Click the arrow to watch the film. Video source: Jeff Quitney YouTube channel.
What goes up must come down.
Where it comes down is the topic of this week's Retro Saturday.
Apollo Atmospheric Entry Phase is a 25-minute 1968 NASA documentary explaining how NASA would calculate the re-entry and landing time and trajectory for the Apollo crew vehicles.
At the time of this film, NASA had yet to send astronauts to the Moon. That would happen in late December 1968, with the Apollo 8 flight that orbited the Moon on Christmas Day.