Two comments: first, you will probably not see any " Science." You may see the results of engineering feats ... but check out places well before you go too far out of your way; some " science sites" that I am aware of actually consist of two parts: the places where science is done and where they really wish you would go away and leave them alone, and the other parts -- where the "outreach" people have set up demos. The Air and Space Museum in D.C. is a fantastic place to visit, and I'd recommend that, but (for example) you should not expect to see the science or engineering behind the Blackbird. If you saw any genuine supercomputers, you'd see a large room full of cabinets, but no science behind the calculations being done (mostly by people in other locations :-)
Lots to see, and fun, but be thoughtful about what you are looking for.