This paper presents a method for obtaining the attitude changes experienced bya spinning satellite under torques induced by free-molecular flow. The resultsare relevant for objects in elliptical Earth orbits with perigees below about 600km. In particular, this includes satellites and rocket bodies in geostationarytransfer orbits. First, a few fundamental aspects of free-molecular flow interactionswith satellite surfaces are presented, e.g. the momentum exchanges originatingfrom Maxwell-Boltzmann's kinetic gas theory. Expressions for theforces and torques acting on typical spinning satellite configurations are given.The average change in the attitude pointing over a spin revolution is establishedby integrating the torque vector over the perigee region. The integral isevaluated in the form of an asymptotic series expansion. Its leading term is ananalytical expression in terms of the orbital elements, the angle between velocityvector and spin-axis, the air density and scale height values, the satellite'sgeometrical parameters, and the coefficients modeling the molecular flow andsatellite surface interactions.
展开▼
