The Cross-Domain Solution, or CDS, hardware is displayed here Feb. 12, 2020, at Arnold Air Force Base, Tenn. Engineers at Arnold have researched the use of a CDS interface to allow plant operations systems outside of the Plant Control Room to remain unclassified during classified test programs. (U.S. Air Force photo by Deidre Ortiz) (This image has been altered by obscuring items for security purposes.)