Development Of The Simulation Software Platform For Satellite Orbit And Attitude Dynamics

This paper presents the design and implementation of the simulation software platform for orbit and attitude of satellite for the simulation of formation flying and the test of the on board attitude control programs. The software can demonstrate both orbit and attitude motion in the phases of launch, telemetry & telecommand and application of satellites by using animation technique.The test of on board programs must be done before launch. To simulate the real running condition of the program on board, the flight simulation software simulates space environment and sends date to the program. The software includes orbit and attitude calculators, simulators of space environments and telemetry & telecommand, and flying animations. All of above, except generationg telemetry & telecommand data configrations, are similar for every satellite. So it is necessary to design flight simulation software platform,which could test any on board program.Firstly, this paper presents the coordinates and time system for discribing satellite motion, and then gives the models of orbit and attitude and satellite relative motion, considered the J2 perturbation. Accroding the models, design idea and development setting are put forward. Combing the spacecraft orbit, attitude dynamics with computer graphics, the satellite simulation software based on 3D real-time display technique is developed. There are six functional modules: data management and analysis, orbit and attitude simulation, space environment simulation, ground station simulation, data communication and real-time animation. Upon the functional module, software's running process, data structure, and error handling are designed."SatelliteStudio", the simulation software for orbit and attitude ofsatellite, designed on the Microsoft Windows 2000 platform, by using VC 6. Directx3D and Socket technology are used for implementing 3D animation and data communication. "SatelliteStudio", with a friendly user interface, is a simulation and analysis tool for orbit, attitude and formation flying. Two independent processes－flight simulation process and demonstration process－are runed at the same time. The former includes data management and analysis, orbit and attitude simulation, space environment simulation, data communication and real-time animation. The later simulates data communication between ground station and the on broad program.