Dynamical simulation of tether in orbit deployment

Abstract

The paper is aimed at studying the peculiarities of dynamical behavior of tether in its deployment in low Earth orbit during YES2 experiment in Foton-M3 mission, and performing flight data analysis with account of these effects. The analysis in the first part of the paper uses as input a pre-provided tension profile for the mission (resulting from a simulation to be independently validated). With this input it then performs an open-loop simulation which explains the sensitivity to the initial parameters. For the actual flight design a feedback mechanism and algorithm was used in order to control the deployment speed along a nominal profile, minimizing sensitivity to conditions such as initial velocity and endmass value. The paper provides solutions accounting for final velocities of wave propagation in tether, which is especially important for such stages of the deployment as sharp changing of the velocity direction and intensive braking. Moreover the YES2 data is used to validate the theoretical derivations.