In Subtopic X11.01, NASA has identified the need to develop advanced radiation-shielding materials and systems to protect humans from the hazards of space radiation during NASA missions. The radiation components of interest include protons, alpha particles and heavy ions from galactic cosmic rays, protons and other ions from solar particle events, and high energy electrons and neutrons. International Scientific Technologies, Inc., in conjunction with the College of William and Mary, proposes to raise the technology readiness level of selected polymeric radiation-shielding materials through participation in the Materials on the International Space Station Experiment program, named MISSE-X. Phase I Technical Objectives will include assessment of the radiation environment in the orbital path of the International Space Station, selection of radiation-shielding polymeric materials for long-duration experiments in space, specification of active detectors/dosimeters for measurements of radiation in space, and design and optimization of an experiment package for inclusion on the MISSE-X platform for space-radiation environmental study. The anticipated result of the Phase I program is a proof-of-feasibility that will show the path toward a Phase II technology demonstration on board the International Space Station.