1. The Earth's atmosphere and outer space: Aerospace is the air surrounding the Earth and the universe beyond it.
2. Relating to the design, manufacture, and flight of vehicles or missiles that fly in and beyond the Earth's atmosphere: Aerospace is the company dealing with aircraft, missiles, spacecraft, rockets, and satellites.

The main branch of engineering pertaining to the design and construction of aircraft and space vehicles: Aerospace engineering is also concerned with power units, with the special problems of flight in both the Earth's atmosphere and in space, such as in the flight of air vehicles and the launching, guidance, and control of missiles, the Earth satellites, and space vehicles and probes.