Book excerpt: Some theoreticians contemplate and formulate the physics of tachyons, which are hypothetical particles, that would always travel faster than light but which could never slow down to the speed of light just as they anticipate sublight speed massive particles never being able to achieve light speed. So my theoretical work on the physics and kinematics of light-speed massive systems sets me apart from general trends in the theoretical field of relativistic astronautics. This book is a continuation of how and why we may be able to, at some future time, travel at the speed of light.