Apollo 4 was the first uncrewed test flight of the Saturn V rocket in 1967.
Launched from Kennedy Space Center on November 9, 1967, Apollo 4 was the first launch in the Apollo program to use the complete Saturn V vehicle. Its main purpose was to test the powerful rocket and the Apollo command and service module together before crewed missions.
The mission lasted about nine hours and included a high-energy reentry test of the command module, simulating conditions expected when returning from the Moon. The spacecraft splashed down in the Pacific Ocean after completing two Earth orbits.
Apollo 4 is sometimes confused with Apollo 6, which was the second uncrewed Saturn V test flight. Apollo 8 followed as the first crewed Saturn V mission and became the first crewed mission to orbit the Moon.