Table 2 Specific impulses of Rocket Propellants.

Andrei Sakharov was a Soviet physicist who became, in the words of the Nobel Peace Prize Committee, "a spokesman for the conscience of mankind." He made many important contributions to our understanding of plasma physics, particle physics, and cosmology. He also designed nuclear weapons for two decades, becoming "the father of the Soviet hydrogen bomb" in the 1950s. After recognizing the dangers of nuclear weapons tests, he championed the 1963 U.S.-Soviet test ban treaty and other antinuclear initiatives.

From the 1960s onward, at great personal risk, Sakharov severely criticized the Soviet regime and ardently defended human rights against it. He won the Nobel Peace Prize in 1975.

Andrei Sakharov was born in Moscow, Russia, to a family of the intelligentsia on May 21, 1921. His father, Dmitri, taught college physics and wrote textbooks and popular science books. Sakharov...