I used to live in Herndon and commuted through Great Falls on my way to TRW. One of the worst jobs I've ever had. A true beltway bandit and a waste of 4 years of my life. I'm about an hour and a half south of there much of the time or an hour to the north in MD.
I assume by museum you mean the Udvar-Hazy Center? I've been there a number of times. Impressive stuff. Did you see the cemetery on the model from Close Encounters? I got a laugh when I saw that. I think there is a VW micro bus along with many other out of place items.
I wonder how many people have visited both the Udvar-Hazy Center and the Alexander Graham Bell Museum where the Silver Dart is on display along with Bell's HD-4 hydrofoil which held the marine speed record for some years.