Aerospace is an industry that includes space flight and aviation. It looks at the processes and designs that make it possible for people to travel in the aircraft that flies in the earth's atmosphere and the surrounding airspace. If you've seen an airplane in flight, you've witnessed the result of the work of aerospace engineers who are referred to as aeronautic engineers. Aeronautics is the branch of aerospace that describes flying within the earth's atmosphere. If you've watched space flights, such as the Apollo missions, on TV or the internet, you've seen the results of aerospace engineers known as astronautic engineers. Astronautics refers to travel in the airspace outside the earth's atmosphere.