The one building I actually went in while walking around the Washington Mall (not counting monuments/memorials) was the Smithsonian National Air and Space Museum. I was somewhat pressed for time and hadn’t made it to the capitol yet so I didn’t spend nearly as much time here as I’d have liked to, but I did make it through the obvious rooms that had space artifacts in them.
I got scolded for trying to take a picture while standing in the line for security, so here’s my picture of Space Ship One from inside the security barrier:
Of course the National Air and Space museum has the Apollo 11 (first manned moon landing) capsule. It’s in the lobby, along with the capsules from Mercury Friendship 7 (first manned US orbital flight) and Gemini 4 (first US space walk).
Also posted as the header picture for this post, one of the several airplanes hanging from the ceiling in the lobby (aka the “Milestones of Flight” gallery) was an X-15 rocket plane:
You can see the Mercury and Gemini capsules underneath the rear of the plane.
At the east end of the ground floor hall is the ground test article for the Apollo Lunar Module:
I skipped the skylab exhibit (there’s one in Houston) and apparently didn’t take a picture of the Hubble mockup/model, but I did get a good picture of the Apollo-Soyuz Test Project display:
Here’s a picture of a Nazi V-1, included largely because behind it to the left you can see the model of the Hubble Space Telescope.
Having posted a picture of a V-1 I might as well follow it up with a V-2: