Editing Solar sail (section)

== Alternatives ==
=== Electric solar wind ===
{{main | Electric sail }}

[[Pekka Janhunen]] from [[Finnish Meteorological Institute|FMI]] has  proposed a type of solar sail called the [[electric solar wind sail]].<ref>{{cite web|url=http://www.space.fmi.fi/~pjanhune/Esail/|title=Solar Sails Could Send Spacecraft 'Sailing' Through Space|author=NASA}}</ref> Mechanically it has little in common with the traditional solar sail design. The sails are replaced with straightened conducting tethers (wires) placed [[radius|radially]] around the host ship. The wires are electrically charged to create an [[electric field]] around the wires. The electric field extends a few tens of metres into the plasma of the surrounding solar wind. The solar electrons are reflected by the electric field (like the photons on a traditional solar sail). The radius of the sail is from the electric field rather than the actual wire itself, making the sail lighter. The craft can also be steered by regulating the electric charge of the wires. A practical electric sail would have 50–100 straightened wires with a length of about 20&nbsp;km each.<ref>{{cite web |access-date= Jan 2, 2022 | url=https://www.electric-sailing.fi/ | title=Electric Solar Wind Sail (E-sail)}}</ref>

Electric solar wind sails can adjust their electrostatic fields and sail attitudes.

=== Magnetic ===
{{main | Magnetic sail }}

A [[magnetic sail]] would also employ the solar wind. However, the magnetic field deflects the electrically charged particles in the wind. It uses wire loops, and runs a static current through them instead of applying a static voltage.<ref>{{cite web|url=http://www.niac.usra.edu/files/library/meetings/fellows/nov99/320Zubrin.pdf |title=Fellows meeting |date=1999 |website=www.niac.usra.edu/files }}</ref>

All these designs maneuver, though the mechanisms are different.

Magnetic sails bend the path of the charged protons that are in the [[solar wind]]. By changing the sails' attitudes, and the size of the magnetic fields, they can change the amount and direction of the thrust.