Announced United States Nuclear Tests - By Date Date (GCT) Location __ “Operation Argus Argus| 08/27/58 South Atlantic Rocket WeaponsEffects 1-2 kt Argusll About 300 miles altitude, South 49.5 degrees, West 8.2 degrees 08/30/58 South Atlantic Rocket WeaponsEffects 1-2 kt Argus tli 09/06/58 South Atlantic Rocket WeaponsEffects 1-2 kt About 300 miles altitude, South 38.5 degrees, West 11.5 degrees About 300 miles altitude, South 48.5 degrees, West 9.7 degrees Operation Hardtack I! Otero 09/12/58 NTS Shaft Safety Experiment 38 tons Bernalitio Unstemmed hole Radioactivity not detected off site 09/17/58 NTS Shaft - Safety Experiment 15 tons Eddy 09/19/58 NTS Balloon WeaponsRelated 83 tons Luna Unstemmed hole Radioactivity not detected off site 09/21/58 NTS Shaft Safety Experiment 1.5 tons Mercury No radioactive release detected 09/23/58 NTS Tunnel Safety Experiment Slight Valencia Unstemmedhole Radioactivity not detected off site 09/26/58 NTS Shaft Safety Experiment 2 tons Mars Slight venting, radioactivity not detected off site 09/28/58 NTS Tunnel Safety Experiment 13 tons Mora 09/29/58 NTS Balloon WeaponsRelated 2 kt Unstemmed hole -10-