Has anyone here heard about the "magnetic sail"? No, not a thin film like the usual solar sail designs, this uses a superconducting ring about a km or more in diameter. The dipole magnetic field of the superconductor interacts with the solar magnetic field to fly between planets. Tied to the ring by spider webs, in something like a bicycle wheel configuration, the central cabin can be moved around within the central area for varying angles of attack/directions of thrust. The magnetic field also is like earth's magnetosphere, protecting the cabin from deadly solar radiation. This concept has been around for about 20 years. It was initially thought of as an interstellar propulsion mechanism in conjunction with a hydrogen scoop to gather up interstellar H1/H2/H3 for on-board thermonuclear fusion-thrust. Then it was determined, from calculations, that it really works better as a DRAG, thus it would be ideal as a sail "tacking" within the solar wind for interplanetary trips, with no fuel requirements other than moving the cabin(c.g. of system)here or there for with the solar wind(moving outward)or against the solar wind(moving inward). All it would require is putting the su-co wire/ring in orbit, charging it up with juice...and away you go, riding FREE on the solar wind...and protected from radiation in the su-co mag field cocoon...