On April 12, 1961, the Russian cosmonaut became the first human launched into space. His 108-minute mission made him a world-wide hero. Gagarin died in 1968 at the age of 34 in a crash during a jet training flight.
Also, on the same date in 1981, the first U.S. Space Transport System -- to become known as the Columbia space shuttle -- was launched from Cape Canaveral, Fla., with astronauts Robert Crippen and John Young aboard.
The National Aeronautics and Space Administration said that initial Columbia launch, STS-1, marked the only time a new spacecraft has been launched with a crew aboard on its first flight.
Notable deaths of 2014 [PHOTOS]