV radiation ages plastics. Sure, it won't be the everyday plastics, which make up our deck furniture. But with much stronger UV radiation, greater heat, and perhaps exposure to sulfuric acid it is not the everyday environment. Re: Insane idea (Score: 1) by email@example.com on 2014-12-26 16:14 (#2WDQ) I know the difference between the energies of different ranges on the EM spectrum. I also know More than a little bit about oxidation and the effects of UV on plastics. The properties of the average plastics we use in daily life are usually a balance of desired performance and affordability. With this project being an important scientific endeavor, I don't think cost will be as important a factor. That's all I'm saying.