Nonlinear dynamic modeling and simulation of an atmospheric re-entry spacecraft

This paper discusses the dynamic modeling and simulation techniques for the X-38 re-entry spacecraft, a prototype crew return vehicle (CRV) for the in ternational space station (ISS). A general simulator for atmospheric re-ent ry dynamics (GESARED) was developed in the Matlab/Simulink environment. The 6 degree-of-freedom re-entry flight dynamics were modeled to achieve minim um restrictions and singularities. Quaternion representation of vehicle att itude was used to avoid computational singularities in angular kinematic mo del equations. The Earth's atmosphere, Earth's shape and gravitational pote ntial were modeled appropriately. The vehicle's aerodynamic characteristics , navigation sensors, and the actuator dynamics were also modeled and imple mented. Several numerical simulation tests and analyses were conducted to e valuate the performance of the model equations and the simulator. (C) 2001 Editions scientifiques et medicales Elsevier SAS.