This documentary could have been so much better but a lot of it consists of stills with a voice over that is sleep inducing.
In the Mercury section the launch of a Mercury rocket is mentioned only to see footage of a Saturn V which is criminally bad. I would not recommend this as an overall view of NASA and manned space flight, a MUCH better alternative is 'When We Left Earth'. This is for completists only, I have watched most of disc one and that was enough for me I cannot see myself revisiting this any time soon.