Today is the 100th anniversary of the birth of a giant of space exploration -- Sergey Korolyov (sometimes also transliterated as Sergei Korolev). For much of the 20th century, Korolyov was the prime driving factor behind the Soviet space program. He led the efforts to launch Sputnik, put Yuri Gagarin into orbit, and hold up the USSR's end of the race to the moon. Yet during Korolyov's life, even his existence was a Soviet state secret -- he was only ever publicly referred to as the "Chief Designer." After his death, he finally received some recognition for his accomplishments, yet many parts of Korolyov's life and work were more rumor than fact until after the collapse of the USSR.

Tune in this week, and you'll learn more about the impressive contributions made by a man who, until recently, was almost unheard of.