If you can imagine thousands of years ago, early humans walked on the earth and probably looked toward the skies, watching birds soar effortlessly and thinking, "... if only I could fly!" Aviation as we know it today is a mature but very young technology as time goes. Considering that the 100th anniversary of flight was celebrated just a few years ago in 2003, millions of people fly from city to city or from nation to nation and across the oceans and around the world effortlessly and economically. Additionally, we have space travel that has taken us beyond our atmosphere to the moon and Mars and beyond.
As we look at aviation, we generally think in terms of airlines and passenger travel. However, there are many other applications of aircraft beyond carrying passengers. Aircraft are used for transporting packaged goods, mail, foods, medical supplies, and other materials. But there are other applications that aircraft are used for, such as observation, mapping, weather, and reconnaissance missions. Some aircraft are piloted, and others are remotely controlled and are called unmanned aerial vehicles or UAVs. Here we will focus on the highlights of unmanned aerial vehicles.
It is important to realize that the invention and development of flight and flying machines represent the accumulation of much knowledge by many people over many years. To put things into perspective, it was about the time of the Wright brothers' early flights in 1903 that we saw the introduction of the automobile, large scale use of trains, steam-powered ships, and the introduction of wireless radio technology. In other words, there was a revolution in technology--the way that we travel and communicate--right before our eyes!
During the early years of flight and flying, tinkerers, inventors, engineers, and scientists tried many different types of experimental designs and aircraft in attempts to fly. During the first part of the twentieth century there was significant interest in flying and flying machines. According to some, the early years of flight could be characterized as an art and science because there are many scientific laws and principles that govern flight, and flying was an "art" in the sense that the flyer needed to understand the aircraft. The Wright brothers, Orville and Wilbur, the owners of a successful bicycle shop in Dayton, Ohio, became interested in flying and flying machines in 1896 after reading about the death of Otto Lilienthal. Lilienthal was quite prominent in influencing the Wright brothers to pursue their interests in aviation. Accordingly, they were avid readers about the latest developments in flight and methodically taught themselves everything to know about flying at the time. Lilienthal was a significant player in the development of flight, as it was through his efforts that the perception of flight and flying was more than a pastime for fools and tinkerers. Although his designs had flaws, Lilienthal had an immense influence on aviation. His writings were translated and distributed worldwide, and the photographs that documented his flights visually proved that a human could launch himself into the air and stay aloft. He demonstrated the importance of identifying the principles that governed an experiment before proceeding, and his meticulous documentation of his research provided guidance for those who came after him.
The Wright brothers wrote to Octave Chanute and Samuel Langley at the Smithsonian Institution regarding developments in flight and flying. It is important to note that the interest in flight and flying was an international interest, as there were many people in Europe constructing flying machines and experimenting with the principles of flight. Several historical individuals were Leonardo Da Vinci, the inventor of the ornithopter; Daniel Bernoulli, a Swiss scientist noted for his discoveries of the mathematical relationship of fluids flowing along a surface such as an airfoil; Sir George Cayley, who realized that the propulsion system of an airplane should generate thrust, and the wings should be shaped so as to create lift. …