The Virtual Test Bed (VTB) is a distributed simulation environment for spaceport modeling. Using the High-Level Architecture (HLA) and integration frameworks based on software agents and the eXtensible Modeling Language (XML), this environment presents the integration process and implementation of several models of the operations taking place at a National Space and Aeronautics Administration (NASA) spaceport, before, during and after a Space Shuttle launch. Having a distributed environment is a needed feature of the simulation system due to the nature of the models since the operations modeled can in many instances be based at different geographic locations. The following operations are modeled and integrated: weather operations, range operations, launch probability operations, control room operations, and space shuttle model hardware processes and operations.
