#aerospace definition

• Aeronaut — A specialized or authorized person who navigates through the atmosphere using an aerostat, an airship, or a balloon; a pilot or member of the flight crew operating an aircraft lighter than air. In a historical sense, the term designates the pioneers of atmospheric flights who paved the way for airspace exploration.
• Aeropause — A transition zone or upper region of Earth's atmosphere, located beyond the dense layers, where the air density becomes so low that it can no longer provide lift for conventional aircraft or support sound wave propagation. This structural threshold marks the functional limit of classical aviation and the beginning of upper aerospace, where flight is governed exclusively by orbital mechanics.