New electric solar sail concept

Interesting. [Link]

In a departure from the photon-powered solar sail, scientists and engineers have started to look into the properties of solar wind particles as a possible source of propulsion. The advantages of using solar wind particles are they a) are electrically charged, b) have high velocity (interplanetary scintillation observations have deduced velocities as high as 800 km/s, or 1.8 million miles per hour), and c) are abundant in interplanetary space throughout the solar system (particularly at solar maximum). So the new Finnish concept will take full advantage of this highly charged interplanetary medium. Using a fan of very long, electrically charged cables (stretching many kilometres from the central spacecraft), the similarly charged solar wind particles (mainly positively-charged protons) will hit the fan of positively-charged cables (generating a repulsive electric field), giving the cables a small proton-sized "kick", exchanging their momentum into spacecraft thrust. Cable charge is maintained by a solar-powered electron gun, using two conventional solar panels as an energy source. A radio-frequency "boost" will also be tested in the prototype model. Radio waves will cause electron heating, possibly enhancing the solar sail's thrust.