Apollo 5 (launched January 22, 1968), also known as AS-204, was the uncrewed first flight of the Apollo Lunar Module (LM) that would later carry astronauts to the surface of the Moon. The Saturn IB rocket bearing the LM lifted off from Cape Kennedy on January 22, 1968. The mission was successful, though due to programming problems an alternate mission to that originally planned was executed.

Like Apollo 4, this flight was long-delayed, due in part to setbacks in development of the LM at Grumman, the manufacturer. The original Saturn IB rocket that was to take the first LM (LM-1) to space was taken down during the delays and replaced with the one from Apollo 1 (in which the fire that killed three astronauts had taken place). LM-1 arrived at the Kennedy Space Center in June 1967; the following months were occupied in testing and placing the LM atop the Saturn IB. After final delays due to equipment trouble, the countdown began on January 21, 1968, and the space vehicle was launched the following day.

Once the craft reached orbit and the LM separated from the S-IVB booster, the program of orbital testing began, but a planned burn was aborted automatically when the Apollo Guidance Computer detected the craft was not going as fast as planned. Flight Director Gene Kranz and his team at Mission Control in Houston quickly decided on an alternate mission, during which the mission's goals of testing LM-1 were accomplished. The mission was successful enough that a contemplated second uncrewed mission to test the LM was cancelled, advancing NASA's plans to land an astronaut on the Moon by the end of the 1960s.