I have a pretty good one called “NASA: 50 Years of Space Exploration.” It’s 5 dvds, mostly of archival launch, mission control, space footage, etc. that’s voiced over, ranging from the early, Vanguard and Explorer days until the present. I’m not sure if it truly fits into the category of “documentary,” and there is little about the Soviet side of the space race. Still a good deal though…I picked up the set for $15 at best buy a while back.