Rocket Dynamics

In this section we will take a closer look at the rocket dynamics, and especially at satellite launchers. What forces act on the launchers, why and in which direction. Then we will discuss how one can do simple simulations of a small rocket launch. Finally, a case example of the Ariane 5 launch vehicle is presented.

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Figure 1: Serial staging (Source NASA)

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Figure 2: Ariane 5 on launch pad

Smaller rockets, from model rockets you can balance on a finger and rockets up to a few meters in length typically has only one motor, which is most often attached to the rest of the rocket during the launch. This is simple and inexpensive.

However, when you want to go to high altitudes, todays rocket motors is not efficient enough to go to high altitudes with only a single rocket motor stage.

While the hunt for a «single-stage to orbit» launch vehicle continues, today’s launch vehicles is multi-staged, meaning that the rocket consist of several stages, both in parallel and in serial configuration. The rocket detaches burned-out stages and continues without them to lower the overall weight.

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Figure 3: Parallel staging (Source NASA)

Ariane 5 consists of two solid boosters working in parallel with the first-stage core motors, and a smaller upper stage which is ignited after the first stage core separation. A scientific sounding rocket launched from Andøya Space Center typically has between two to four motor stages, all with solid state motors.

ESA has an excellent video of the Soyuz launch sequence, the same launcher as is used at the European launch site of Kourou in French Guiana:

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This article is a part of a pre-course program, used by NAROM in different courses, for example Fly a Rocket!