Editing Kite control systems (section)

===Commercial transport propulsion ===
Ship-pulling kites run to hundreds of square meters of area and require a special attachment points, a launch and recovery system, and fly-by-wire controls.

The [[SkySails]] [[Marine propulsion|ship propulsion system]] consists of a large [[foil kite]], an [[electronics|electronic]] [[Control engineering|control]] system for the kite, and an automatic system to retract the kite.

The kite, while over ten times larger, bears similarities to the [[arc kite]]s used in [[kitesurfing]]. However, the kite is an inflatable rather than a ram-air kite.{{citation needed|date=April 2017}} Additionally, a control pod is used rather than direct tension on multiple kite control lines; only one line runs the full distance from kite to ship, with the bridle lines running from kite to control pod. Power to the pod is provided by cables embedded in the line; the same line also carries commands to the control pod from the ship.<ref name=cherubini_etal>[http://ac.els-cdn.com/S1364032115007005/1-s2.0-S1364032115007005-main.pdf?_tid=4919600e-0bc8-11e6-bf67-00000aab0f02&acdnat=1461686733_a8f25d0787b25f451227cb02ac6376f0 Airborne Wind Energy Systems, a review of the technologies], A. cherubini, A. Papini, R. Vertechy, M.Fontana, Renewable and Sustainable Energy Reviews, 2015</ref>

The kite is launched and recovered by an animated mast or arm, which grips the kite by its leading edge. The mast also inflates and deflates the kite. When not in use, mast and deflated kite fold away.<ref name=cherubini_etal/>