The use of electrodynamic tethers for propulsion and power generation is attractive for missions to the outer planets, which are traditionally handicapped by large propellant requirements, large times of flight, and a scarcity of power available. The proposed electrodynamic tether propulsion scheme is shown to be capable at reducing or eliminating these mission constraints. In this work, the orbital dynamics of a spacecraft using electrodynamic tether propulsion during the mission phases of capture, apojove pump-down and perijove pump-up in the Jovian system are investigated. The main result is the mapped design space involving mission duration, tether length and minimum perijove radius. Phase-free flyby sequences and bang-bang control laws are also included, which provide performance upper bounds for a given mission architecture. It is found to be advantageous to utilize in-bound only flybys of the Galilean moons during capture, and few, if any, out-bound only flybys during apojove pump-down. The electrodynamic tether system is also shown to be capable of lowering the spacecraft’s orbit to a Europa-Ganymede Hohmann orbit with a total flight time after entering Jupiter’s sphere of influence of just under two years. The benefits of leveraging solar third body perturbations, ballistic flyby tours, and adding a secondary propulsion system are also considered. / text

We present optimal solutions for a point-mass electrodynamic tether (EDT) performing phasing and orbit-raising maneuvers. An EDT is a conductive tether on the order of 20 km in length and uses a Lorentz force to provide propellantless thrust. We develop the optimal equations of motion using Pontryagin's Minimum Principle. We find numerical solutions using a global, stochastic optimization method called Adaptive Simulated Annealing. The method uses Markov chains and the system's cost function to narrow down the search space. Newton's Method brings the error in the residual to below a specific tolerance. We compare the EDT solutions to similar constant-thrust solutions and investigate the patterns in the solution space. The EDT phasing maneuver has invariance properties similar to constant-thrust phasing maneuvers. Analyzing the solution space reveals that the EDT is faster at performing phasing maneuvers but slower at performing orbit-raising maneuvers than constant-thrust spacecraft. Also several bifurcation lines occur in the solution spaces for all maneuvers studied. / Master of Science