Gonflab it all to heck!
A vacuum balloon is a good idea but we don't have meterials strong enough to make one yet...A solar-hot-air dirigible is also a good concept but impractical for commercial flight because they can not stay permanently aloft using only solar energy for lift.If the hull of this solar-ballon were double-walled though, with a thin valved waffle pattern between the walls, then a partial vacuum could be maintained between the two which would insulate against any heat loss gained while the sun is shining.
These balloons would not stay aloft indefinitely, but only having to augment the miniscule heat loss would be very inexpensive, especially if the "re-fueling" came from solar charging ground based collectors.
My appologies if this exists, I can't find anything combining these solar and vacuum balloon concepts together.-- 2 fries shy of a happy meal, Dec 11 2012 Sounds like first class accomadations - they'll need a restaurant R_2eA_2eR_2eE_2e_20S_2eT_2eE_2eA_2eK_2e [normzone, Dec 11 2012] Vacuum insulated panel http://en.wikipedia...uum_insulated_panel [spidermother, Dec 12 2012] I'll buy my ticket now before the line gets too long! [+]-- xandram, Dec 11 2012 This one actually seems feasible!
The //partial vacuum// may be false economy, though. Since conductivity is proportional to absolute pressure, and structural requirements are proportional to gauge pressure, you may get more bang-per-buck as you approach a hard vacuum.-- spidermother, Dec 12 2012 Cool links.It sounds as though aerogel would be a good choice for membrane separation but I'm having a hard time understanding whether the light scattering properties would make it inefficient at letting the right spectrum of light through.
When I was looking up Aerogel this quote from Wiki made me laugh:
_Aerogel was first created by Samuel Stephens Kistler in 1931, as a result of a bet with Charles Learned over who could replace the liquid in "jellies" with gas without causing shrinkage_
Which begs another question I can't seem to find an answer to; (probably just another non-question really), would it be possible, since shrinkage is not a factor, to replace the liquid in "jellies" with a hard vacuum instead of a gas?
Is that even a viable question?-- 2 fries shy of a happy meal, Dec 12 2012 What [Kansan] said. Although technically, liquids do not escape as gases to create aerogels; supercritical fluids do.
Also technically, liquids are not directly replaced by gases; liquids are replaced by other liquids, which are made supercritical then allowed to expand into gases. So yes, it's something of a non-question.-- spidermother, Dec 12 2012 You had me at "Gonflab it."-- Letsbuildafort, Dec 14 2012 random, halfbakery