Thiokol Propulsion, a unit of Cordant Technologies, is developing all-composite compressed natural gas-CNG-tanks for automotive use. The tanks are constructed of two or more individual pressure cells made with filament-wound carbon fiber composites. The individual cells have flat interior sides so as to maximize usable storage volume. They are designed for service pressures of 3,600 psi and ultimate burst requirements of 8,100 psi. Thiokol expects the vessels to be certified next year under the natural gas vehicle industry's NGV2 protocol. The CNG tank initiative is one of several where Thiokol is applying advanced materials expertise to non-aerospace markets, one other being composites with minimum longterm storage requirements. Britain's Lucas Aerospace was a supplier of metal-lined CNG tanks for some of Ford natural gas vehicles but left the business earlier this year.