Engineers use technical specifications in order to design what they need to make. The rocket engine we give you is the 1/2A3-4T. For this camp, you only need to care about the length and diameter. The other things would matter for an engineer or physicist to be able to predict its performance.
https://www.apogeerockets.com/Rocket_Motors/Estes_Motors/13mm_Motors/Estes_13mm_1_2A3-4T_4-pack |