The distributed earth model orbiter simulation (DEMOS) three dimensional system at Johnson Space Center

Flight controllers at the NASA Mission Control Center in Houston have a new visualization tool to help them support the nation’s space program. The Distributed Earth Model Orbiter Simulation (DEMOS) system provides three dimensional realistic images of the shuttle as it orbits the Earth. The system displays the correct position and attitude of the spacecraft over the Earth’s surface. DEMOS also models the locations of the sun, the moon, the planets and the stars. Telemetry supplies the joint angles for the robot arm. Mission Flight controllers can monitor deployment of payloads when there is no live video. DEMOS provides a flexible mission analysis and real time support tool. It unifies the disciplines of celestial mechanics, three dimensional graphics and user interfaces. This paper describes the coordinate systems, the state vector propagation methods and the Attitude Maneuver Predictor (AMP) capabilities. The Attitude Maneuver Predictor simulates eigen-axis maneuvers. Flight controllers use this mode often for analysis of thermal constraints on payloads and on the orbiter.