Rocket science

Earth is the cradle of mankind, but man cannot live in the cradle forever — Konstantin Tsiolkovsky

5...4...3...2...1...[word removed in accordance with Citizendium family-friendliness policy — Reported to be the way the children of rocket scientists learned to count

Rocket science is an everyday term for astronautics, or astronautical engineering, the branch of engineering that deals with vehicles that travel in whole or in part through outer space. It is compared and contrasted with aeronautics, the field that covers vehicles travelling within the Earth's atmosphere. There are naturally overlapping areas within the two disciplines, so the modern tendency is to combine the two as aerospace engineering.

The term is also used when speaking of a relatively easy task being made difficult through opposition or incompetence. "This isn't rocket science, folks!"

Rocket scientist describes an aero/astro engineer. It is also used admiringly to refer to any extraordinarily intelligent person, or sarcastically to describe someone who has done something stupid.

Confusion in the actual term

"Rocket", per se, is either a relatively simple military device, firework, etc.; see unguided rocket, and multiple rocket launcher for some of the more lethal aspects. Indeed, see counter-rocket, artillery and mortar (C-RAM) for means of defending against certain of the military systems.

In more complex space launch vehicles (SLV) and in many, but not all, guided missiles, the rocket motor is a propulsion subsystem. Many SLVs and missiles have multiple rockets, which variously may be clustered into groups firing in parallel, rocket systems that fire in series or stages (i.e., step rocket), and various hybrids of "booster" and "sustainer" (e.g., Atlas (missile).