49 years ago today, at 5:48 p.m. on Jan. 22, 1968, a stocky Saturn IB roared into the sky from Pad 37B at Kennedy Space Center taking the Lunar Module on its first flight into space. The uncrewed Apollo 5 mission would put LM-1 through a series of tests in low-Earth orbit, making sure that the vehicle was ready to carry America’s astronauts to the Moon, deliver them to its rugged surface, and bring them back safely.

Watch a video from NASA’s Johnson Space Center below showing details of the Apollo 5 mission, including the launch:

The Apollo 5 mission lasted just over 11 hours, and tested various performance aspects of a legless and windowless version of the Lunar Module, in particular its ascent and descent engines—the latter of which was the first throttleable engine used entirely in space.

Many astronauts from future Apollo missions were on site at mission control in Houston for the test, as they would very soon be trusting the success of their missions—and their lives—to the performance of this crucial space vehicle.

Learn more about Apollo 5 here.

The film above is in the public domain and was remastered and uploaded to YouTube by Jeff Quitney.