The Apollo spacecraft was composed of three parts designed to accomplish the American
The design was based on the
The LES was jettisoned during launch upon reaching the point where it was no longer needed, and the SLA remained attached to the launch vehicle's upper stage. Two unmanned CSM's, one unmanned LM and one manned CSM were carried into space by
The major part of the Apollo spacecraft was a three-man vehicle designed for Earth orbital, translunar, and lunar orbital flight, and return to Earth. This consisted of a command module supported by a service module, built by North American Aviation (later
The command module was the control center for the Apollo spacecraft and living quarters for the three crewmen. It contained the pressurized main crew cabin, crew couches, control and instrument panel,
The service module was unpressurized and contained a main
A major portion of the service module was taken up by propellant and the main rocket engine. Capable of multiple restarts, this engine placed the Apollo spacecraft into and out of lunar orbit, and was used for mid-course corrections between the Earth and the Moon.
The service module remained attached to the command module throughout the mission. It was jettisoned just prior to reentry into the Earth's atmosphere.