The Apollo program was a United States human spaceflight program carried out from 1961 to 1972 by the National Aeronautics and Space Administration (NASA), which landed the first astronauts on the Moon. The program used the Saturn IB and Saturn V launch vehicles to lift the Command/Service Module (CSM) and Lunar Module (LM) spacecraft into space, and the Little Joe II rocket to test a launch escape system which was expected to carry the astronauts to safety in the event of a Saturn failure. Uncrewed test flights beginning in 1966 demonstrated the safety of the launch vehicles and spacecraft to carry astronauts, and four crewed flights beginning in October 1968 demonstrated the ability of the spacecraft to carry out a lunar landing mission.