The main part of the space shuttle is the orbiter. This contains the flight deck, living quarters and the payload bay. The payload bay is a special compartment that carries satellites or other scientific equipment. At the time of the launch, a large fuel tank and two extra boosters are attached to the orbiter. The fuel tank supplies fuel to the main engines at the rear of the orbiter and extra power is provided by the two boosters. Around two minutes into the flight, the boosters are ejected and are collected, empty, from the sea. The used fuel tank will have broken up in the atmosphere and therefore cannot be retrieved.

A smaller pair of engines, located on the shuttle orbiter, is fired to lift the spacecraft into its orbit. The same engines are used again at the end of the mission to bring the orbiter back down into the atmosphere. To enable the orbiter to glide smoothly through the atmosphere it is equip with protective, heat-resistant tiles and blankets. These can easily be replaced between missions.