Spacecraft dynamics is the study of how spacecraft move and behave in space. It involves understanding the forces acting on a spacecraft, such as gravity, thrust, and drag, which influence its trajectory and orientation. Engineers use mathematical models to predict how a spacecraft will respond to these forces, ensuring it can reach its destination and perform its mission effectively. Key concepts in spacecraft dynamics include orbital mechanics, which deals with the motion of spacecraft around celestial bodies, and attitude control, which focuses on maintaining the correct orientation of the spacecraft. These principles are essential for successful missions, such as those conducted by NASA or SpaceX.