Joefaust 05:15, 24 January 2007 (UTC)
The Rogallo flexible wing is a self-inflating system that was tested for the Gemini space capsule recovery.
Rogallo wing used by NASA for spacecraft landing research
On 1948, Francis Rogallo -a NASA engineer- and his wife Gertrude Rogallo, invented a self-inflating flexible wing or 'Rogallo wing'.[1] NASA considered Rogallo's flexible wing as an alternative recovery system for the Gemini space capsule and on the Paresev for possible use in other spacecraft landings, but the idea was dropped in 1964.
A rogallo wing is composed of two partial conic surfaces with both cones pointing forward. Slow rogallo wings have wide, shallow cones. Fast subsonic and supersonic rogallo wings have long, thin, narrow cones. The Rogallo wing is a simple and inexpensive flying wing with remarkable properties. It is most often seen in toy kites, but has been used construct parachutes, small aircrafts and hang gliders.
In 1960-62 American Barry Palmer foot-launched several versions of framed rogallo hang gliders to continue the recreational and sporting spirit of hang gliding. Palmer pre-dated by 6 or 7 years Bill Moyes' foot-launching of the modern rogallo-winged hang glider. Another key player in the development of the modern Rogallo type hang glider was Australian John Dickenson who in 1963 was shown a photo of Rogallo's fexible wing and set to build towed ski kite and a portable and controllable glider. Dickenson used Rogallo's wing as a base lifting wing and added at first a U-frame (later an A-frame control bar) to it; it was composed of a keel, leading edges, a cross-bar (as did the 1960 Parasev Paraglider Research Vehicles) and a fixed A-frame, making weight-shift his choice to control the glider after release from tow. Hang gliders had been with weight-shift control (as did other hang glider pilots for sixty-five or so years before). The flexible-sailed rogalloish-wing towed kite was first flown in public at the Grafton Jacaranda Festival in September of 1963 by Rod Fuller while towed behind a motorboat.
In 1967 Bill Moyes became the first to foot-launch a Dickenson wing (a Rogallo wing with an A-control-bar sub-assembly); this was a full 6 or 7 years after Barry Palmer was first to foot-launch and fly a Rogallo wing hang glider with a frame hanging the pilot below the wing. Moyes went on to develop his own line of kites and hang gliders; the data of N.A.S.A. reports on the rogallo wing were used throughout Australia in the late 60s by hang glider sail makers for Bill Moyes and Bill Bennett; those "two Bills" exported new refinements of the Rogallo-type hang glider throughout the world. Novelties by the Bill Moyes and his sons were added to the technical base that they saw in N.A.S.A.'s technical reports and the Dickenson improvements of 1963-1966 kites and hang gliders. The pioneering efforts by Barry Palmer, the talks by Frances Rogallo, the circulation of N.A.S.A. reports, the experiments of Jim Hobsen (related to the Lawrence Welk company in Santa Monica, CA), and many activities in light gliders and hang gliders in the Soaring Society of America underground community lead in part by Richard Miller already formed a vast momentum over many types of hang gliders and light gliders...which momentum combined with the sparks of the "two Bills" to form a boon in hang gliding in the USA. It was Jack Lambie, Richard Miller, and Joe Faust that spawned the National Geographic coverage and radiated an interest that dominantly sparked the modern hang gliding movement that respected and still respect tens to types of hang gliders; indeed, in one perspective, the sporting interest in the rogallo family of hang gliders wins in head-count participation, but there remains builders and flyers of biplane hang gliders, multi-plane hang gliders, paraglider hang gliders, bat-wing hang gliders, Lilienthal replica hang gliders, rigid-wing hang gliders, monoplane flying wing hybrid hang gliders, canard and tandem hang gliders, and more. Advanced materials will continue to allow development in all the different types of modern hang gliders.
A rogallo wing is not very efficient, but the design is forgiving, flexible, light and inexpensive. Variations work at most Reynolds numbers (almost all real fluids, including air, water, hydrogen, and carbon dioxide) from very low subsonic speeds (5 km/h in air) to very high supersonic speeds (as high as Mach 25 in air). Further, if constructed from heat-resistant materials with an appropriate engine, it can form the wing of a supersonic waverider.
One of the special properties of the rogallo wing is that it can be constructed from a flexible membrane (such as plastic film or sail-cloth), and a simple A-frame. Using plastic-film and struts permits very inexpensive rogallo-wings to serve as kites. Large rogallo wings can be made to fold or roll into compact packages (i.e. car-top carriers for hang-gliders). Man-rated rogallo wings usually add a vertical posts near the center to anchor guy wires. Guy wires are placed to make the A-frame more rigid, so the cross-bar of the A-frame will not buckle while maneuvering.
The simplest way to steer and control a rogallo wing is to change its pitch and roll.
Most man-rated rogallo wings change the pitch and roll by suspending the payload or engine on a pendulum beneath the wing, and then moving the pendulum to change the vehicle's center of gravity. On hang-gliders, this is traditionally done by rigidly mounting a guyed trapeze-like triangular bar under the wing, and suspending the pilot prone in a harness within the triangle. The pilot holds and moves the trapeze with his hands.
Kite-like rogallo wings control the pitch with a bridle that sets the wing's angle of attack. A bridle made of string is usually a loop reaching from the front to the end of the center strut of the A-frame. The user ties knots (usually a lark's head) in the bridle to set the angle of attack. Mass-produced rogallo kites use a bridle that's a triangle of plastic film, with one edge heat-sealed to the central strut.
Steerable rogallo kites usually have a pair of bridles setting a fixed pitch, and use two strings, one on each side of the kite, to change the roll.
Rogallo also developed a series of soft foil designs in the 60's which have been modified for traction kiting. These are double keel designs with conic wings and a multiple attachment bridle which can be used with either dual line or quad line controls. They have excellent pull, but suffer from a smaller window than more modern traction designs. Normally the #5 and #9 alternatives are used.
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