This thesis developed a linear shaped charge (LSC) separation mechanism capable of severing the interstage skin for first stage separation of the Ares I launch vehicle. The derived LSC design solution was found using available data on Explosive Technology’s Jetcord LSC and from National Aeronautics and Space Administration (NASA) Marshall Space Flight Center’s (MSFC) desired characteristics. Mechanism components are designed after Minuteman III’s separation mechanism for first stage separation and NASA MSFC’s desired characteristics. Mechanism severance is verified through the use of the numerical method capability smoothed particle hydrodynamics that the hydrocode Autodyn offers. Three simulations are conducted to determine feasibility: the first of only the LSC exploding, to numerically validate the explosion process; the second of the LSC penetrating the target, to numerically validate the penetration process and failure mechanisms; and the last of the entire mechanism, to obtain information about the explosion, penetration, failure, and debris generated.