Mathematical Problems in Engineering
Volume 2009 (2009), Article ID 242396, 18 pages
Research Article

Spin-Stabilized Spacecrafts: Analytical Attitude Propagation Using Magnetic Torques

1Space Mechanic and Control Division, National Institute for Space Research (INPE), Sao Paulo, São José dos Campos 12227-010, Brazil
2Department of Mathematics, Group of Orbital Dynamics and Planetology, Sao Paulo State University (UNESP), Sao Paulo, Guaratinguetá 12516-410, Brazil

Received 28 July 2009; Accepted 4 November 2009

Academic Editor: Antonio Prado

Copyright © 2009 Roberta Veloso Garcia et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


An analytical approach for spin-stabilized satellites attitude propagation is presented, considering the influence of the residual magnetic torque and eddy currents torque. It is assumed two approaches to examine the influence of external torques acting during the motion of the satellite, with the Earth's magnetic field described by the quadripole model. In the first approach is included only the residual magnetic torque in the motion equations, with the satellites in circular or elliptical orbit. In the second approach only the eddy currents torque is analyzed, with the satellite in circular orbit. The inclusion of these torques on the dynamic equations of spin stabilized satellites yields the conditions to derive an analytical solution. The solutions show that residual torque does not affect the spin velocity magnitude, contributing only for the precession and the drift of the spacecraft's spin axis and the eddy currents torque causes an exponential decay of the angular velocity magnitude. Numerical simulations performed with data of the Brazilian Satellites (SCD1 and SCD2) show the period that analytical solution can be used to the attitude propagation, within the dispersion range of the attitude determination system performance of Satellite Control Center of Brazil National Research Institute.