Thermal force effects on slowly rotating, spherical artificial satellites .2. Earth infrared heating

The theory developed in Farinella and Vokrouhlicky (Planet. Space Sci. 44, 1551-1561, 1996) is applied for the thermal force effects affecting the motion of LAGEOS-type artificial satellites to the specific case of the so-called Yarkovsky-Rubincam effect, due to anisotropic heating of the satellite's surface by the Earth's infrared radiation. This theory allows the usual assumption of a fast rotational motion of the satellite to be removed, so as to allow for a misalignment between the direction of the thermal force and the spin axis. When applied to the LAGEOS satellite, which has been strongly despun by magnetic torques since its launch in 1976, the theory shows that in the next decade the orbital perturbations associated with the Yarkovsky-Rubincam effect will become much different than those predicted by the simple rapid-rotation approach. This is the case both for the drag-like effect causing a semimajor axis decay, and for the inclination changes. (C) 1997 Elsevier Science Ltd.