INDICATORS ON UNDERWATER NUCLEAR TEST 'UMBRELLA' (1958) YOU SHOULD KNOW

With test moratoriums on the horizon, American weapons labs rushed out many new models. A hard deadline for testing was established at midnight (0000 hrs), 31 October 1958, as negotiations had been set to begin that day, as well as routine exhibits it, with 29 tests executed in October, four of them on the last day. One other test was cancelled mai