[FPSPACE] Electric Sail Rides the Solar Wind

[LARRY KLAES]

Electric Sail Rides the Solar Wind

A Finnish team has introduced a new wrinkle on the solar sail idea. Or more 
specifically, on the general principles of the magnetic sail, which would 
tap the propulsive power of the solar wind to push a ’sail’ created as a 
field around the spacecraft itself. The so-called ‘electric sail’ would use 
fifty to one hundred 20-kilometer long charged tethers, their voltage 
maintained by a solar-powered electron gun aboard the vehicle. We’re talking 
about tethers made of wires that are thinner than a human hair, thin enough 
that each can be wound into a small reel.

But unwind the tethers and you get interesting results. The electric field 
of each wire now extends tens of meters into the solar wind flow. A single 
tether yields the equivalent effective area of a sail roughly a square 
kilometer in size. You can see the promise of deploying multiple tethers to 
reach high velocities. What’s more, this sail allows the spacecraft to 
‘tack’ towards the Sun as well as sailing outward from it.

Full article here, including links to the technical paper and animations:

http://www.centauri-dreams.org/?p=1144