What are rockets like?

Seen up close, rockets are surprising for how little machine and how much tank there is to them. Most of their length is made up of cylindrical fuel and oxidizer tanks, separated by bulkheads and pressurized so the engines receive propellant without interruption. At the base sit the combustion chambers and nozzles, the only part that actually "pushes." The rest is lightweight structure: aluminum or carbon-fiber walls just a few millimeters thick, reinforced on the inside, designed to withstand enormous loads with minimal weight.

Almost all orbital launchers have two or three stacked stages. The first, the largest and most powerful, is jettisoned after a few minutes so it doesn't drag along dead weight; the second, smaller stage finishes the acceleration up to the 7.8 km/s needed for low Earth orbit. At the top sits the payload, protected by the fairing, an aerodynamic cover that opens and separates once there's no appreciable atmosphere left. Some vehicles add strap-on boosters, solid or liquid, for extra thrust at liftoff.

Proportions vary more than they might seem. A light launcher like Electron measures about 18 m; Falcon 9 reaches 70 m; Saturn V and Starship exceed 110 m. The slenderness comes down to aerodynamics: the narrower the vehicle, the less drag in the dense atmosphere. Solid rockets tend to be shorter and thicker; cryogenic ones, which carry low-density hydrogen, need much larger tanks for the same energy. And since 2015, many first stages have included legs and grid fins for returning and landing.