Insane idea (Score: 2, Interesting) by email@example.com 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 firstname.lastname@example.org 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: 1) by email@example.com on 2014-12-24 07:35 (#2WB4) I guess you COMPLETELY MISSED the point of these aerostats floating at an altitude where the Venus atmosphere is exactly the same as it is at sea level on Earth. Re: Insane idea (Score: 1) by firstname.lastname@example.org on 2014-12-24 07:48 (#2WB5) Same pressure. And only 75 instead of462 degrees celsius. Certainly not same composition. This does not make it 'the same as it is at sea level on Earth'. And it might not have the heavy concentration of sulfuric acid as on ground level, but is the atmosphere in 50km height totally free of it? Re: Insane idea (Score: 1) by email@example.com on 2014-12-24 17:47 (#2WBK) Correct; if pressure is the same (1.0 at 49.5 km), and temperature is essentially the same (20-37C at 52.5-54 km), then density is 1.5, since the composition is essentially pure carbon dioxide. The buoyancy of an air-filled aerostat is then 0.5, compared to about 0.9 for a helium-filled aerostat at sea level on earth.That necessitates the structure of the aerostat being extremely lightweight.