A sleeping cylindrical giant points upward from a large concrete slab. Next to it stands the launch tower, pumping fuel into the cylinder and ferrying technicians up and down the length of its body. The voice of the launch controller intones: "T minus one second . . . ignition." The giant roars up into the sky, impaled on a pillar of fire and smoke.

Flowery metaphors aside, this is an ordinary, everyday rocket launch. However, the steps leading up to that moment are anything but ordinary. Understanding these steps requires a basic knowledge of how rockets are built.

To escape Earth's gravity, rockets utilize a technique called staging. A staged rocket consists of two or more cylindrical rocket bodies stacked one on top of another. Each stage has its own propellant, tanks, engines, and instrumentation. The first stage does the heavy lifting of getting the vehicle off the ground...