Apollo 5 made the first uncrewed test flight of the Lunar Module.
Launched on January 22, 1968, Apollo 5 carried Lunar Module-1 into Earth orbit atop a Saturn IB rocket. The mission was designed to test the lunar lander’s propulsion, staging, guidance, and ability to perform the maneuvers needed for descent toward the Moon and ascent back to lunar orbit.
The flight did not follow its original plan exactly. After separation from the S-IVB stage, an automatic abort occurred when the Apollo Guidance Computer detected that the vehicle was not accelerating as expected. Mission Control, led by flight director Gene Kranz’s team, switched to an alternative sequence that still achieved the main test objectives.
Apollo 5 is often confused with Apollo 4, Apollo 6, or Apollo 9. Apollo 4 and Apollo 6 tested the command-and-service-module and Saturn V combination, while Apollo 9 was the first crewed mission to test a Lunar Module in Earth orbit. Apollo 5 was the crucial uncrewed pathfinder for the lander itself.