The How and Why of Rockets' Staging

When we talk about spaceflight — modern or vintage, manned or unmanned, orbital or deep space — launch vehicles all serve the same purpose: overcome gravity and get the payload off the Earth. Whatever the mission, it starts with a rocket launch. Even, because I can hear you asking about it, payloads that were launched from the payload bay of the space shuttle; that payload got to orbit via a shuttle launch. And because all rockets harness the same technology, they all share one common element. Whether they’re big or small, they all go through staging.