After the Mysteries of Space and Sky 2014 Conference, we had the opportunity to visit the Smithsonian Air and Space Museum in downtown Washington DC. This was my first time visit and driving and parking downtown is to put it bluntly, a pain. If you get a chance to get a bus ride or taxi, that's probably a better way to go. Downtown DC is full of extraneous ad hoc political activity also. When we were there, streets were blocked off due to marches, and there were demonstrations everywhere with posters and banners. This area is definitely the hub of the political washtub. Once you get inside the museum of your choice, and there are a lot to choose from, it's all good.
This year's Society of Scientific Exploration meeting is going to be held in the DC area and they are having a bus trip to the Air and Space Museum on Friday afternoon May 29th. This would be the perfect way to see the museum.
There is a row of banners in front of the monument above the grass line and there is still work being done on the Capitol dome. (Maybe they are still recovering from Independence Day.)
Once inside the museum, the displays are fantastic.