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Engineering a vacuum zepelin?

Myriad said:
I know that materials sufficient to make an evacuated sphere with a shell light enough to self-lift don't exist yet.

But can anyone give me an estimate of how far off existing materials are? By what factors do, say, steel, titanium, glass, and composite carbon fiber fall short of the mark?
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Together with my coauthor, I've spent quite some time "engineering a vacuum balloon":-). Our conclusion: difficult, but possible with current materials. Although an evacuated homogeneous spherical shell cannot be both light enough to float and strong enough to withstand atmospheric pressure, no matter what existing material you use (e.g., diamond's elasticity modulus is at least three times too small), a sandwich shell can meet these conditions with a reasonable safety factor. See details in our US patent application 20070001053 (11/517915) (you may google "layered shell vacuum balloons")
 
akhmeteli said:
Together with my coauthor, I've spent quite some time "engineering a vacuum balloon":-). Our conclusion: difficult, but possible with current materials. Although an evacuated homogeneous spherical shell cannot be both light enough to float and strong enough to withstand atmospheric pressure, no matter what existing material you use (e.g., diamond's elasticity modulus is at least three times too small), a sandwich shell can meet these conditions with a reasonable safety factor. See details in our US patent application 20070001053 (11/517915) (you may google "layered shell vacuum balloons")
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Unobtanium!!!!...meh
 
Hi akhmeteli, and welcome to the forum!

That's a very interesting approach. (Summary: the sphere is made of two similar concentric thin strong shells. Between the shells, and attaching them together, are walls oriented along radii of the spheres, forming a honeycomb-like array of hexagonal cells. This provides stiffness against buckling. The recommended materials, though available, are a bit exotic, e.g. diamond-like carbon.)

I think you'll find you'll need a dozen pentagonal cells to fit the hexagonal array around a sphere.

Given the competition by other technologies such as conventional balloons and drone aircraft in the most plausible utilitarian applications (such as aerial surveillance), have you considered manufacturing them in, say, a 1/2 to 1-meter outer diameter, as high-tech scientific novelties? Would that be possible? That might be a stepping stone to more utilitarian versions.

Respectfully,
Myriad
 
Myriad said:
That's a very interesting approach.
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Thank you very much for your interest.

Myriad said:
(Summary: the sphere is made of two similar concentric thin strong shells. Between the shells, and attaching them together, are walls oriented along radii of the spheres, forming a honeycomb-like array of hexagonal cells. This provides stiffness against buckling. The recommended materials, though available, are a bit exotic, e.g. diamond-like carbon.)
Click to expand...

Or, say, boron carbide. As I said: possible, but difficult.

Myriad said:
I think you'll find you'll need a dozen pentagonal cells to fit the hexagonal array around a sphere.
Click to expand...

I don't think this is a major difficulty, as honeycomb can be flexible. If you google beneflex honeycomb, you may find a picture of steel honeycomb folded into an 11 inch diameter sphere.

Myriad said:
Given the competition by other technologies such as conventional balloons and drone aircraft in the most plausible utilitarian applications (such as aerial surveillance),
Click to expand...

Vacuum balloons have some obvious drawbacks and some strong points, such as simpler altitude control. I think they will or will not find applications depending on their cost, but even if they will be just a "trophy on the wall", it would be nice to show that this 350-year-old idea is technologically feasible.

Myriad said:
have you considered manufacturing them in, say, a 1/2 to 1-meter outer diameter, as high-tech scientific novelties? Would that be possible? That might be a stepping stone to more utilitarian versions.
Click to expand...

The problem is intracell buckling (see our application), but there are some ways to overcome it and produce, say, a 20 cm dia vacuum balloon. Actually, I have just ordered some R&D in this direction, but the road ahead is very long, so don't expect any news soon:-)
 
Well.

That was gosh-darned exciting.

I welcome the new blood,

welcome, new blood.
 
If they can be produced they could do a similar job to a helicopter. Or how about a very cheap substitute for a satellite in geostationary orbit? Get one in high altitude, with solar cells (these would be able to produce more power higher up than at sea level) for fuel and it could broadcast TV and radio over a wide area. Not to mention being a tower for mobile phones.
 
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