You can check Archives' holdings at the official National Archives website as well as at a Google website. At the moment, the pilot program covers 101 films, including some U.S. government World War II newsreels; several NASA documentaries on the history of the spaceflight program; and some documentaries on the history and establishment of a nationwide system of national and state parks, Boulder Dam, the Civilian Conservation Corps, and the Tennessee Valley Authority.
The kids and I took a look through the links and found the following gems (the download takes too long for us dial-up types, but one can hope):
- "The Eagle Has Landed", about the 1969 moon landing
- "Who's Out There", a 1975 exploration of extraterrestrial life narrated by Orson Welles, which made me realize that someone at NASA had a sense of humor