Quote:
Originally Posted by m1omg
You never heard about deep sea exploration?Pressure on Venuse is like the pressure in the 1 km depth of the sea.It will stay anchored like a deep sea habitat.And batyscape get humans to the depth of 11 km and that wessel survived it without problems.The pressure on the Venus is not as high as you may think, in the laboratory condition there were created much higher pressure, and pressure 11x than on Venus is in the Marianic Abyss - even multicellular life survive there, under 990 bars!
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The
Trieste, the only manned sub to visit the Challenger deep, had a spherical pressure vessel 6.5 feet in diameter. A vessel designed to handle only 90 atm on Venus might not need to be that over-engineered, but it would require engineering beyond that of most military submarines, which reach maximum depths of around 800 to 1000 ft instead of the equivalent pressure depth of 3300 ft. (BTW, the
Trieste did have problems, one of the outer lexan window panes shattered under the pressure. Also, the depth you referr to is the Marianas trench, not an abyss. Abyssal plains are flat and relatively shallow. And though there is life, even vertebrate life, in the ocean depths, those pressures are incompatible with human life.)
A sphere, instead of a dome, would be the optimal pressure vessel geometry. This isn't impossible, and a spherical shell also has the benefit of having the smallest surface area to volume ratio, meaning that insulation is more effective. It would also maximize the strength of the pressure hull, but a dome would be vulnerable on it's flat underside or the seams to it's foundations. Remember, fluid pressure works in all directions, not just downwards.
If you wanted to design a surface colony with a habital volume it would be so large as to make negative or neutral bouyancy incredibly expensive to achieve. Perhaps you could build such a heavy structure on Luna or Venus from your expensive, exotic and fragile materials and anchor ballast and then move it to venus, but it would be incredibly heavy and require massive rockets to lift it even from the lunar surface. Emplacing a ballasted surface colony structure onto the venusian surface would require enormous retro-rockets because aerobraking would risk disintegration from thermal and acceleration forces and either method could result in damge to the internal aerogel insulation from acceleration shock.
A better idea would be to build the shell light and let bouyancy float it in the venusian atmosphere and then add ballast that is gathered from the surface of Venus or sent from another solar system body like Luna or Mercury (which would still be expensive). At this point you've basically designed a floating city that sinks and is more dangerous to live in. The surface colony idea doesn't argue against the idea of floating cities on venus, it argues in favor of it and practically requires it.
Take this idea. Design a surface habitat/factory that looks like the
Titan A.E. from the movie of the same name. It's a sphere with multiple hollow legs that could house retro or ascent rockets or ballast or elevators to the surface. Painting the outer hull white probably couldn't hurt, and might help reflect thermal infrared radiation, but convection/advection and conduction would probably result in the outter pressure hull rapidly warming to ambient temperatures anyways. White paint pigments are often titanium or lead. You might just use solid titanium alloys anyways, and the hull might naturally accumulate lead frost if it's on the surface long enough.
I'm not against the idea of surface structures on Venus. I think it'd be necessary to have small habitats for mining operations and for research. However there is no need to place colonies on the surface when it is safer and cheaper and easier to place them in the clouds.