Essential Spaceflight Dynamics and Magnetospherics Unperturbed Orbital Motion. Two Body Problem Qualitative Analysis of the Properties of Orbits Perturbed Motion Gravispheres Equations of Motion in Terms of Osculating Elements Braking of a SC in the Earth’s Atmosphere Terrestrial Nonsphericity and SC Motion SC Motion in the Field of Two Attracting Centers Elements of SC Manoeuvring Theory Interplanetary Trajectory Corrections Rendezvous Manoeuvring Gravity Assist Manoeuvre About Orbit Determination Using Measured Data to Attitude Control SC Affected by a Gravity Gradient Torque SC Motion in a Circular Orbit SC Motion in an Elliptical Orbit A Spinning Axisymmetric SC in Circular Orbit Equilibrium of a Gyrostat SC Motion Affected by an Aerodynamic Torque SC Motion in the Geomagnetic Field Motion of a SC under Damping. Essential Spaceflight Dynamics and Magnetospherics describes in the first instance some of the key aspects of celestial mechanics and spaceflight dynamics. It begins with classical two and three body problems illustrative of the aesthetic aspects of applying analytical methods of investigation to celestial mechanics. Then osculating orbital elements are introduced as well as analysis techniques sufficient to evaluate the influence of various disturbing forces on spacecraft. Next a theory of manoeuvres is outlined and the methodology of making interplanetary trajectory corrections. Ideas involving various approaches to orbital element determinations using measured data are also considered. The forces applied to a spacecraft can result in the development of torques that influence attitude motion and the effects of the most important of these are described in terms of equilibrium positions periodic motions steady state and transient motions. Also considered is the problem of attitude control of a spacecraft using active and or passive methods of orientation and stabilization. In addition a more advanced treatment of the development of attitude control systems is provided.