The Rogallo wing is a flexible type of wing. In 1948, Francis Rogallo, a NASA engineer, and his wife Gertrude Rogallo, invented a self-inflating flexible wing they called the Parawing, also known after them as the "Rogallo Wing" and flexible wing. NASA considered Rogallo's flexible wing as an alternative recovery system for the Mercury and Gemini space capsules, and for possible use in other spacecraft landings, but the idea was dropped from Gemini in 1964 in favor of conventional parachutes.
NASA Paresev, a Rogallo flexible wing tested by NASA for spacecraft landing research.
Gemini Rogallo wing during tests at Edwards Air Force Base in August 1964.
Rogallo wing considered as a candidate recovery system for the Apollo spacecraft
Gertrude and Francis Rogallo's original patented flexible wing
A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is expressed as its lift-to-drag ratio. The lift a wing generates at a given speed and angle of attack can be one to two orders of magnitude greater than the total drag on the wing. A high lift-to-drag ratio requires a significantly smaller thrust to propel the wings through the air at sufficient lift.
Wing of a Eurasian magpie, which allows flight by the flapping of wings.
A swept wing KC-10 Extender (top) refuels a trapezoidal-wing F-22 Raptor.
Condensation in the low pressure region over the wing of an Airbus A340, passing through humid air.
The wing of a landing BMI Airbus A319-100. The slats at its leading edge and the flaps at its trailing edge are extended.