Upshot-Knothole Simon was a nuclear detonation conducted as part of the U.S. Operation Upshot-Knothole nuclear testing program. Simon was conducted on 25 April 1953 at the Nevada Test Site, and tested the TX-17/24 thermonuclear weapon design which had a yield of 43 kilotons. Test: Simon Time: 12:30 25 April 1953 (GMT) 04:30 25 April 1953 (local) Location: Nevada Test Site, Area 1 Test Height and Type: 300 Foot Tower Yield: 43 kt