Has Texas surrendered its rights to the Johnson Space Center? Otherwise the mere fact that the Feds own it does not make it a Federal enclave. Because Texas was a sovereign nation before joining the union, the Federal Government never "owned" Texas land.
I know of Military Bases where the State of Texas has surrendered its sovereign authority, so a DWI there can be a Federal crime. I wouldn't be surprised if the Feds demanded such a surrender in exchange for the billions they have spent at Johnson Space Center.
You are sweating the small stuff. The Feds may think they own stuff here but we all know who it really belongs to:’)
In terms of the law, JSC *is* a Fed military base.
I believe the property actually belongs to Rice University, or used to.
Section 8, US Constitution, regarding powers of Congress:
To exercise exclusive Legislation in all Cases whatsoever, over such District (not exceeding ten Miles square) as may, by Cession of particular States, and the acceptance of Congress, become the Seat of the Government of the United States, and to exercise like Authority over all Places purchased by the Consent of the Legislature of the State in which the Same shall be, for the Erection of Forts, Magazines, Arsenals, dock-Yards, and other needful Buildings;National parks, national monuments (eg, the park in Philly where the Liberty Bell sits), and post offices are federal land. Something for CCW holders to remember.