A significant portion of space weather model research and development in the past two decades has been done as part of the Geospace Environmental Model (GEM) program of the National Science Foundation. The two major modeling centers are the Center for Space Environment Modeling (CSEM)[56] and the Center for Integrated Space weather Modeling (CISM).[57] The Community Coordinated Modeling Center[58] (CCMC) at the NASA Goddard Space Flight Center is a facility for coordinating the development and testing of research models, for improving and preparing models for use in space weather prediction and application.[59]