when did the soviets explode first atomic bomb
Soviet atomic bomb project On 29 August 1949, the Soviet Union secretly conducted its first successful weapon test (First Lightning), based on the U.S. design at the Semipalatinsk in Kazakhstan.[2]
Alonso Álvarez de Pineda
Atomic bombings of Hiroshima and Nagasaki Groves expected to have another atomic bomb ready for use on August 19, with three more in September and a further three in October.[86] On August 10, he sent a memorandum to Marshall in which he wrote that "the next bomb ... should be ready for delivery on the first suitable weather after 17 or 18 August." Marshall endorsed the memo with the hand-written comment, "It is not to be released over Japan without express authority from the President",[86] something Truman had requested that day. This modified the previous order that the target cities were to be attacked with atomic bombs "as made ready".[226] There was already discussion in the War Department about conserving the bombs then in production for Operation Downfall, and Marshall suggested to Stimson that the remaining cities on the target list be spared attack with atomic bombs.[227]
Atomic bombings of Hiroshima and Nagasaki By August 1945, the Allies' Manhattan Project had produced two types of atomic bombs, and the 509th Composite Group of the United States Army Air Forces (USAAF) was equipped with the specialized Silverplate version of the Boeing B-29 Superfortress that could deliver them from Tinian in the Mariana Islands. Orders for atomic bombs to be used on four Japanese cities were issued on July 25. On August 6, the U.S. dropped a uranium gun-type (Little Boy) bomb on Hiroshima, and American President Harry S. Truman called for Japan's surrender, warning it to "expect a rain of ruin from the air, the like of which has never been seen on this earth." Three days later, on August 9, a plutonium implosion-type (Fat Man) bomb was dropped on Nagasaki. Within the first two to four months following the bombings, the acute effects of the atomic bombings had killed 90,000–146,000 people in Hiroshima and 39,000–80,000 in Nagasaki; roughly half of the deaths in each city occurred on the first day. During the following months, large numbers died from the effect of burns, radiation sickness, and other injuries, compounded by illness and malnutrition. In both cities, most of the dead were civilians, although Hiroshima had a sizable military garrison.