The ECS Earth Science Data Model organizes and describes the metadata for the Earth Observation System Data and Information Core System (ECS), and is useful to designers, developers, scientists and managers. The Data Model includes diagrams that graphically illustrate the relationships between classes and the attribute specifications. The relationships and information among data objects are described as they are understood and utilized within the Earth Science Community. It is represented as a practical means of assuring the consistency of data requirements across subsystems, and supporting the data standardization necessary for total system interoperability within a heterogeneous open systems environment.