The Plasma Magnet Drive: A Simple, Cheap Drive for the Solar System and Beyond
The article says that since the thrust is always away from the Sun, it can't be used for inward journeys.  But if I'm thinking correctly, this isn't necessarily true.<p>If you're in a circular orbit, and run this for a while (short compared to orbital period), then turn it off, I think you'll be in an elliptical orbit with perihelion lower than your initial orbit.  If when you reach perihelion there happens to be a convenient planet with an atmosphere, you could aerobrake and either land or maybe continue in a circular orbit closer to the sun than your original orbit.