Dynamics of Multi-Tethered Satellite Formations

Tethers have been used in space for quite some time. However, the concept of a multi-tethered system has received less attention. This work investigates the dynamics of certain configurations of multi-tethered satellite formations in Low Earth Orbits.Certain simplifications have been made prior to the investigation of the problem; these include considering the satellites to be point-masses and the tethers to be massless and straight. Configurations termed hub-and-spoke and closed-hub-and-spoke are analyzed.The local motion is studied under two distinct specifications for the orbital motion of the system: first, prescribed motion of the system centre of mass and second, prescribed motion of the central body of the formation. Three-dimensional motion is studied for formations lying in the orbital plane and in the Earth-facing plane normal to the orbit, while given an initial spin rate in their nominal plane.Later, two satellite formations deployed along the local vertical are examined: a closed-hub-and-spoke configuration with its spin axis along the long axis of symmetry, which is found to be unstable, and a double-pyramid configuration, which is found to be stable.