To achieve flight, heavier-than-air objects like planes or rockets must conform to certain principles of aerodynamics. Aerodynamics is the study of the motion of air and its interaction with solid objects. An aerodynamics engineer tests aerospace designs, such as aircraft bodies and propulsion systems to ensure they meet all aerodynamic specifications and conform to the physical laws of aerodynamics. Your duties and responsibilities include designing mathematical models and simulations to test designs before firms construct prototypes or full products. You also work to improve the efficiency of existing designs.