An in-line damper for tethers-in-space oscillations dissipation

The dynamical stability of tethered systems can be strongly affected by deployment strategies and environmental disturbances and consequently energy dissipation strategies are implemented to reduce oscillation amplitudes. Among the possible solutions for passive dissipation, in-line dampers consist in small mechanisms employing viscous-elastic devices or electromagnetic damping systems. In this work a CubeSat-mission-sized in-line damper is presented and the ground testing to verify its working principle is introduced. The mechanism is designed for a 500-m tape tether deployment mission but can be easily scaled to other operational configurations. The effectiveness of this solution is assessed through a campaign of numerical simulations, that are also employed to calculate the damper main design drivers. The ground tests of a scaled prototype confirm the numerical results and indicate that the in-line damper influences positively the dynamics of a deployment manoeuvre by reducing the peak tensile loads and the deviations from the nominal deployment profile.