Attitude Control of a Small Spacecraft in an Elliptical Orbit

A small research satellite is being developed by the Royal Aerospace Establishment, UK, for the purpose of in-orbit technology research. The satellite is planned for launch on an Ariane 4 mission into the severe environment of a geostationary transfer orbit in which it will remain. This paper addresses the challenges which have arisen in designing an attitude control system for a satellite in this unusual orbit. The paper includes discussion of how recovery from an initial tumbling state is to be performed why spin stabilization has been selected, how magnetorquers can be used to control the attitude and finally the effect of aerodynamic disturbance torques.