Tsiolkovsky (or Ziolkovsky), Konstantin Eduardovich (18571935), a Russian rocket pioneer who is generally regarded as the father of space travel. He was the first to explain in detail how rockets could be used to launch space vehicles, in an article in 1903. He also proposed the use of liquid fuel for rockets, discussed the advantages of multistage rockets, and suggested solutions for certain space problems such as weightlessness.

Tsiolkovsky never built any rockets to test his theories and his writings originally attracted little attention. During the 1920's, his work was rediscovered and he became a national hero.

Tsiolkovsky was born in Izhevsk, about 600 miles (965 km) northeast of Moscow. A childhood illness left him almost totally deaf; denied admission to college, he learned mathematics and physics by studying on his own. He taught school from 1876 to 1920.