A typical space program, such as say, launching of a communication satellite begins with first somebody deciding that they need to put a communication ( or any other ) satellite into orbit. Then a slot has to be found out for the new satellite in the space, since we cannot just put a satellite anywhere in the space. In case of a communications satellite, it has to be put into a geostationary orbit. There is an international agency (Whose name I forget ) that keeps tab on where to keep the satellite. A slot has to be procured from them for the positioning of the craft.

Having accomplished that, the next task is to allocate(or decide) the frequencies which the satellite will be using. In case of a communications satellite this will be often the C Band, and the Ku Band. Then we will have to decide for how much time the satellite will be operational (say 5 years), and what are the exact pay-loads, and what will be the power required. All this has a direct bearing on the design of the satellite.

After having decided the contents, materials, of the satellite, it is actually built and launched into space with the help of a rocket ( More on these later ). A communications satellite will usually be launched into the orbit by a cryogenic rocket or a space shuttle. There are quite a few agencies like Ariane and NASA which have the capability to launch such rockets. India is still one or two years away from launching their first completely indigenously built cryogenic rocket, although we have launched satellites into orbit by using Russian made cryogenic engines.

So this is the overview on how a satellite is launched. For more on satellites see the other links. Ditto for rockets.

For deciding on how much on-board fuel is carried aboard the satellite and the control systems of the satellite, we have to take into account the various disturbances that can act upon the satellite. This has been segregated into a different branch of physics and named celestial mechanics. I will deal with these without using any math.