Andrei Dmitrievich Sakharov was born in , the son of a physics teacher. In 1938, he entered Moscow State University. When the university was evacuated during World War II, he attended and went on to graduate from university in Aşgabat (now Turkmenistan). After graduating, he was assigned laboratory work in Ulyanovsk. In 1943, he married Klavdia Alekseyevna Vikhireva, with whom he raised three children until her death in 1969. In 1945, the family returned to Moscow and Sakharov began to study at the Theoretical Department of FIAN (the Physical Institute of the Soviet Academy of Sciences). He researched cosmic rays, and received his Ph.D. in 1947. In 1948, Sakharov participated in the Soviet atomic bomb project. The first Soviet atomic device was tested in 1949. After moving to Sarov in 1950, Sakharov played a key role in the next stage, the development of the hydrogen bomb. The first Soviet fusion device was tested in 1953, the same year Sakharov received his D.Sc. degree, was elected a full member of the Soviet Academy of Sciences, and was awarded a Hero of Socialist Labor titles. He continued to work at Sarov, playing a key role in the development of the first megaton-range Soviet hydrogen bomb, which was tested in 1955. He became troubled by the moral and political implications of his work, and began to campaign against nuclear weapons. He played a role in the 1963 Partial Test Ban Treaty, which was signed in Moscow. After 1965, Sakharov returned to theoretical science and began working on particle physics and cosmology. In 1967, he wrote to the Kremlin and urged leaders to "take the Americans at their word" and accept their proposal for a ban on missile defense. In 1972, he married fellow human rights activist Yelena Bonner. In 1975 he was awarded the Nobel Peace Prize, although he was not allowed to travel to Norway to accept it. In 1980, he was arrested for public protests against the Soviet Invasion of Afghanistan and sentenced to exile in the city of Gorky. In 1986, he was released and allowed to return to Moscow. In 1989, he was elected to the new parliament and co-led the opposition party.