Magnetic Sail

The magnetic sail, or magsail is a concept which propels spacecraft by using the magnetic field generated by a loop of superconducting cable to deflect interplanetary or interstellar plasma winds. Assuming high temperature superconductors with the same current/mass ratio as existing low temperature superconductors, a magsail sailing on the solar wind at a radius of one AU can attain accelerations on the order of 0.01 m/s2, much greater than that available from a conventional solar lightsail. A net tangential force, or lift can also be generated. Using these forces, a magsail can transfer payloads to and from any two circular orbits in the solar system in a flight time slightly larger than the Hohmann ballistic transfer time without the expenditure of propellant. A magsail operating within the magnetosphere could interact with the Earth's magnetic poles to generate a series of perigee kicks to drive a payload of several times the magsail's e mass to interplanetary space in times scales of a few months. Magsails can also be made to interact with planetary ionospheres to lower orbits. Magsails could be used to create drag against the interstellar medium to decelerate ultrafast interstellar spacecraft, thereby enabling flights to the stars.