In both science fiction and the daily news, we are bombarded with talk about various objects in orbit around the Earth, the Sun, other Planets, other stars, and on and on. But, how many of us have more than just glimmer of a clue as to what this means? What does it take to get into and out of orbit? And, once you are in orbit, what is required to move around to link up (or avoid) other objects in orbit? This is actually quite a bit of ground to cover so I’m going to split it into a series of articles.

To begin, we must first get an idea of what it means to be in orbit — which means that we need to have a little knowledge about gravity. To put it in simple terms: gravity is a force that pulls smaller masses towards larger masses (the smaller…