Though partially funded by NASA, it is still a private site. Therefore, before downloading any materials for use, you need to ask permission. In Aviation Leonardo da Vinci was known for his attempts to design a mechanical device using arms and legs which activated flapping wings through a system of pulleys and levers. Joseph and Etienne Montgolfier designed the first hot air balloon.
Hot air is lighter than the surrounding colder air and causes the balloon to rise.
Hot air ballooning was slightly dangerous because the brazier which maintained the supply of hot air in flight could also cause the fabric to catch fire. He realized man had held the key when flying a kite. The basic principles upon which modern aeronautics is founded were formulated by George Cayley. Cayley's vehicles were launched by ramp because the internal combustion engine had not yet been invented. The Wright Brothers made several short flights at Kitty Hawk, North Carolina on December 17, 1903.