Solid Propellant Rocket:

They are a type of rockets where the elements of combustion (fuel and comburent) are condensed in a solid geometric shape called “grain”. They are a type of rockets in which both the fuel and the comburent are in solid form.

Normally, in ordinary engines, the fuel and oxidant, or oxidizer, are in liquid form in separate tanks, where they are then pumped into the combustion chamber for reaction. In this type of rockets, however, we find the fuel and oxidant in solid form, forming a hollow cylinder called “grain”.

This “grain” of hollow cylindrical shape, whose internal chamber is called vein, is where combustion occurs. The shape of that internal surface is determinant for the push-time profile of the gases produced Combustion occurs on the inner surface of the “grain”, and the shape of this surface has an influence on the push-time relationship with which they will come out the gases produced in the reaction [3].

Among the solid propellants are:

• Fuels are usually metals in the form of dust such as magnesium, aluminum or zirconium.
• Oxidants can be: ammonium nitrate, sodium perchlorate, or similar substances [2].

Advantage:

1. They are simple to design.
2. They are inexpensive.
3. The solid propellant can be stored for a long time in the rocket before its takeoff. [1], [2].

Disadvantages:

1. Once the reaction has begun, it is not possible to regulate or stop it.
2. Initially calculated thrust can not be controlled after the engine is started.
3. They do not have refrigeration for their elements, so the duration of the ignition can not be prolonged [1], [2].