Influence of the atmosphere rotation

on attitude motion of satellite

Elena K.Duarte

Universidade da Beira Interior, Covilhã, Portugal

Instituto Nacional de Engenharia e Tecnologia Industrial, Lisboa, Portugal

e-mail:elena.koroleva@ineti.pt

V.A.Sarychev

Keldysh Institute of Applied Mathematics, Moscow, Russia

Universidade da Beira Interior, Covilhã, Portugal

e-mail:sarychev@demnet.ubi.pt

The attitude motion of the satellite subjected to gravitational and aerodynamic torques was analysed. It was assumed that Earth and its surrounding atmosphere rotate with the same angular velocity, the effect of atmosphere on the satellite is reduced to the drag force applied to the center of pressure, directed against the velocity of the satellite's center of mass relative to the air; the influence of the atmospheric drag on the orbital motion of the satellite is not considered. The case most interesting for the practical applications was examined - a satellite moving on a circular orbit and the center of pressure is located on one of the principal central axes of inertia. It is known that there are from 8 to 24 equilibrium orientations for such satellites in orbital coordinate frame, when the effect of the rotation of the atmosphere is neglected. The rotational effect of the Earth's atmosphere to each equilibrium orientation was investigated by a method of small parameter. It was shown that the position of equilibrium of satellite transforms into the periodic solution. The obtained results show the influence of the Earth's atmosphere rotation on the accuracy of attitude determination of satellite with aerodynamic stabilization system.