NASA - National Aeronautics and Space Administration

To provide additional thrust for the Ares I rocket, NASA engineers have designed a new 12-fin forward casting core. The 12-fin core is created by pouring propellant into an insulated and lined segment containing grain core tooling. The propellant mold is then inserted in to the solid rocket motor (SRM) casing. This creates open space in the center of the solid rocket which allows surface area for the propellant to burn.

Image credit: NASA

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