Chimps in Space: Ham, Enos Flew Mercury Capsules Before Astronauts

NASA used animals before sending humans into space.

Chimps, the First Space Explorers Before Mercury Astronauts

A monkey is fitted with an oxygen mask during a test at the U.S. Air Force Wright Air Development Center, near Dayton, Ohio, Jan. 20, 1956. (Bettmann/CORBIS)

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