Planetary exploration of Saturn moons Enceladus and Dione

Search for habitability in Outer Planets moons, requires presence of proper chemistry, water, and energy. Dissipation from tidal forces is major energy source in evolution of Icy moon systems, generically exhibiting a multi-layer structure, with outer solid (ice) and intermediate liquid layers, and solid (rocky) core. Saturn moon Enceladus has been found to eject plumes of water vapour and ice, and very recently, hydrogen molecules, a tentative sign of chemistry supporting microbial life. Purpose of the present work is a preliminary design of a minor electrodynamic tether mission to visit Enceladus. Free tether capture and maneuvering would take the S/C to a Saturn orbit with periapsis very close to the planet and apoapsis at Enceladus orbit, the S/C proved to be then in a 1:2 resonance with the moon, allowing parallel, conveniently slow flybys. Such mission could also involve visiting Dione, the 4 th largest Saturn moon, Enceladus and Dione being in a natural 1:2 Laplace resonance; it was recently brought to light that Dione exhibits multiple, parallel color lines, hundred kilometers long. •Operation as natural thermodynamic process.•Free propulsion-and-power system.•Efficient S/C capture due to large dipole offset.•Allowe a detailed visit to moon Enceladus.