Rocket engines seem to be about flames and noise and pressure, not 'throwing things.' Let's look at a few examples to get a better picture of reality: This concept of 'throwing mass and benefiting from the reaction' can be hard to grasp at first, because that does not seem to be what is happening. The basic principle driving a rocket engine is the famous Newtonian principle that 'to every action there is an equal and opposite reaction.' A rocket engine is throwing mass in one direction and benefiting from the reaction that occurs in the other direction as a result. Rocket engines are fundamentally different. A steam engine is used to do the same thing, as is a steam turbine and most gas turbines. An electric motor produces rotational energy to drive a fan or spin a disk. For example, a reciprocating gasoline engine in a car produces rotational energy to drive the wheels. When most people think about motors or engines, they think about rotation.

In this article, we will look at rocket engines to understand how they work, as well as to understand some of the complexity surrounding them. On the other hand, rocket engines (and their fuel systems) are so complicated that only three countries have actually ever put people in orbit. Rocket engines are, on the one hand, so simple that you can build and fly your own model rockets very inexpensively (see the links on the last page of the article for details).

Space engine game problems