How to Pick the Optimal Rocket Engine
From ion thrusters to staged combustion engines
Rocket engines come in much larger variations than car or airplane engines. But why is there so much variation and not more standardization? Why not use the same type of engine in different sizes depending on how big the rocket is?
The key driver of the great variation of rocket engine design is the conflicting tradeoff between power and efficiency. Very powerful engines tend to be inefficient, while very efficient engines tend to be weak. A powerful rocket engine has high thrust. Thrust is usually measured in Newtons.
1 Newton (N) is the force that causes an object of mass 1 kilogram (kg) to increase its velocity by 1 meter per second every second (m/s²).
As an example, gravity on earth exerts a force of 9.8 Newtons on an object of mass 1 kg. An object of 10 kg would experience a gravitational pull of 98 Newtons.
The measure of efficiency of a rocket engine is a little harder to grasp. When talking about cars, we will relate engine…
