On this day in 1968, Apollo 5 launched from Cape Canaveral.
Apollo 5 was the first orbital flight of the Apollo Lunar Module on a Saturn IB rocket. Unmanned, the flight’s objectives were to test the Lunar Module’s descent and ascent engines and stages, as well as to simulate a landing abort, in which the ascent stage engine would be fired while still attached to the descent stage.
While problems cropped up in the programming for the descent engine, missions controllers were still able to carry out the needed tests to accomplish all of Apollo 5’s mission goals. Notably, the descent engine became the first throttleable rocket engine fired in space.
Apollo 5 was instrumental in proving the Apollo system, and the incredible success of the Apollo program could be partly attributed to this shakedown cruise.