Andrei Dmitriyevich Sakharov (1921-1989) was a Russian physicist and, later in his life, an anti-nuclear and anti-Communist activist.
During his time as a physicist, he helped create the hydrogen bomb during the burgeoning Cold War. However, he began to speak out against Communist repression, causing him to be imprisoned during the 1980s. He was award the Nobel Peace Prize in 1975 "for his opposition to the abuse of power and his work for human rights."[1]
Andrei Sakharov was an atheist.[2]