From the beginning, the United States Air Force USAF defined aerospace as "an operationally indivisible medium consisting of the total expanse beyond the Earth's surface." . Aerospace now is a now a term used to encompass everything from aerodynamics to space.
History & Etymology
The term aerospace may first have been used during Air Force discussions with the Congress. 
Aerospace as a subject has been explored for centuries. In a Greek legend of Icarus and his father Daedalus, they built wings of feathers and wax to escape prison. Leonardo da Vinci, was one early scientist to study what is now aerospace.
Modern research in aerospace is based on the work of Europeans, and the American Samuel P. Langley (1834-1906), who was sponsored by the Smithsonian Institution. The modern age begins with the independent (unsponsored) research by the Wright brothers that led to the first powered flight at Kitty Hawk, North Carolina on December 17, 1903. After 1910 the center of research moved to Europe, but the U.S. created the National Advisory Committee for Aeronautics (NACA) in 1915; in 1958 it became National Aeronautics and Space Administration (NASA).
- AFP 11-1-4, Interim Aerospace Terminology Reference, 30 October 1959, 2-3.
- House, Missile Development and Space Sciences: Hearings before the Committee on Science and Astronautics, 86th Cong., 1st sess., February and March 1959, 76-77.
- see The National Advisory Committee for Aeronautics (NACA)