Spin Decay, Spin-Precession Damping, and Spin-Axis Drift of the Telstar Satellite

Abstract

Dynamical problems of the spin-stabilized Telstar satellite, characterized by spin decay, spin-precession damping, and spin-axis drift, are analyzed in this paper. Both the eddy-current torques and the magnetic torques, which cause the above three phenomena, are evaluated. By extrapolation from the observed data, the characteristic time of the nearly exponential spin decay of the satellite is estimated to be about 330 days. A linear analysis of the precession damper is made, and the results are compared with experiments, showing that the satellite precession angle will diminish by a factor of e in a maximum time of 30 minutes. A qualitative description is given to illustrate the fundamental mechanism of spin-axis drift. Results of these analyses can be applied to any spin-stabilized satellite