Hang gliders have been around since the the 1800's, though the concepts of flight were not fully understood then, and very few, if any successful flights were made. They began to be practically used around the 1950's as a branch off of American aerospace research. These first designs were known as parawings, and were developed by Francis and Gertrude Rogallo. Early gliders had wooden or bamboo frames and polythene sails, which is primitive when compared to the new materials used in today's gliders, which will be discussed in further detail later. These gliders intrigued people then just as they do today because the concept of free flight is often an exciting idea. Nearly everyone (except those with an intense fear of heights) have dreamed at one time or another of being able to soar above the earth. Hang gliding is about the closest we can come to free flight, no motor or source of thrust involved, only you and the open sky.