Abstract: Deployment and retrieval of a tethered satellite system is the basic issue of its application while the control scheme by varying the tension force of the tether has not been well investigated. In the article the tension force is considered as the control force and discretized in the time domain. The particle swarm optimization optimal algorithm is then used to search the optimal value fitting the optimal index in the feasible zone, thus obtaining the changing law of the control force. This control scheme can make the tethered satellite deploy to the equilibrium position in a short time under the optimal index of least swing and least time. Meanwhile, it is suitable to the retrieval. The simulation results shows this control law costs shorter time and less lateral swing compared with the control law based on varying the speed of deployment and retrieval. So it has some certain advantages.

Key words: tethered satellite , deployment, retrieval, particle swarm optimization, optimal index