With the Soviets successfully testing their own nuclear weapons, the race was officially on. Little more than a month after the "Joe 1" test, the United States began expanding its production of uranium and plutonium. By the start of 1950, President Harry S. Truman announced the U.S. would continue research and development on "all forms of atomic weapons."
This "all forms" part was important. Initially, scientists working for the Manhattan Project considered two possible designs for an atomic bomb. They eventually chose to create a fission bomb, in which neutrons fired toward the nuclei of uranium or plutonium set off a massive chain reaction. This type of bomb was used on Hiroshima, Nagasaki and Bikini Atoll. A physicist at Los Alamos, Edward Teller, suggested a thermonuclear fusion bomb, or hydrogen bomb. A fusion bomb operates by forcing together deuterium and tritium, two light isotopes of hydrogen. The resulting explosion would be theoretically many times more than that of a fission device, and almost without limit. Time didn't permit the completion of a fusion bomb, but Teller pushed for a chance to complete the device in order to keep one step ahead of the Russians.
On Nov. 1, 1952, the U.S. detonated the world's first hydrogen bomb, code-named "Mike," on the Enewetak Atoll of the Marshall Islands. The resulting explosion was about the same as 10 million tons of TNT, or 700 times greater than the fission bomb dropped on Hiroshima. The cloud produced by the explosion was 25 miles high and 100 miles wide, and the island on which it exploded simply disappeared, leaving nothing but a gaping crater. Again, Klaus Fuchs had delivered early information on the hydrogen bomb designs along with the fission bomb information, and by late 1955 the Soviets tested their own design.
One of the more distressing events of the 1950s was another Soviet development -- the launch of Sputnik 1 on Oct. 4, 1957. The satellite was the first object to be launched into space by an intercontinental ballistic missile (ICBM), and the achievement caused a great scare in the U.S. If the Soviets could put a satellite into space, they could do the same thing with a nuclear warhead. Now, instead of having sufficient warning time for a nuclear attack by monitoring incoming airplanes, a missile could hit a target in less than an hour.
The 1950s also included the expansion of the nuclear "club," or the group of nations with tested nuclear weapons. England had worked together with the U.S. on the nuclear bomb design, but because of limited funds during the war, their contributions were mainly theoretical. This changed on Oct. 3, 1952, when the English tested their first nuclear bomb off the coast of Australia.
The race during the '50s started off quickly, but the real dangers didn't become evident until the next decade. To learn about nuclear weapons in the '60s, read the next page.