The major weakness of a vacuum airship is that a breach of the pressure hull will compromise the vacuum and thus the buoyancy. So any truly useful solution will

The major weakness of a vacuum airship is that a breach of the pressure hull will compromise the vacuum and thus the buoyancy. So any truly useful solution will require a number of independent vacuum cells. The strongest shape made of compressive members is a tetrahedron, if surfaced with an impermeable and inelastic membrane an evacuated aerostat could end up looking like http://www.theatlantic.com/video/archive/2012/01/a-gorgeous-floating-crystal-inspired-by-alexander-graham-bells-kites/251224/ http://www.theatlantic.com/video/archive/2012/01/a-gorgeous-...