Assembly line of the SR-71 Blackbird at Skunk Works. Photo: Wikipedia Public Domain

Wikipedia – 092822
This work is in the public domain in the United States because it is a work prepared by an officer or employee of the United States Government as part of that person’s official duties under the terms of Title 17, Chapter 1, Section 105 of the US Code.
https://commons.wikimedia.org/wiki/File:SR71_factoryfloor_SkunkWorks.jpg