The body of a satellite, also known as the bus of a satellite, holds all of the scientific equipment and other necessary components of the satellite. Satellites combine many different materials to make up all of their component parts. Since satellites are essentially pieces of scientific or communications equipment that must go into space, engineers must design a bus that will take the equipment safely into space.

There are several goals that engineers must accomplish when choosing materials for the satellite's bus. Among these are:

• Outer Layer: protecting the satellite from collisions with micrometeorites, or other particles floating in space
• Anti-radiation: protecting the satellite from the radiation of the sun
• Thermal Blanketing: using thermal blanketing to keep the satellite at a comfortable temperature for the instruments to function
• Conduction: conducting heat away from the satellite's vital instruments
• Structural Support
• Connecting Materials

Generally, the smaller the satellite, the better. When choosing the materials for a bus, the following factors are also usually taken into consideration: cost, weight, longevity (how long the material will last), and whether the material has proven to be functional on other satellites before.