Quick Answer: Aerospace refers to the technology and industry involved with the atmosphere and outer space collectively. Aerospace activity is very diverse, with a multitude of commercial, industrial, and military applications. Aerospace engineering consists of aeronautics and astronautics. Aerospace organizations research, design, manufacture, operate, maintain, and repair both aircraft and spacecraft. The border between space and the atmosphere has been proposed as 100 kilometres above the ground according to the physical explanation that the air density is too low for a lifting body to generate meaningful lift force without exceeding orbital velocity. This border has been called the Kármán line.