Granted the launch facilities are not exactly open to the public, but there are no metal detectors and they don't take away your pocket knife either.

From Smithsonian — Visitor Information: Security and Policies:

“Do not bring any sharp items into the museums such as knives (including pocket or ‘Swiss Army’-style knives), screwdrivers, scissors, nail files, corkscrews, etc. Other items not permitted include firearms, pepper spray, and Mace.”

I've walked through with a SAK champ, but I also knew it was against the rules and was prepared to be denied.

You Millage May Vary.

does the smithsonian afraid of animals reanimating into real life?