"Flying machines as these were of old, and are made even in our day." -- Roger Bacon, natural philosopher, 1260
Flight is tens of thousands if not millions or billions of years old.
Prehistoric kite art has been found in a cave on Muna Island off the coast of Sulawese.
But 21st century science is only now realizing and utilizing this prehistoric technology.
Cooney, M., Football Sized Kite Powers Latest Heavy Freight Ship, Network World, Nov 2007
A kite the size of a football field will provide most of the power for a German heavy freight ship set to launch in December.
The Beluga shipping company that owns the 460-foot Beluga said it expects the kites to decrease fuel consumption by up to 50% in optimal cases as well as a cutback of the emission of greenhouse [sic] gases on sea by 10 to 20%. Interestingly, the ship will be hauling windmills from Esbjerg, Denmark to Houston, Texas.
The company that makes the kite for the German transport, SkySails, has made kites for large yachts but is targeting commercial ships with new, larger kites. And it has the ambitious goal of equipping 1,500 ships with kites by 2015.
The SkySails system consists of a towing kite with rope, a launch and recovery system and a control system for the whole operation. The control system acts like the autopitot systems on an aircraft, the company says. Autopilot software sends and receives data about the sail etc to make sure the sail is set at its optimal position.
The company also says it provides an optional weather routing system so that ships can sail into optimal wind conditions.The kites typically fly at about 1,000 feet above sea level, thereby tapping winds that can be almost 50% stronger than at the surface.
Skysail isn't the only company pioneering kite technology. A US company, KiteShip, in Martinez, Calif., has been building ultra-large kites mostly for the private yachting sector, with plans to expand into cargo and cruise vessels.