Abstract: Subject is rocket foam. This letters patent is for construction of a space craft from acrylonitrile foam polymer. The new art involves making a polymer sheet plasticized with sulfur dioxide gas. The plasticize sheet is drape formed and then heated to drive off the gas leaving a rigid foamed polymer shape. The sheet during plasticize step is given a thin adherent layer of sand mingled in acrylonitrile polymer powder. Thermal heating during rocket reentry orbit generates a skin layer of carbide. The carbide protects against flame temperature air, to prevent combustion of the underlying carbon foam structure. A variation is to make the acrylonitrile polymer as a latex paint and apply such paint to a screen form geometry.