Approved for public release; distribution in unlimited. / The International Space Station (ISS) must be able to withstand the hypervelocity impacts of micrometeoroids and orbital debris that strike its many surfaces. In order to design and implement shielding which will prevent hull penetration or other operational losses, NASA must first model the orbital debris and micrometeoroid environment. Based upon this environment, special multi-stage shields called Whipple and Enhanced Stuffed Whipple Shields are developed and implemented to protect ISS surfaces. Ballistic limit curves that establish shield failure criteria are determined via ground testing. These curves are functions of material strength, shield spacing, projectile size, shape and density, as well as a number of other variables. The combination of debris model and ballistic limit equations allows NASA to model risk to ISS using a hydro-code called BUMPER. This thesis modifies and refines existing ballistic limit equations for U.S. Laboratory Module shields to account for the effects of projectile (debris/ micro-meteoroid) densities. Using these refined ballistic limit equations this thesis also examines alternative shielding materials and configurations to optimize shield design for minimum mass and maximum stopping potential, proposing alternate shield designs for future NASA ground testing. A final goal of this thesis is to provide the Department of Defense a background in satellite shield theory and design in order to improve protection against micrometeoroid and orbital debris impacts on future spacebased national systems. / Lieutenant, United States Navy