The goal of the proposed work is to provide the Air Force with a state-of-the-art model of the outer zone energetic charged particles, including data assimilation capabilities. The UCLA-developed Versatile Electron Radiation Belt (VERB) model will be optimized for various measurements obtained on various satellite orbits by different instruments. We will transfer VERB code to SSI, test and validate it. We will perform data assimilation using LEO, MEO, and GEO satellites, develop documentation, and adapt the codes to Air Force needs and requirements.