The sequel to the Hugo Award finalist "The Hot Equations," "Objects in Motion" covers the basics of orbital mechanics from a writer's perspective. It touches on transfer orbits, types of rockets, and travel times. The article examines common military SF tropes in light of current knowledge and a half-century of human space flight.

The article is in ePub format, which is suitable for most e-readers, Apple iOS devices, and Android devices. A PDF version is also included.