Andrei Dmitriyevich Sakharov, the Soviet physicist who helped build the USSR's first hydrogen bomb, is awarded the Nobel Prize for Peace in recognition of his struggle against "the abuse of power and violations of human dignity in all its forms." Sakharov was forbidden by the Soviet government from personally traveling to Oslo, Norway, to accept the award. Born in Moscow in 1921, Sakharov studied physics at Moscow University and in June 1948 was recruited into the Soviet nuclear weapons program. In 1948, after detonating their first atomic bomb, the Soviets joined the United States in the race to develop the hydrogen bomb, a weapon theorized to be dozens of times more powerful than the nuclear bombs dropped on Hiroshima and Nagasaki. Sakharov's concept of the "Layer Cake" bomb showed some promising results, but in late 1952 the Americans successfully detonated the world's first "super bomb." The Soviet team rushed to catch up and, with the aid of Soviet espionage, settled on the same winning concept as the Americans--radiation implosion. On November 22, 1955, the Soviet Union successfully detonated its first hydrogen bomb. Although Sakharov was decorated with numerous Soviet scientific honors for his achievement, the scientist became increasingly concerned with the implications of the terrifying weapon, and he later regretted his part in its creation. In 1957, his concern about the biological hazards of nuclear testing inspired him to write a damning article about the effects of low-level radiation, and he called for the cessation of nuclear tests. The Soviet government kept his criticism quiet until 1969, when an essay Sakharov wrote was smuggled out of the country and published in The New York Times. In the essay, he attacked the arms race and the Soviet political system and called for a "democratic, pluralistic society free of intolerance and dogmatism, a humanitarian society that would care for the Earth and its future." Following the publication of his essay, Sakharov was fired from the weapons program and became a vocal advocate of human rights. In 1975, he was the first Soviet to win the Nobel Peace Prize. After he denounced the 1979 Soviet invasion of Afghanistan, Soviet authorities were quick to respond, exiling him to Gorky, where he lived in difficult conditions. In December 1986, Sakharov's exile ended when Soviet leader Mikhail Gorbachev invited him to return to Moscow. He was subsequently elected to the Congress of People's Deputies as a democratic reformer and appointed to the commission responsible for drafting a new Soviet constitution. Sakharov died in 1989.