From https://www.o-boot.com/en/faq/ https://www.o-boot.com/en/faq/ 8<-----------------------snip 6) Have you done structural calculations on the vacuum ballon

From https://www.o-boot.com/en/faq/ https://www.o-boot.com/en/faq/ 8<-----------------------snip 6) Have you done structural calculations on the vacuum ballon yet? What material can be strong enough to withstand air pressure and light enough to rise in flight? There are two models: a basic model and an evolution model. The first one, on which a degree research was done at the Polytechnic of Turin, is a sandwich with ceramic skins and foam in between. This model is lighter than air (obviously if emptied of inner air) and holds an external pressure (with zero internal pressure) up to 1.7 atm. The second model should withstand a similar external pressure but be lighter and easier to build. If you want, you leave us your email, and we send you the research thesis that was made on the first model, with all the structural calculations. Unfortunately, all information regarding the second model is confidential. 8<-----------------------snip Fingers crossed for December 13th!