Aerospace Engineers develop aircraft, spacecraft, satellites and misssiles. They may develop new technologies for use in aviation, defense systems, and spacecraft. There are two types of aerospace engineering: aeronautical and astronautical. Aeronautical engineers work with aircraft. They study the theory, technology, and practice of flight. Astronautical engineers work with the science and technology of spacecraft and how they perform inside and outside the earth's atmosphere. Both of these fields depend on the basic principles of physics.