The Apollo Spacecraft
Apollo was a three-part spacecraft: the command module (CM), the crew's quarters and flight control section;
the service module (SM) for the propulsion and spacecraft support systems (when together, the two modules are called
CSM); and the lunar module (LM), to take two of the crew to the lunar surface, support them on the Moon, and return them
to the CSM in lunar orbit.
The flight mode, lunar orbit rendezvous, was selected in 1962. The boosters for the program were the
Saturn IB for Earth orbit flights and the Saturn V for lunar flights.