Two-bar model for free vibrations damping of space tethers by means of spring-dashpot devices

Abstract Present guidelines indicate the need to deorbit new satellites launched into low Earth orbit (LEO) within 25 years from their end of life. Our research task is to develop a new technology suitable to deorbit a satellite at the end of life with as small an impact as possible on the mass budget of the mission. An alternative to the traditional chemical rockets consists in using an electrodynamic tether that, through its interaction with the Earth ionosphere and magnetic field, can take advantage of Lorentz forces for deorbiting purposes. However, Lorentz forces produce a low and yet continuous injection of energy into the system that, in the long run, can bring the tether to instability. This paper addresses this issue through the analysis of the benefits provided by an elastic-viscous damping device installed at the attachment point of the tether to the spacecraft. The analysis carried out by means of linearization of dynamics equations and numerical simulations show that a well-tuned damper can efficiently absorb the kinetic energy from the tether thus providing system stability during deorbiting. @ CEAS 201