Hi, for a piece of coursework I'm doing I'm researching magnetic sails. I don't know how familiar everyone is with the idea. Its not like a solar sail rather a large loop of superconducting wire which creates a magnetic field and deflects the oncoming solar wind which imparts momentum into the spacecraft. I am trying however to do some calculations. Drawing a diagram of the magnetic field lines around the superconducting wire and using Flemmings left hand rule, i cannot actually figure out how it gets "pushed" along? Since as the force acting on the particle in the magnetic field is always at right angles, I'm guessing the particles follow curved trajectories and therefore have a decrease in the horizontal component of their velocity, therefore by conservation of momentum, the spacecraft should speed up... So at the moment I'm trying to do some rough calculations using F=BQVsintheta and biot savart law but I'm finding it hard to visualize. If you imagine a cross section of the loop of wire, at the top current flowing away, and at bottom current flowing towards. Am I on the right lines?

any help would be much appreciated =)

Mike