Glossary of aerospace engineering

Wright flyer fragments STS-51-L

Glossary of Aerospace Engineering

Aerospace engineering is a field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Aeronautical engineering focuses on the theory, technology, and practice of flight within the Earth's atmosphere, while astronautical engineering focuses on the science and technology of spacecraft and launch vehicles. This glossary provides definitions and explanations of key terms, concepts, and components relevant to the field of aerospace engineering.

A

• Aerodynamics: The study of the properties of moving air, and especially of the interaction between the air and solid bodies moving through it.
• Aerospace: The branch of technology and industry concerned with both aviation and space flight.
• Aileron: A hinged flight control surface on the wing of an aircraft which controls roll.
• Altitude: The height of an object in relation to sea level or ground level.
• Attitude control: A mechanism or system used on spacecraft to control the orientation of the vehicle relative to the Earth, the stars, or another spacecraft.

B

• Bernoulli's principle: A principle that explains how the pressure of a fluid (liquid or gas) decreases at points where the speed of the fluid increases.

C

• Canard: A small forewing or horizontal stabilizer placed in front of the main wing of an aircraft to improve stability.
• Control surfaces: Surfaces which control the attitude of an aircraft or spacecraft, including ailerons, elevators, rudders, and spoilers.

D

• Drag: The force that opposes an aircraft's motion through the air.

E

• Elevator: A control surface on the tail of an aircraft which controls pitch.
• Engine: A machine designed to convert one form of energy into mechanical energy. In aerospace, engines such as jet engines and rocket engines are used.

F

• Flap: A hinged surface on the wing of an aircraft, used to increase lift or drag, depending on its setting.
• Flight envelope: The limits of speed, altitude, and angle of attack within which an aircraft can safely operate.

G

• G-force: A measure of acceleration felt as weight. It is especially important in determining the structural and human tolerances for aircraft and spacecraft.

H

• Hypersonic: Speeds greater than five times the speed of sound (Mach 5).

I

• Inertial navigation system (INS): A navigation aid that uses a computer, motion sensors, and rotation sensors to continuously calculate the position, orientation, and velocity of a moving object without the need for external references.

J

• Jet engine: A type of reaction engine that discharges a fast-moving jet of fluid to generate thrust in accordance with Newton's laws of motion.

L

• Lift: The force that directly opposes the weight of an airplane and holds the airplane in the air.

M

• Mach number: A dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound.

N

• Nose cone: The forwardmost section of a rocket, missile, or aircraft, designed to minimize aerodynamic drag.

O

• Orbit: The gravitationally curved trajectory of an object, such as the path of a planet around a star or a satellite around a planet.

P

• Propellant: A chemical substance used in the propulsion of rockets and other spacecraft, which is expelled in the form of a high-speed stream of gas to produce thrust.

R

• Rudder: A primary control surface used to steer an aircraft or spacecraft, typically located on the vertical stabilizer.

S

• Satellite: An artificial object which has been intentionally placed into orbit around a planet, including moons, planets, stars, and other celestial bodies.
• Supersonic: Speeds greater than the speed of sound (Mach 1).

T

• Thrust: The force which moves an aircraft through the air. It is generated by the aircraft's engines.

V

• Velocity: The speed of an object in a particular direction.

W

• Wing: A surface used on an aircraft to generate lift, allowing it to fly.