If I had all the time in the world, I could lose days of my life at the new-to-me NASA History Homepage. They’ve assembled not just the technical details but information on the people, the management of the program, and the politics involved, so you can get a number of perspectives if you poke around enough. I loved looking at the technical diagrams of the various spacecraft, even if I don’t really understand them. And they’ve put tons of their books, reports, and other publications on-line as well. I just wish more of the content was in downloadable pdf (as well as the nicely searchable html) so one could flip through entire documents with more ease.
Glimpses of the websurfing habits of a computer science professor, obsessive crafter, occasional gamer, and all around geek