Fundamentals of Motion

After setting the stage by discussing the flight environment and the external forces originating from that, i.e., the ones due to gravity and the aerothermodynamical loading, these forces will now be linked to the motion of the vehicle. This chapter approaches the topic from a more fundamental point of view, whereas in the next chapter the physical mechanisms of re-entry flight will be discussed. The velocities of re-entry flight are usually not so high that classical mechanics can no longer describe the vehicle’s motion. Within this field of mechanics it is Newton’s Laws of Motion that lie at the root of it. Originally postulated for motion in an inertial frame the concept of reference frames becomes an important aspect.