Experimental study on dynamics and control of tethered satellite systems with climber

Tethered satellite systems (TSSs) open up the possibility of alternative forms of transportation such as space elevators, which could conceivably replace conventional space transportation systems in the foreseeable future. A simplified dynamic model of a TSS with a single climber is used to evaluate the fundamental librational motion. An optimal acceleration climber transit control scheme is developed by solving a two-point boundary value problem (TPBVP) that minimizes the time integral of the square of the climber transit acceleration along the tether, along with placing constraints on the final tether angle, climber's position and velocity. The numerical simulations show that if penalties are introduced with regard to the tether angles at the terminal time, residual librations resulting from optimal acceleration climber transits are smaller than for the case of constant speed climber transits. Experiments are carried out to validate the derived optimal climber acceleration profile, using the ground-based experimental setup that emulates the tether librational motion.