Let's assume for a minute that money was of no concern. If one has a 10 MPa external environment and needs to have vacuumed-out spheres (or 1 atmosphere, close enough to call vacuum) inside of that environment. In particular, I was thinking of a sandwiched lattice of maraging steel, with it's conveniently high 2.6 GPa yield strength as a solid sheet, but its shockingly typical 210 GPa Young's modulus, also as a solid sheet. The problem is that the wall thickness necessary to make it survive the compressive load is very thin. A sphere a meter in radius need only have something like a 2 mm thick wall to support itself against the intense pressure, as 2.6e9 pascals * 0.002 m * 2 * pi * 1 m / (pi*(1 m)^2)=10.4 MPa. but the wall thickness necessary to prevent it from buckling, given for an (extremely optimistic) ideal spherical object by: 2.1e11 pascals * 2 * 0.002^2 / sqrt(3*(1-0.26^2)) = 1.005 MPa. So of course, looking at the formula for stiffness, I thought "what if I could make it thicker but keep the same mass of it in order to increase the stiffness independently of the mass?" I.E. I want Pterosaur bones made of rocket-grade steel. So I suppose my questions are: #1. Is making a maraging steel (or similar material) foam sandwich within the current state of the art? Is it emerging technology? Is it something speculatively possible in the relatively near future? Or is it totally fanciful magitech? #2. Would the mass-specific yield strength match that of solid steel? If not, how much weaker would it be for the foam? #3 Would the mass-specific young's modulus match that of solid steel? If not, how much weaker would it be for the foam? #4. If it isn't possible or it wouldn't be useful, what are some other ways of preventing a sphere or a tube from buckling without putting cross-bracings all the way through the middle? (stuff belongs in the middle).